> Source: [sk30583](https://support.checkpoint.com/results/sk/sk30583) # sk30583 - What is FW Monitor? | Property | Value | |----------|-------| | Solution ID | sk30583 | | Date Created | 2005-03-02 | | Last Modified | 2026-08-13 | | Technical Level | General | | Products | Security Gateway | | Versions | R82.10, R82, R81.20, R81.10 (EOS), R81 (EOS) | ## Solution **Table of Contents:** 1. Introduction 2. Warnings 3. FW Monitor Features 4. FW Monitor Functionality 5. FW Monitor Syntax and Usage 1. Syntax 2. Comparison with TCPdump 3. Using the UUID feature 6. SecureClient Syntax 7. Capture Examples of "-e" flag 1. Usual Capture 2. Host Specific Capture 3. Port Specific Capture 4. Protocol Specific Capture 5. Protocol Options Specific Capture 6. Bytes Specific Capture 7. Network Specific Capture 8. Some Examples 8. Capture Examples of "-F" flag 1. Usual Capture 2. Host Specific Capture 3. Port Specific Capture 4. Protocol Specific Capture 9. Related Documentation 10. Related Solutions (1) Introduction {#Introduction} -------------------------------- Check Point's ***FW Monitor*** is a powerful built-in tool for capturing network traffic at the packet level. The *FW Monitor* utility captures network packets at multiple capture points along the FireWall inspection chains. These captured packets can be inspected later using the WireShark (available for free from [www.wireshark.org](http://www.wireshark.org)). (2) Warnings {#Warnings} ------------------------ * Anything related to policy installation or policy unloading on Security Gateway, will cause *FW Monitor* to exit. * It is supported to run *only* a single instance of *FW Monitor* at any given time. * Do not modify Check Point kernel tables used in the security policy while *FW Monitor* is running. Otherwise, unexpected behavior may result (including a system crash). * Packets are defragmented as they leave the Security Gateway in both the inbound and outbound directions. * If SecureXL is enabled on the Security Gateway, then *FW Monitor* and *tcpdump* will show only the **non**-accelerated packets (e.g., 'TCP SYN' will be shown, and 'TCP ACK' will not). * **Important Note:** Traffic captures can be misleading when working with SecureXL since both FW Monitor and TCPdump do not always show 'real' packets that are going out to the network. This is related to the way the SecureXL kernel driver is attached to the network adapter itself. When using SecureXL to confirm whether packets are being handled correctly, either capture the traffic on the directly connected router / switch, or disable SecureXL. * From R80.20 Jumbo Hotfix Accumulator Take 73, the FW Monitor supports monitoring of accelerated traffic by default. * From R80.20, the FW Monitor can show the traffic accelerated with SecureXL. * From R80.30 Jumbo Hotfix Accumulator - General Availability Take 215, added ability to FW Monitor to support monitoring of accelerated traffic by default, except for the "`-e`" flag for FW Monitor, which is not supported on SecureXL. ### Monitored traffic * From R80.20, the 1st accelerated packet is monitored only in the inbound (i). * From R80.20 Jumbo Hotfix Accumulator Take 73, the accelerated inbound (i) traffic and accelerated outbound (O) traffic is monitored in the Fast Path. * From R80.20 Jumbo Hotfix Accumulator Take 117, the Slow Path, the Medium Path, and the Fast Path are monitored. * From R80.30, the default behavior is like before R80.20 Jumbo Hotfix Accumulator Take 72. * From R80.40 and in R80.30 Jumbo Hotfix Accumulator Take 215 and above, the default behavior is to monitor all traffic. ### Filtering options * From R80.20 Jumbo Hotfix Accumulator Take 73, using the "`-e`" flag will not filter the accelerated traffic (all accelerated traffic is monitored). To filter the accelerated traffic, use the "`-F`" flag. * From R80.20 Jumbo Hotfix Accumulator Take 117, using the "`-e`" flag will filter out all accelerated traffic. To filter and monitor the accelerated traffic, use the "`-F`" flag. * You can freely use the "-F" flag in these versions: * R80.40 and above * R80.30 Jumbo Hotfix Accumulator Take 215 and above * R80.20 Jumbo Hotfix Accumulator Take 173 and above If you use the "`-e`" flag, the filtering applies to the non-accelerated traffic, and accelerated traffic is not shown at all. * **Important:** A limitation exists when you use filters ("`-F`" flag for "`fw monitor`" and "`-F`" / "`-H`" flags for "`fw ctl debug`") for both "`fw monitor`" and "`fw ctl debug`" simultaneously. Running any of these commands with a debug filter overrides the debug filter used for pre-existing debug commands. **Currently, it is not supported to run both of these commands simultaneously with a debug filter - "`fw monitor -F`" and "`fw ctl debug -F`" / "`fw ctl debug -H`".** Only the filter for the last command that was run is applied. The data for the previous command will stop being filtered as soon as a new command is run, which means that all data is received unfiltered. **This may have significant performance impact.** If you need filtered packet capture during a kernel debug "`fw ctl debug`" session, we recommend to use "`cppcap`" ([sk141412](https://support.checkpoint.com/results/sk/sk141412)) instead of "`fw monitor`". (3) FW Monitor Features {#FW Monitor Features} ---------------------------------------------- In many deployment and support scenarios, capturing network packets is an essential functionality. The *tcpdump* / *snoop* utilities are normally used for this task. The *FW Monitor* utility provides an even better functionality, but omits many of the requirements and the risks associated with these tools: * *No Security Flaws* *tcpdump* / *snoop* are normally used with NICs in promiscuous mode. Unfortunately, promiscuous mode allows remote attacks against these tools. Check Point's *FW Monitor* does not use promiscuous mode to capture packets. In addition, most firewalls' operating systems are hardened. In most cases, this hardening includes the removal of tools like *tcpdump* / *snoop*, because of their security risks. * *Available on FireWall Installations* *FW Monitor* is a built-in tool that does not need a separate installation, or licensing. * *Multiple Capture Positions within the FireWall Kernel Module Chains* *FW Monitor* allows capturing packets at multiple capture positions within the Security Gateway kernel module chains, both for inbound and outbound packets. This enables to trace a packet through the different layers of the Security Gateway. * *Same Tool and Syntax on All Platforms* *FW Monitor* is available on all different platforms. *tcpdump* / *snoop* are often platform-dependent, or have specific "enhancements" on certain platforms. *FW Monitor* and all its related functionality and syntax are identical across all platforms. Normally, Check Point kernel modules are used to perform several functions on packets, such as filtering, encryption and decryption, QoS, etc. *FW Monitor* adds its modules to capture packets. *FW Monitor* can capture all packets that are seen and/or forwarded by the Security Gateway. (4) FW Monitor Functionality {#FW Monitor Functionality} -------------------------------------------------------- There are different inspection points when a packet passes through a Security Gateway. **Note** - The Inbound and Outbound traffic direction relates to each specific packet, and not to the connection. * Inbound: |--------------------------|------------------------------------------|-----------------------------------------------------| | Name of inspection point | Relation to the FireWall Virtual Machine | Notion of inspection point in the FW Monitor output | | Pre-Inbound | Before the inbound FireWall VM | i (for example, `eth4:i`) | | Post-Inbound | After the inbound FireWall VM | I (for example, `eth4:I`) | | Pre-Inbound VPN | Inbound before decryption | id (for example, `eth4:id`) | | Post-Inbound VPN | Inbound after decryption | ID (for example, `eth4:ID`) | | Pre-Inbound QoS | Inbound before QoS | iq (for example, `eth4:iq`) | | Post-Inbound QoS | Inbound after QoS | IQ (for example, `eth4:IQ`) | * Outbound: |--------------------------|------------------------------------------|-----------------------------------------------------| | Name of inspection point | Relation to the FireWall Virtual Machine | Notion of inspection point in the FW Monitor output | | Pre-Outbound | Before the outbound FireWall VM | o (for example, `eth4:o`) | | Post-Outbound | After the outbound FireWall VM | O (for example, `eth4:O`) | | Pre-Outbound VPN | Outbound before encryption | e (for example, `eth4:e`) | | Post-Outbound VPN | Outbound after encryption | E (for example, `eth4:E`) | | Pre-Outbound QoS | Outbound before QoS | oq (for example, `eth4:oq`) | | Post-Outbound QoS | Outbound after QoS | OQ (for example, `eth4:OQ`) | Let us examine a TCP handshake in the following topology: *\[Client\] --- (eth1)\[Security Gateway\](eth2) --- \[Server\]* 1. *TCP **SYN***` from [Client] will pass through `*Pre-Inbound*` and `*Post-Inbound*` on interface `**eth1**`:` *\[Client\] --- (eth1) {*Pre-Inbound* + *Post-Inbound*} \[Security Gateway\](eth2) --- \[Server\]* 2. *TCP **SYN*** from \[Client\] will pass through *Pre-Outbound* and *Post-Outbound* on interface **eth2**: *\[Client\] --- (eth1)\[Security Gateway\] {*Pre-Outbound* and *Post-Outbound*} (eth2) --- \[Server\]* 3. *TCP **SYN-ACK*** from \[Server\] will pass through *Pre-Inbound* and *Post-Inbound* on interface **eth2**: *\[Client\] --- (eth1)\[Security Gateway\] {*Pre-Inbound* + *Post-Inbound*} (eth2) --- \[Server\]* 4. *TCP **SYN-ACK*** from \[Server\] will pass through *Pre-Outbound* and *Post-Outbound* on interface **eth1**: *\[Client\] --- (eth1) {*Pre-Outbound* and *Post-Outbound*} \[Security Gateway\](eth2) --- \[Server\]* 5. *TCP **ACK*** from \[Client\] will pass through *Pre-Inbound* and *Post-Inbound* on interface **eth1**: *\[Client\] --- (eth1) {*Pre-Inbound* + *Post-Inbound*} \[Security Gateway\](eth2) --- \[Server\]* 6. *TCP **ACK*** from \[Client\] will pass through *Pre-Outbound* and *Post-Outbound* on interface **eth2**: *\[Client\] --- (eth1)\[Security Gateway\] {*Pre-Outbound* and *Post-Outbound*} (eth2) --- \[Server\]* Once started, the *FW Monitor* compiles the INSPECT filter (created as *$FWDIR/tmp/monitorfilter.pf* ) based on the specified syntax (which packets to capture), and loads it to the Check Point kernel (not replacing the Security Policy). The *FW Monitor* will then continuously get packets from the Check Point kernel, and depending on the syntax, will either display them on the terminal window, or will save them in the output capture file. Upon an interrupt signal (key combination CTRL + C), the *FW Monitor* stops, unloads the INSPECT filter, and exits. (5) FW Monitor Syntax and Usage {#FW Monitor Syntax and Usage} -------------------------------------------------------------- ### (5-A) FW Monitor Syntax and Usage - Syntax {#FW Monitor Syntax and Usage - Syntax} * For IPv4: **`[Expert@HostName]# fw monitor [-h] [-u|-s] [-i] [-d] [-D] [-t] [{-e <`*expr* `>}+ | -f <`*filter_file_name* `>|-] [-l `*length* `] [-m i|I|o|O] [-x offset[,`*length* `]] [-o <`*output_file_name* `>] <[-pi `*position* `] [-pI `*position* `] [-po `*position* `] [-pO `*position* `] | -p all> [-a] [-ci `*count* `] [-co `*count* `] [-v `*VSID*`] [-w whole packet] [-F ",,,,"] [-U]`** * For IPv6: **`[Expert@HostName]# fw6 monitor [-h] [-u|-s] [-i] [-d] [-D] [-t] [{-e <`*expr* `>}+ | -f <`*filter_file_name* `>|-] [-l `*length* `] [-m i|I|o|O] [-x offset[,`*length* `]] [-o <`*output_file_name* `>] <[-pi `*position* `] [-pI `*position* `] [-po `*position* `] [-pO `*position* `] | -p all> [-a] [-ci `*count* `] [-co `*count* `] [-v `*VSID*`] [-w whole packet] [-F ",,,,"] [-U]`** Enter the string to filter this table: |------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | Flag | Explanation | | `-h` | Displays the usage. | | `-i` | Flushes the standard output. Use this flag to make sure that captured data for each packet is at once written to standard output. This is especially useful if you want to kill a running *FW Monitor* process, and want to be sure that all data is written to a file. | | `-d` `-D` | Starts the *FW Monitor* in the debug mode. This will give you an insight into *FW Monitor's* inner workings, although this option is only rarely used outside Check Point. Use the "*-D*" flag will produce an even more verbose output. | | `-t` | When compiling the INSPECT filter, includes *$FWDIR/lib/tcpip.def*, which allows using TCP/IP macros. **Warning:** Do not modify anything in *$FWDIR/lib/tcpip.def* or in any other *$FWDIR/lib/\*.def* file by yourself. Check Point does not support any configuration with changed *\*.def* files. An exception are modifications done together with Check Point Support (according to a Service Request) or found in SecureKnowldege. | | `{-e <`*expr* `>}+ |` ` -f <`*filter_file_name*`> | -` | **Note:** From version [R80.20 Jumbo Jotfix Accumulator take_73](https://support.checkpoint.com/results/sk/sk137592), the "-e" flag is not supported for Accelerated traffic. Captures only specific packets: * Set the filter expression on the command line using the *-e \<*expr*\>* switch * Read the filter expression from a file using the *-f \<*filter_file_name*\>* switch * Read the filter expression from the standard input using the *-f -* switch **Note:** When using filter expressions on the command line (using "*-e \<*expr*\>* " switch), make sure that the expressions are properly quoted. On Windows and UNIX operating systems, this can be done by surrounding the expression with single quote ***'*** (ASCII value 39), or double quotes *"* (ASCII value 34). Depending on the given operating system and shell, there might be differences between the two forms - especially when using special characters, or (shell) variables in the filter expression. | | `-l `*length* | Limits the length of the captured packets. *FW Monitor* will read only as many bytes from the kernel as specified by the **length**. Make sure to capture as least as many bytes, so that the L3 IP header and L4 Transport header are included. This option allows capturing only the headers of a packet (e.g., IP and TCP), while omitting the actual payload, and thus decreases the size of the output file (by omitting the payload). *FW Monitor* uses a buffer to transfer the packets from Check Point kernel to user space. If the size of the captured packets is reduced, this buffer will not fill up so fast. | | `-m i` `-m I` `-m o` `-m O` `-m e` `-m E` | Capture masks. By default, *FW Monitor* captures packets *before* and *after* the FireWall Virtual Machine in both directions. This flag allows to specify the positions (kernel chains), where the traffic should be captured: * `i` - Pre-Inbound only (before the packet enters a Chain Module in the inbound direction) * `I` - Post-Inbound only (after the packet passes a Chain Module in the inbound direction) * `o` - Pre-Outbound only (before the packet enters a Chain Module in the outbound direction) * `O` - Post-Outbound only (after the packet passes through a Chain Module in the outbound direction) * `e` - Pre-Outbound VPN only (before the packet enters a VPN Chain Module in the outbound direction) * `E` - Post-Outbound VPN only (after the packet passes through a VPN Chain Module in the outbound direction) | | `-x offset[,`*length*`]` | Prints packet/payload raw data in addition to the IP and Transport headers. Optionally it is also possible to limit the data written to the screen. | | `-o <`*output_file_name*`>` | Writes the captured raw data into an output file. The format of an output file is the same format used by tools like snoop (refer to [RFC 1761](https://tools.ietf.org/html/rfc1761) for further information). This output file can be later analyzed by tools like WireShark. | | `-pi `*position* `-pI `*position* `-po `*position* `-pO `*position* `-p all` | Inserts *FW Monitor* chain module at a specific position between Check Point kernel chains. In addition to capture masks (which give the ability to specify a specific position), this flag defines where exactly (in Check Point kernel chains) the packets should be captured. | | `-a` | Uses absolute chain positions (in Check Point kernel chains). This flag changes the chain ID from a relative value (which only makes sense with the matching output from *fw ctl chain* command) to an absolute value. If the captured data is saved into an output file (using the "*-o \<*output_file_name*\>* " switch), one of the fields written into the output file would be the chain position of the *FW Monitor* chain module. Together with a simultaneous execution of "*fw ctl chain* " command you can determine where the packet was captured. Especially when using "*-p all*" switch, you will find the same packet captured multiples times at different chain positions. | | `-ci `*count* `-co `*count* | Captures a specific number of packets. This is especially useful in situations where the FireWall is filtering high amounts of traffic. In such scenarios, *FW Monitor* may bind so many resources (for writing to the console, or to a file) that recognizing the break sequence (CTRL+C) might take very long time. It is possible to use the "*-ci* " and the "*-co* " switches together. *FW Monitor* will stop capturing packets if the number of packets for one of the two counters reaches the specified "*count*". | | `-u | -s` | Prints connection's Universal-Unique-ID (UUID), or connection's Session UUID (SUUID) for every packet. Note that it is only possible to print the UUID or the SUUID - not both. | | `-v `*VSID* | Applies only to VSX NG, VSX NGX, and VSX NGX R6x versions. Captures the packets on a specific Virtual Router or Virtual System on VSX Gateway (Example: *fw monitor -v 4 -e "accept;" -o /var/log/fw_mon.cap*) | | `-w` | When using the "`-o`" or the "`-x`" flag, there is an option to print the whole raw data of a packet. Supported versions: * R80.40 and above * R80.30 Jumbo Hotfix Accumulator Take 215 and above * R80.20 Jumbo Hotfix Accumulator Take 73 and above | | `-F ", , , , "` | Filtering the packets based on IP / port / protocol. **Notes:** * Value 0 is used as "any". * Up to 5 filters are supported. Multiple filters are applied on packets in OR logical manner. Supported versions: * R80.40 and above * R80.30 Jumbo Hotfix Accumulator Take 215 and above * R80.20 Jumbo Hotfix Accumulator Take 73 and above | | `-U` | Unloads the FW Monitor filters. Supported versions: * R80.40 and above * R80.30 Jumbo Hotfix Accumulator Take 215 and above * R80.20 Jumbo Hotfix Accumulator Take 73 and above | {#FwMonParametersTable} ### (5-B) FW Monitor Syntax and Usage - Syntax comparison between TCPdump and FW Monitor {#FW Monitor Syntax and Usage - Comparison with TCPdump} Note: Refer to . Enter the string to filter this table: |--------------------------------------------------------------------|-------------------------------|-------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | Function | Flag in TCPdump | Flag in FW Monitor | Notes | | Save output into a file | **`-w `**** | **`-o `**** | | | Capture specified number of bytes per packet | **`-s `*snaplen*** | **`-l `*length*** | For TCPdump: * If not specified, then 65535 bytes are captured * It is recommended to use "`-s 1500`" * Setting *snaplen* to 0 sets it to the default of 65535 bytes For FW Monitor: * By default, not needed * Refer to the table above | | Automatically exit after specified number of packets was captured | **`-c `*count*** | **`-ci `*count*** **`-co `*count*** | For FW Monitor: * Refer to the table above | | Print payload content | **`-X`** | **`-x `*offset[,length]*** | For TCPdump: * In addition to printing the headers of each packet, prints the data of each packet (minus its Link Level header) in Hex and ASCII For FW Monitor: * Refer to the table above | | Display timestamps on CLI (when not saving output into a file) | **`-tt`** | N/A | For TCPdump: * Prints an unformatted timestamp on each dump line. | | Display timestamps on CLI (when not saving output into a file) | **`-ttt`** | **`-T`** | For TCPdump: * Prints a delta (micro-second resolution) between current and previous line on each dump line. | | Display timestamps on CLI (when not saving output into a file) | **`-ttt`** | N/A | For TCPdump: * Prints a delta (micro-second resolution) between current and previous line on each dump line. | | Display timestamps on CLI (when not saving output into a file) | **`-tttt`** | N/A | For TCPdump: * Prints a timestamp in default format preceeded by date on each dump line. | | Display timestamps on CLI (when not saving output into a file) | **`-ttttt`** | N/A | For TCPdump: * Print a delta (micro-second resolution) between current and first line on each dump line. | | Display verbose output on CLI (when not saving output into a file) | **`-v`** | **`-d`** | For TCPdump: * Produces slightly more verbose output. For example, the TTL, Identification, total length and options in an IP packet are printed. Also enables additional packet integrity checks, such as verifying the IP and ICMP header checksum. For FW Monitor: * Refer to the table above | | Display verbose output on CLI (when not saving output into a file) | **`-vv`** | **`-D`** | For TCPdump: * Produces even more verbose output. For example, additional fields are printed from NFS reply packets, and SMB packets are fully decoded. For FW Monitor: * Refer to the table above | | Display verbose output on CLI (when not saving output into a file) | **`-vvv`** | **`-D`** | For TCPdump: * Produces even more verbose output. For example, telnet *SB ... SE* options are printed in full. With "`-X`", Telnet options are printed in Hex as well. For FW Monitor: * Refer to the table above | {#FwMonTcpDumpTable} ### (5-C) FW Monitor Syntax and Usage - Using the UUID feature {#FW Monitor Syntax and Usage - Using the UUID feature} * **Background** The purpose of the new FW Monitor feature is to use the UUID feature (that was introduced in the NG AI family) to follow connections passing through the FireWall. Following connections through the FireWall is not always a trivial task because often the FireWall modifies information in the original packet. These cases include: * NAT, both Static and Dynamic (Hide) * Security Servers * VPN Encryption In Check Point NG AI version, a Universal-Unique-IDentifier (UUID) was introduced as the basis for the log unification mechanism. A UUID is given to every new connection passing through the FireWall. This way, all packets that belong to the connection can be identified and can later be unified on the Security Management Server. This new infrastructure has given us the ability to enhance the "FW Monitor" utility. The FW Monitor utility is a `tcpdump`/`snoop`-like tool that allows us to monitor packets as they pass through the FireWall. The FW Monitor module registers itself as the first and the last module on the chain, allowing us to see any modifications done by the FireWall on the original packet. With the addition of the UUID field to the FW Monitor, entire connections can be monitored as they pass through the FireWall. * **The UUID feature** The original UUID is an array, composed of 4 unsigned 32-bit integers, in which only the first two integers are relevant: UUID\[0\] is a timestamp. UUID\[1\] is a counter used whenever UUID\[0\] is not unique. UUID\[2\] is the IP address of the local firewall (constant) UUID\[3\] is a process number (currently a constant that can be ignored). The UUID feature can be activated with one of the following switches: * **`-u`** = displays the UUID * **`-s`** = displays the session UUID, meaning, display a single (parent) UUID of complex connections involving data/control connections (such as FTP, H.323, etc.) Since we are pressed for space in the header fields of the captured packet, the original UUID has been manipulated to be 1 unsigned long 32-bit integer. It is currently composed of the 2 least significant bytes of UUID\[1\] (16 bits) attached to the 2 least significant bytes of UUID\[0\] (16 bits). This gives us the following amount of unique IDs: * 2^16^ IDs per second * 2^16^ seconds This UUID is then placed in the last four bytes of the Ethernet MAC Source header field. The new Ethernet header MAC fields are now: * 2 bytes - i/I/o/O * 6 bytes - Interface Name * 4 bytes - UUID In addition, it is possible to redirect the FW Monitor output to an ASCII file instead of saving it in a `tcpdump`/`snoop` format. If this is the case, the 32-bit manipulated UUID is displayed as the first field of each line, followed by the entire UUID array. * **Filtering** When viewing the captured file, it is now possible to view the connection by filtering the file by the UUID. This is done by first opening the captured file, finding a packet that belongs to the connection, and getting the last four bytes of the Source MAC address. Then, convert these four bytes to Decimal format and filter the captured file as follows: `# `[tcpdump](https://linux.die.net/man/8/tcpdump)` -r -e -v -xx "ether[8:4] = 0xHHHH"` `# `[snoop](http://docs.oracle.com/cd/E19253-01/816-5166/6mbb1kqij/index.html)` -i -v -x0 "ether[8:4] = 0xHHHH"` where *HHHH* is the decimal equivalent of the last four bytes of the Source MAC address. * **Debugging** The UUID feature can be debugged by collecting the "`fw ctl debug -m fw + chain conn`" debug. Note: The '`filter`' flag may also provide some information, but produces many irrelevant printouts. * **Notes** * The UUID of the first packet of every new connection before the VM is always 0. * The UUID on encrypted packets is also 0. * When running the UUID feature and redirecting the output to a captured file, only the first 6 bytes of the interface name will be displayed. * The compressed UUID can be similar if taken on two different machines (since the IP address portion of the original UUID was not taken into consideration). In addition, it can also be similar if taken days apart (since the counter portion of the compressed UUID will repeat every 18 hours). (6) SecureClient Syntax {#SecureClient Syntax} ---------------------------------------------- * SecurRemote and SecureClient R56 / R60 uses an abridged version of *FW Monitor* - called ***srfw monitor***: **`%SRDIR%\bin\srfw monitor [-d] [{-e <`*expr* `>}+ | -f <`*filter_file_name* `> | -] [-l `*length* `] [-m i | I | o | O] [-x offset[,`*length* `]] [-o <`*output_file_name*`>]`** Refer to *SecureClient R56 for Mac OS X Release Notes* ([Mac OS X 10.3](http://downloads.checkpoint.com/dc/download.htm?ID=7970), [Mac OS X 10.4](http://downloads.checkpoint.com/dc/download.htm?ID=7973)) and to [*Debugging SecuRemote/SecureClient*](http://downloads.checkpoint.com/dc/download.htm?ID=10545). * Starting in E75.30, SecurRemote and SecureClient uses command line packet monitoring utility (*PacketMon.exe* ) - called ***packetmon***: **`packetmon [-d] [-h] [-t] [-T] [-i] [-I] [-r] [{-e <`*expr* `>}+ | -f <`*filter_file_name* `> | -] [-l `*length* `] [-m i | I | o | O] [-x offset[,`*length* `]] [-o <`*output_file_name*`>] [-ci count] [-co count]`** Refer to *Remote Access Clients for Windows 32/64-bit Administration Guide* ([E75.30](http://downloads.checkpoint.com/dc/download.htm?ID=20401), [E80.41](http://downloads.checkpoint.com/dc/download.htm?ID=23222), [E80.50](http://downloads.checkpoint.com/dc/download.htm?ID=24859)) - Chapter 'Monitoring and Troubleshooting' - Troubleshooting the Firewall - Desktop Firewall Monitoring. (7) Capture Examples of "-e" flag {#Capture Examples} ----------------------------------------------------- Refer to the *$FWDIR/lib/fwmonitor.def* file on the Security Gateway for useful macro definitions. **Note:** The "`-e`" flag is **not** supported to capture accelerated traffic in these versions: * R80.40 and above * R80.30 Jumbo Hotfix Accumulator Take 215 and above * R80.20 Jumbo Hotfix Accumulator Take 73 and above ### (7-A) Capture Examples - Usual Capture {#Capture Examples - Usual} Capture everything, save the data into the file: ***\[Expert@HostName\]# fw monitor -e "accept;" -o /var/log/fw_mon.cap*** ### (7-B) Capture Examples - Host Specific Capture {#Capture Examples - Host Specific} To specify a host, you can use the following expression: * Either use "***host(\)***", which applies to both Source IP address and Destination IP address * Or use specific Source IP address "***src=\*** " and specific Destination IP address "***dst=\***" *Examples*: * Capture everything between host X and host Y: ***\[Expert@HostName\]# fw monitor -e "host(x.x.x.x) and host(y.y.y.y), accept;" -o /var/log/fw_mon.cap*** ***\[Expert@HostName\]# fw monitor -e "((src=x.x.x.x , dst=y.y.y.y) or (src=y.y.y.y , dst=x.x.x.x)), accept;" -o /var/log/fw_mon.cap*** * Capture everything between hosts X,Z and hosts Y,Z on *all* Check Point kernel chains: ***\[Expert@HostName\]# fw monitor -p all -e "((src=x.x.x.x or dst=z.z.z.z) and (src=y.y.y.y or dst=z.z.z.z)), accept ;" -o /var/log/fw_mon.cap*** * Capture everything to/from host X or to/from host Y or to/from host Z: ***\[Expert@HostName\]# fw monitor -e "host(x.x.x.x) or host(y.y.y.y) or host(z.z.z.z), accept;" -o /var/log/fw_mon.cap*** ***\[Expert@HostName\]# fw monitor -e "((src=x.x.x.x or dst=x.x.x.x) or (src=y.y.y.y or dst=y.y.y.y) or (src=z.z.z.z or dst=z.z.z.z)), accept;" -o /var/log/fw_mon.cap*** ### (7-C) Capture Examples - Port-Specific Capture {#Capture Examples - Port Specific} **Note:** Port number in the syntax has to be provided in Decimal format. Refer to ***/etc/services*** file on the machine, or to To specify a port, you can use the following expression: * Either use "***port(\)***", which applies to both Source Port and Destination Port * Or use specific Source Port "***sport=\*** " and specific Destination Port "***dport=\***" * In addition: * For specific *TCP* port, you can use "***tcpport(\)***", which applies to both Source TCP Port and Destination TCP Port * For specific *UDP* port, you can use "***udpport(\)***", which applies to both Source UDP Port and Destination UDP Port *Examples*: * Capture everything to/from port X: ***\[Expert@HostName\]# fw monitor -e "port(x), accept;" -o /var/log/fw_mon.cap*** ***\[Expert@HostName\]# fw monitor -e "(sport=x or dport=x), accept;" -o /var/log/fw_mon.cap*** * Capture everything except port X: ***\[Expert@HostName\]# fw monitor -e "((sport=!x) or (dport=!x)), accept;" -o /var/log/fw_mon.cap*** ***\[Expert@HostName\]# fw monitor -e "not (sport=x or dport=x), accept;" -o /var/log/fw_mon.cap*** * Capture everything except SSH: ***\[Expert@HostName\]# fw monitor -e "((sport!=22) or (dport!=22)), accept;" -o /var/log/fw_mon.cap*** ***\[Expert@HostName\]# fw monitor -e "not (sport=22 or dport=22), accept;" -o /var/log/fw_mon.cap*** ***\[Expert@HostName\]# fw monitor -e "not tcpport(22), accept;" -o /var/log/fw_mon.cap*** * Capture everything to/from host X except SSH: ***\[Expert@HostName\]# fw monitor -e "(host(x.x.x.x) and (sport!=22 or dport!=22)), accept;" -o /var/log/fw_mon.cap*** ***\[Expert@HostName\]# fw monitor -e "((src=x.x.x.x or dst=x.x.x.x) and (not (sport=22 or dport=22))), accept;" -o /var/log/fw_mon.cap*** ***\[Expert@HostName\]# fw monitor -e "(host(x.x.x.x) and not tcpport(22)), accept;" -o /var/log/fw_mon.cap*** * Capture everything except NTP: ***\[Expert@HostName\]# fw monitor -e "not udpport(123), accept;" -o /var/log/fw_mon.cap*** ### (7-D) Capture Examples - Protocol-Specific Capture {#Capture Examples - Protocol Specific} **Note:** Protocol number in the expression has to be provided in Decimal format. Refer to ***/etc/protocols*** file on the machine, or to To specify a protocol, you can use the following expression: * Either use "***ip_p=\***" : *Examples*: * To specify TCP protocol with byte offset, use "***ip_p=6***" * To specify UDP protocol with byte offset, use "***ip_p=11***" * To specify ICMP protocol with byte offset, use "***ip_p=1***" * Or use "***accept \[9:1\]=\***" (This byte offset syntax is described in the "Capture Examples - Bytes Specific Capture" section) : *Examples*: * To specify TCP protocol with byte offset, use "***accept \[9:1\]=6***" * To specify UDP protocol with byte offset, use "***accept \[9:1\]=11***" * To specify ICMP protocol with byte offset, use "***accept \[9:1\]=1***" * In addition, you can explicitly use the following expressions to specify protocols: |-------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------| | Which protocol to specify | On which port(s) traffic will be captured | Expression | | TCP | --- | ***"tcp, accept;"*** | | UDP | --- | ***"udp, accept;"*** | | ICMPv4 | --- | ***"icmp, accept;"*** or ***"icmp4, accept;"*** | | ICMPv6 | --- | ***"icmp6, accept;"*** | | HTTP | TCP 80 | ***"http, accept;"*** | | HTTPS | TCP 443 | ***"https, accept;"*** | | PROXY | TCP 8080 | ***"proxy, accept;"*** | | DNS | UDP 53 | ***"dns, accept;"*** | | IKE | UDP 500 | ***"ike, accept;"*** | | NAT-T | UDP 4500 | ***"natt, accept;"*** | | ESP and IKE | IP proto 50 and UDP 500 | ***"vpn, accept;"*** | | 1. ESP 2. IPsec over UDP 3. IKE 4. NAT-T 5. CRL 6. RDP 7. Tunnel Test 8. Topology 9. L2TP 10. SCV 11. Multi-Portal 12. etc. This captures *all* VPN-related data. | 1. IP proto 50 2. UDP 2746 3. UDP 500 4. UDP 4500 5. TCP 18264 6. UDP 259 7. UDP 18234 8. TCP 264 9. TCP 1701 10. UDP 18233 11. TCP 443 + TCP 444 12. etc. | ***"vpnall, accept;"*** | | Multi-Portal connections | TCP 443 and TCP 444 | ***"multi, accept;"*** | | SSH | TCP 22 | ***"ssh, accept;"*** | | FTP | TCP 20 and TCP 21 | ***"ftp, accept;"*** | | Telnet | TCP 23 | ***"telnet, accept;"*** | | SMTP | TCP 25 | ***"smtp, accept;"*** | | POP3 | TCP 110 | ***"pop3, accept;"*** | *Examples*: * Capture everything on protocol X: ***\[Expert@HostName\]# fw monitor -e "ip_p=X, accept;" -o /var/log/fw_mon.cap*** * Everything on protocol X and port Z on protocol Y: ***\[Expert@HostName\]# fw monitor -e "(ip_p=X) or (ip_p=Y, port(Z)), accept;" -o /var/log/fw_mon.cap*** * Capture everything TCP between host X and host Y: ***\[Expert@HostName\]# fw monitor -e "ip_p=6, host(x.x.x.x) or host(y.y.y.y), accept;" -o /var/log/fw_mon.cap*** ***\[Expert@HostName\]# fw monitor -e "tcp, host(x.x.x.x) or host(y.y.y.y), accept;" -o /var/log/fw_mon.cap*** ***\[Expert@HostName\]# fw monitor -e "accept \[9:1\]=6 , ((src=x.x.x.x , dst=y.y.y.y) or (src=y.y.y.y , dst=x.x.x.x));"*** ***\[Expert@HostName\]# fw monitor -e "ip_p=6, ((src=x.x.x.x , dst=y.y.y.y) or (src=y.y.y.y , dst=x.x.x.x)), accept;" -o /var/log/fw_mon.cap*** ### (7-E) Capture Examples - Protocol Options Specific Capture {#Capture Examples - Protocol Options Specific} **Note:** Refer to the *$FWDIR/lib/tcpip.def* file on the Security Gateway. |--------------------------------------------------------------------------|----------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | Protocol | Expression | Option Description | | [IPv4](http://en.wikipedia.org/wiki/IPv4) | ***ip_src = \*** | Source [IPv4 address](https://en.wikipedia.org/wiki/IPv4_address) of the [IPv4 packet](https://en.wikipedia.org/wiki/IPv4#Header) Example: *fw monitor -e "ip_src = 192.168.22.33, accept;"* | | [IPv4](http://en.wikipedia.org/wiki/IPv4) | ***ip_dst = \*** | Destination [IPv4 address](https://en.wikipedia.org/wiki/IPv4_address) of the [IPv4 packet](https://en.wikipedia.org/wiki/IPv4#Header) Example: *fw monitor -e "ip_dst = 192.168.22.33, accept;"* | | [IPv4](http://en.wikipedia.org/wiki/IPv4) | ***ip_ttl = \*** | [Time To Live](https://en.wikipedia.org/wiki/Time_to_live) of the [IPv4 packet](https://en.wikipedia.org/wiki/IPv4#Header) Example: *fw monitor -e "ip_ttl = 255, accept;"* | | [IPv4](http://en.wikipedia.org/wiki/IPv4) | ***ip_len = \*** | Total Length of the [IPv4 packet](https://en.wikipedia.org/wiki/IPv4#Header) in bytes Example: *fw monitor -e "ip_len = 64, accept;"* | | [IPv4](http://en.wikipedia.org/wiki/IPv4) | ***ip_tos = \*** | [TOS field](https://en.wikipedia.org/wiki/Type_of_service) of the [IPv4 packet](https://en.wikipedia.org/wiki/IPv4#Header) Example: *fw monitor -e "ip_tos = 0, accept;"* | | [IPv4](http://en.wikipedia.org/wiki/IPv4) | ***ip_p = \*** | [IANA Protocol Number](http://www.iana.org/assignments/protocol-numbers/protocol-numbers.xhtml) (either in Dec or in Hex) encapsulated in the [IPv4 packet](https://en.wikipedia.org/wiki/IPv4#Header) Example 1 for TCP: *fw monitor -e "ip_p = 6, accept;"* Example 2 for UDP: *fw monitor -e "ip_p = 17, accept;"* Example 3 for UDP: *fw monitor -e "ip_p = 0x11, accept;"* Example 4 for ICMP: *fw monitor -e "ip_p = 1, accept;"* | | [IPv6](http://en.wikipedia.org/wiki/IPv6) | ***ip_src6p = \*** | Source [IPv6 address](https://en.wikipedia.org/wiki/IPv6_address) of the [IPv6 packet](https://en.wikipedia.org/wiki/IPv6_packet#Fixed_header) | | [IPv6](http://en.wikipedia.org/wiki/IPv6) | ***ip_dst6p = \*** | Destination [IPv6 address](https://en.wikipedia.org/wiki/IPv6_address) of the [IPv6 packet](https://en.wikipedia.org/wiki/IPv6_packet#Fixed_header) | | [IPv6](http://en.wikipedia.org/wiki/IPv6) | ***ip_len6 = \*** | Payload Length of the [IPv6 packet](https://en.wikipedia.org/wiki/IPv6_packet#Fixed_header) in bytes | | [IPv6](http://en.wikipedia.org/wiki/IPv6) | ***ip_ttl6 = \*** | Hop Limit ("Time To Live") of the [IPv6 packet](https://en.wikipedia.org/wiki/IPv6_packet#Fixed_header) | | [IPv6](http://en.wikipedia.org/wiki/IPv6) | ***ip_p6 = \*** | Next Header of the [IPv6 packet](https://en.wikipedia.org/wiki/IPv6_packet#Fixed_header) - encapsulated [IANA Protocol Number](http://www.iana.org/assignments/protocol-numbers/protocol-numbers.xhtml) Example: *fw monitor -e "ip_p6 = 6, accept;"* | | [TCP](http://en.wikipedia.org/wiki/Transmission_Control_Protocol) | ***syn*** | SYN flag is set in [TCP packet](https://en.wikipedia.org/wiki/Transmission_Control_Protocol#TCP_segment_structure) Example: *fw monitor -e "ip_p = 6, syn, accept;"* | | [TCP](http://en.wikipedia.org/wiki/Transmission_Control_Protocol) | ***ack*** | ACK flag is set in [TCP packet](https://en.wikipedia.org/wiki/Transmission_Control_Protocol#TCP_segment_structure) Example: *fw monitor -e "ip_p = 6, ack, accept;"* | | [TCP](http://en.wikipedia.org/wiki/Transmission_Control_Protocol) | ***rst*** | RST flag is set in [TCP packet](https://en.wikipedia.org/wiki/Transmission_Control_Protocol#TCP_segment_structure) Example: *fw monitor -e "ip_p = 6, rst, accept;"* | | [TCP](http://en.wikipedia.org/wiki/Transmission_Control_Protocol) | ***fin*** | FIN flag is set in [TCP packet](https://en.wikipedia.org/wiki/Transmission_Control_Protocol#TCP_segment_structure) Example: *fw monitor -e "ip_p = 6, fin, accept;"* | | [TCP](http://en.wikipedia.org/wiki/Transmission_Control_Protocol) | ***first*** | First packet of TCP connection (i.e., SYN flag is set, but ACK flag is *not* set in [TCP packet](https://en.wikipedia.org/wiki/Transmission_Control_Protocol#TCP_segment_structure)) Example: *fw monitor -e "ip_p = 6, first, accept;"* | | [TCP](http://en.wikipedia.org/wiki/Transmission_Control_Protocol) | ***not_first*** | Not the first packet of TCP connection (i.e., SYN flag is *not* set in [TCP packet](https://en.wikipedia.org/wiki/Transmission_Control_Protocol#TCP_segment_structure)) Example: *fw monitor -e "ip_p = 6, not_first, accept;"* | | [TCP](http://en.wikipedia.org/wiki/Transmission_Control_Protocol) | ***established*** | Established TCP connection (i.e., either ACK flag is set, *or* SYN flag is *not* set in [TCP packet](https://en.wikipedia.org/wiki/Transmission_Control_Protocol#TCP_segment_structure)) Example: *fw monitor -e "ip_p = 6, established, accept;"* | | [TCP](http://en.wikipedia.org/wiki/Transmission_Control_Protocol) | ***last*** | Last packet of TCP connection (i.e., both ACK flag *and* FIN flag are set in [TCP packet](https://en.wikipedia.org/wiki/Transmission_Control_Protocol#TCP_segment_structure)) Example: *fw monitor -e "ip_p = 6, last, accept;"* | | [TCP](http://en.wikipedia.org/wiki/Transmission_Control_Protocol) | ***tcpdone*** | End of TCP connection (i.e., either RST flag is set, *or* FIN flag is set in [TCP packet](https://en.wikipedia.org/wiki/Transmission_Control_Protocol#TCP_segment_structure)) Example: *fw monitor -e "ip_p = 6, tcpdone, accept;"* | | [TCP](http://en.wikipedia.org/wiki/Transmission_Control_Protocol) | ***th_flags = \*** | General way to match the flags inside in [TCP packets](https://en.wikipedia.org/wiki/Transmission_Control_Protocol#TCP_segment_structure): |-------------------|-------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------| | Syntax | Explanation | Example | | *th_flags = 0x2* | SYN flag is set in [TCP packet](https://en.wikipedia.org/wiki/Transmission_Control_Protocol#TCP_segment_structure) | *fw monitor -e "th_flags = 0x2, accept;"* | | *th_flags = 0x10* | ACK flag is set in [TCP packet](https://en.wikipedia.org/wiki/Transmission_Control_Protocol#TCP_segment_structure) | *fw monitor -e "th_flags = 0x10, accept;"* | | *th_flags = 0x8* | PSH flag is set in [TCP packet](https://en.wikipedia.org/wiki/Transmission_Control_Protocol#TCP_segment_structure) | *fw monitor -e "th_flags = 0x8, accept;"* | | *th_flags = 0x1* | FIN flag is set in [TCP packet](https://en.wikipedia.org/wiki/Transmission_Control_Protocol#TCP_segment_structure) | *fw monitor -e "th_flags = 0x1, accept;"* | | *th_flags = 0x4* | RST flag is set in [TCP packet](https://en.wikipedia.org/wiki/Transmission_Control_Protocol#TCP_segment_structure) | *fw monitor -e "th_flags = 0x4, accept;"* | | *th_flags = 0x20* | URG flag is set in [TCP packet](https://en.wikipedia.org/wiki/Transmission_Control_Protocol#TCP_segment_structure) | *fw monitor -e "th_flags = 0x20, accept;"* | | *th_flags = 0x12* | SYN flag (0x2) *and* ACK flag (0x10) are set in [TCP packet](https://en.wikipedia.org/wiki/Transmission_Control_Protocol#TCP_segment_structure) | *fw monitor -e "th_flags = 0x12, accept;"* | | *th_flags = 0x18* | PSH flag (0x8) *and* ACK flag (0x10) are set in [TCP packet](https://en.wikipedia.org/wiki/Transmission_Control_Protocol#TCP_segment_structure) | *fw monitor -e "th_flags = 0x18, accept;"* | | *th_flags = 0x11* | FIN flag (0x1) *and* ACK flag (0x10) are set in [TCP packet](https://en.wikipedia.org/wiki/Transmission_Control_Protocol#TCP_segment_structure) | *fw monitor -e "th_flags = 0x11, accept;"* | | *th_flags = 0x14* | RST flag (0x4) *and* ACK flag (0x10) are set in [TCP packet](https://en.wikipedia.org/wiki/Transmission_Control_Protocol#TCP_segment_structure) | *fw monitor -e "th_flags = 0x14, accept;"* | | | [TCP](http://en.wikipedia.org/wiki/Transmission_Control_Protocol) | ***th_sport = \*** | TCP source port (refer to [IANA Port Number Registry](http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml)) Example: *fw monitor -e "th_sport = 59259, accept;"* | | [TCP](http://en.wikipedia.org/wiki/Transmission_Control_Protocol) | ***th_dport = \*** | TCP destination port (refer to [IANA Port Number Registry](http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml)) Example: *fw monitor -e "th_dport = 22, accept;"* | | [TCP](http://en.wikipedia.org/wiki/Transmission_Control_Protocol) | ***th_seq = \*** | TCP sequence number (either in Dec or in Hex) Example 1: *fw monitor -e "th_seq = 3937833514, accept;"* Example 2: *fw monitor -e "th_seq = 0xeab6922a, accept;"* | | [TCP](http://en.wikipedia.org/wiki/Transmission_Control_Protocol) | ***th_ack = \*** | TCP acknowledged number (either in Dec or in Hex) Example 1: *fw monitor -e "th_ack = 509054325, accept;"* Example 2: *fw monitor -e "th_ack = 0x1e578d75, accept;"* | | [UDP](http://en.wikipedia.org/wiki/User_Datagram_Protocol) | ***uh_sport = \*** | UDP source port (refer to [IANA Port Number Registry](http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml)) Example: *fw monitor -e "uh_sport = 8116, accept;"* | | [UDP](http://en.wikipedia.org/wiki/User_Datagram_Protocol) | ***uh_dport = \*** | UDP destination port (refer to [IANA Port Number Registry](http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml)) Example: *fw monitor -e "uh_dport = 53, accept;"* | | [ICMPv4](http://en.wikipedia.org/wiki/Internet_Control_Message_Protocol) | ***icmp_type = \*** | [ICMPv4 packets](https://en.wikipedia.org/wiki/Internet_Control_Message_Protocol#ICMP_segment_structure) with specified [Type](https://en.wikipedia.org/wiki/Internet_Control_Message_Protocol#Control_messages) Example: *fw monitor -e "icmp_type = 0, accept;"* | | [ICMPv4](http://en.wikipedia.org/wiki/Internet_Control_Message_Protocol) | ***icmp_code = \*** | [ICMPv4 packets](https://en.wikipedia.org/wiki/Internet_Control_Message_Protocol#ICMP_segment_structure) with specified [Code](https://en.wikipedia.org/wiki/Internet_Control_Message_Protocol#Control_messages) Example: *fw monitor -e "icmp_code = 0, accept;"* | | [ICMPv4](http://en.wikipedia.org/wiki/Internet_Control_Message_Protocol) | ***icmp_id = \*** | [ICMPv4 packets](https://en.wikipedia.org/wiki/Internet_Control_Message_Protocol#ICMP_segment_structure) with specified Identifier Example: *fw monitor -e "icmp_id = 20583, accept;"* | | [ICMPv4](http://en.wikipedia.org/wiki/Internet_Control_Message_Protocol) | ***icmp_seq = \*** | [ICMPv4 packets](https://en.wikipedia.org/wiki/Internet_Control_Message_Protocol#ICMP_segment_structure) with specified Sequence number Example: *fw monitor -e "icmp_seq = 1, accept;"* | | [ICMPv4](http://en.wikipedia.org/wiki/Internet_Control_Message_Protocol) | ***echo_req*** | [ICMPv4](https://en.wikipedia.org/wiki/Internet_Control_Message_Protocol#ICMP_segment_structure) [Echo Request](https://en.wikipedia.org/wiki/Ping_(networking_utility)) packets (Type 8, Code 0) Example: *fw monitor -e "echo_req, accept;"* | | [ICMPv4](http://en.wikipedia.org/wiki/Internet_Control_Message_Protocol) | ***echo_reply*** | [ICMPv4](https://en.wikipedia.org/wiki/Internet_Control_Message_Protocol#ICMP_segment_structure) [Echo Reply](https://en.wikipedia.org/wiki/Ping_(networking_utility)) packets (Type 0, Code 0) Example: *fw monitor -e "echo_reply, accept;"* | | [ICMPv4](http://en.wikipedia.org/wiki/Internet_Control_Message_Protocol) | ***ping*** | [ICMPv4](https://en.wikipedia.org/wiki/Internet_Control_Message_Protocol#ICMP_segment_structure) [Echo Request *and* ICMPv4 Echo Reply](https://en.wikipedia.org/wiki/Ping_(networking_utility)) packets Example: *fw monitor -e "ping, accept;"* | | [ICMPv4](http://en.wikipedia.org/wiki/Internet_Control_Message_Protocol) | ***traceroute*** | [Traceroute](https://en.wikipedia.org/wiki/Traceroute) packets as implemented in Unix OS (UDP packets on ports 30000 and greater and with TTL\<30; or ICMP Time exceeded packets) Example: *fw monitor -e "traceroute, accept;"* | | [ICMPv4](http://en.wikipedia.org/wiki/Internet_Control_Message_Protocol) | ***tracert*** | [Traceroute](https://en.wikipedia.org/wiki/Traceroute) packets as implemented in Windows OS (ICMP Request packets with TTL\<30; or ICMP Time exceeded packets) Example: *fw monitor -e "tracert, accept;"* | | [ICMPv4](http://en.wikipedia.org/wiki/Internet_Control_Message_Protocol) | ***icmp_ip_len = \*** | Length of [ICMPv4 packets](https://en.wikipedia.org/wiki/Internet_Control_Message_Protocol#ICMP_segment_structure) Example: *fw monitor -e "icmp_ip_len = 84, accept;"* | | [ICMPv6](http://en.wikipedia.org/wiki/ICMPv6) | ***icmp6_type = \*** | [ICMPv6 packets](https://en.wikipedia.org/wiki/Internet_Control_Message_Protocol_version_6#Packet_format) with specified [Type](https://en.wikipedia.org/wiki/Internet_Control_Message_Protocol_version_6#Types_of_ICMPv6_messages) Example: *fw monitor -e "icmp6_type = 1, accept;"* | | [ICMPv6](http://en.wikipedia.org/wiki/ICMPv6) | ***icmp6_code = \*** | [ICMPv6 packets](https://en.wikipedia.org/wiki/Internet_Control_Message_Protocol_version_6#Packet_format) with specified [Code](https://en.wikipedia.org/wiki/Internet_Control_Message_Protocol_version_6#Types_of_ICMPv6_messages) Example: *fw monitor -e "icmp6_code = 3, accept;"* | ### (7-F) Capture Examples - Byte-Specific Capture {#Capture Examples - Bytes Specific} Simple checks are used to check for a value at a specific offset in the packet: ***\[Expert@HostName\]# fw monitor -e "accept \[ offset : length , order \] relational-operator value;"*** |-----------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | Field | Explanation | | `offset` | Specifies the offset relative to the beginning of the IP packet from where the value should be read. | | `length` | Specifies the number of bytes: * 1 = byte * 2 = word * 4 = dword If length is *not* specified, *FW Monitor* assumes 4 (dword). | | `order` | Specifies the byte order: * `b` = big-endian, or network order * `l` = little-endian, or host order If order is not specified, *FW Monitor* assumes little endian byte order. | | `relational-operator` | Relational operator to express the relation between the packet data and the value: |----------|-----------------------| | *\<* | less than | | *\>* | greater than | | *\<=* | less than or equal to | | *\>=* | greater than | | *=* | equal to | | *is* | equal to | | *!=* | not equal to | | *is not* | not equal to | | | `value` | One of the data types known to INSPECT (e.g., an IP address, or an integer). | : The IP-based protocols are stored in the IP packet as a byte at offset 9: * To filter based on a Protocol encapsulated into IP, use this syntax: ***\[Expert@HostName\]# fw monitor -e "accept \[9:1\]=\;"*** : The Layer 3 IP Addresses are stored in the IP packet as double words at offset 12 (Source address) and at offset 16 (Destination address): * To filter based on a Source IP address, use this syntax: ***\[Expert@HostName\]# fw monitor -e "accept \[12:4,b\]=\;"*** * To filter based on a Destination IP address, use this syntax: ***\[Expert@HostName\]# fw monitor -e "accept \[16:4,b\]=\;"*** : The Layer 4 Ports are stored in the IP packet as a word at offset 20 (Source port) and at offset 22 (Destination port): * To filter based on a Source port, use this syntax: ***\[Expert@HostName\]# fw monitor -e "accept \[20:2,b\]=\;"*** * To filter based on a Destination port, use this syntax: ***\[Expert@HostName\]# fw monitor -e "accept \[22:2,b\]=\;"*** *Examples*: * Capture everything between host X and host Y: ***\[Expert@HostName\]# fw monitor -e "accept ((\[12:4,b\]=x.x.x.x , \[16:4,b\]=y.y.y.y) or (\[12:4,b\]=y.y.y.y , \[16:4,b\]=x.x.x.x));"*** * Capture everything on port X: ***\[Expert@HostName\]# fw monitor -e "accept \[20:2,b\]=x or \[22:2,b\]=x;" -o /var/log/fw_mon.cap*** ### (7-G) Capture Examples - Network-Specific Capture {#Capture Examples - Network Specific} To capture traffic to/from a network, you need to specify the ***network address*** and ***length of network mask*** (number of bits). There are 3 options: |----------------------|--------------------------------------------------------------------| | Traffic direction | Expression | | To or From a network | ***"net(\, \), accept;"*** | | To a network | ***"to_net(\, \), accept;"*** | | From a network | ***"from_net(\, \), accept;"*** | *Examples*: * Capture everything to/from network 192.168.33.0 / 24: ***\[Expert@HostName\]# fw monitor -e "net(192.168.33.0, 24), accept;"*** * Capture everything sent to network 192.168.33.0 / 24: ***\[Expert@HostName\]# fw monitor -e "to_net(192.168.33.0, 24), accept;"*** * Capture everything sent from network 192.168.33.0 / 24: ***\[Expert@HostName\]# fw monitor -e "from_net(192.168.33.0, 24), accept;"*** ### (7-H) Capture Examples - Some Examples {#Capture Examples - Some Examples} * Capture ESP protocol or UDP port 161 (SNMP): ***\[Expert@HostName\]# fw monitor -e "(ip_p=50) or (ip_p=17, port(161)), accept;" -o /var/log/fw_mon.cap \> /dev/null 2\>\&1 \&*** * Filter out the usual garbage (SMTP, POP3, SSH, Microsoft NetBIOS, Check Point ClusterXL CCP): ***\[Expert@HostName\]# fw monitor -e "(sport!=25) and (dport!=25) and (sport!=110) and (dport!=110) and (sport!=22) and (dport!=22) and (sport!=137) and (dport!=137) and (sport!=8116) and (dport!=8116), accept;" -o /var/log/fw_mon.cap \> /dev/null 2\>\&1 \&*** * Filter out the usual garbage (filter in only TCP protocol, and HTTP and HTTPS ports ; filter out the SSH and FW Logs): ***\[Expert@HostName\]# fw monitor -e "accept (ip_p=6) and (not (sport=22 or dport=22)) and (not (sport=257 or dport=257)) and ((dport=80 or dport=443) or (sport=80 or sport=443);" -o /var/log/fw_mon.cap \> /dev/null 2\>\&1 \&*** * Capture Edge communication between 10.10.10.10, or 20.20.20.20, or 30.30.30.30 and on UDP ports 9281, or 9282, or 9283: ***\[Expert@HostName\]# fw monitor -e "ip_p=17, (host(10.10.10.10) or host(20.20.20.20) or host(30.30.30.30)) and (port(9281) or port(9282) or port(9283)), accept;" -o /var/log/fw_mon.cap*** (8) Capture Examples of "-F" flag {#Capture Examples - F} --------------------------------------------------------- ### (8-A) Usual Capture {#Capture Examples - 8 Usual} Capture everything, you can use the following expression: ***-F "0,0,0,0,0"*** ### (8-B) Host-Specific Capture {#Capture Examples - 8 Host Specific} To specify a host, you can use the following expression: ***-F "x.x.x.x,0,y.y.y.y,0,0"*** This will filter for connections with the source IP x.x.x.x and the destination IP y.y.y.y. Protocol number and port numbers can be any value. **Note:** This means the filter will only catch one direction of the connection, so set a second (set of) filter to catch the other direction. Examples: * ***fw monitor -F "x.x.x.x,0,y.y.y.y,0,0"*** This will filter connection "x.x.x.x:\ --\> y.y.y.y:\, \" Source ip: x.x.x.x, source port: any, destination ip: y.y.y.y, destination port: any, protocol: any. * ***fw monitor -F "x.x.x.x,0,y.y.y.y,0,0" -F "y.y.y.y,0,x.x.x.x ,0,0"*** This will filter connection "x.x.x.x:\ --\> y.y.y.y:\, \" or connection " y.y.y.y:\ --\> x.x.x.x:\, \" Filter 1: source ip: x.x.x.x, source port: any, destination ip: y.y.y.y, destination port: any, protocol: any. Filter 2: source ip: y.y.y.y, source port: any, destination ip: x.x.x.x, destination port: any, protocol: any. ### (8-C) Port-Specific Capture {#Capture Examples - 8 Port Specific} To specify ports numbers, you can use the following expression: ***-F "0,x,0,y,0"*** This will filter connection with source port x and destination port y. Protocol number and ip's can be any value. Examples: * ***fw monitor -F "0,x,0,y,0"*** This will filter connection "\:x --\>\:y, \" Source ip: any, source port: x, destination ip: any, destination port: y, protocol: any. * ***fw monitor -F "x.x.x.x,z,y.y.y.y,0,0" -F "y.y.y.y,0, x.x.x.x ,z ,0"*** This will filter connection "x.x.x.x:z --\> y.y.y.y:\, \" or connection " y.y.y.y:\ --\> x.x.x.x:z, \" Filter 1: source ip: x.x.x.x, source port: z, destination ip: y.y.y.y, destination port: any, protocol: any. Filter 2: source ip: y.y.y.y, source port: any, destination ip: x.x.x.x, destination port: z, protocol: any. ### (8-D) Protocol-Specific Capture {#Capture Examples - 8 Protocol Specific} To specify a protocol number, you can use the following expression: ***-F "0,0,0,0,x"*** This will filter for connections with the protocol number "X". Port number and IP addresses can be any value. Examples: * ***fw monitor -F "0,0,0,0,x"*** This will filter connection "\:\ --\> \:\, \" Source ip: any, source port: any, destination ip: any, destination port: any, protocol: x. For example, to capture the GRE traffic (protocol 47): *fw monitor -F "0,0,0,0,47"* * ***fw monitor -F "x.x.x.x,0,y.y.y.y,z,m" -F "y.y.y.y,z, x.x.x.x ,0,m"*** This will filter connection "x.x.x.x:\ --\> y.y.y.y:z, \" or connection " y.y.y.y:z --\> x.x.x.x:\, \" Filter 1: source ip: x.x.x.x, source port: any, destination ip: y.y.y.y, destination port: z, protocol: m. Filter 2: source ip: y.y.y.y, source port: z, destination ip: x.x.x.x, destination port: any, protocol: m. (9) Related Documentation {#Related Documentation} -------------------------------------------------- * [Security Gateway Guide](https://support.checkpoint.com/product/73#f-commonsource=C.%20Documentation) (10) Related Solutions {#Related Solutions} ------------------------------------------- * [sk101878 - CPView Utility](https://support.checkpoint.com/results/sk/sk101878) * [sk141412 - cppcap - A Check Point Traffic Capture Tooly](https://support.checkpoint.com/results/sk/sk141412) * [sk43076 - How to work with large traffic capture files](https://support.checkpoint.com/results/sk/sk43076) * [sk39510 - How to configure Wireshark to show Check Point FireWall chains in an FW Monitor packet](https://support.checkpoint.com/results/sk/sk39510) * [sk52421 - Ports used by Check Point software](https://support.checkpoint.com/results/sk/sk52421)

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