> Source: [sk92436](https://support.checkpoint.com/results/sk/sk92436)

# sk92436 - 'DHCPINFORM from X.X.X.X via ethN: not authoritative for subnet X.X.X.X' appears in /var/log/messages file after configuring DHCP Server in Gaia

| Property | Value |
|----------|-------|
| Solution ID | sk92436 |
| Date Created | 2013-02-27 |
| Last Modified | 2022-07-28 |
| Technical Level | General |
| Products | Security Gateway, Security Management Server, Multi-Domain Security Management Server |
| Versions | R82.10, R82, R81.20, R82.20 |
| OS | Gaia |

## Symptoms

- '`DHCPINFORM from `*X.X.X.X*` via eth`*N* `: not authoritative for subnet `*X.X.X.X*' appears in `/var/log/messages` file after configuring DHCP Server in Gaia

## Cause

This is not specific to Check Point Software. This is a global DHCP message ([manual page](http://www.ipamworldwide.com/ipam/dhcp-server-params.html)).

**authoritative** - this parameter indicates that the DHCP server is configured with accurate and authoritative network information in total if defined at the top of the configuration file or within the subnets it is declared. Thus if a client requests a lease for an address for which the server is authoritative yet the server has no record of it the server will respond with DHCPNAK indicating that the client should no longer use the address. This parameter was created to eliminate the issue of an inexperienced administrator turning on a DHCP server and NAK'ing legitimate clients; this would not happen unless the administrator defined the *authoritative* parameter in the configuration file. To explicitly denote non-authority within a scope use the not *authoritative* parameter. This parameter may be set per scope.

## Solution

**Procedure:**

1. Backup the current `/etc/dhcpd.conf` file:   

   **`[Expert@HostName]# cp /etc/dhcpd.conf /etc/dhcpd.conf_ORIGINAL`**   

2. Add new line into the current `/etc/dhcpd.conf` file:   

   **`authoritative;`**   

3. Save the modified `/etc/dhcpd.conf` file.   

4. Restart the DHCPD service:   

   From Expert mode, run these commands:

   **`# tellpm process:dhcpd`**

   **`# tellpm process:dhcpd t`**

**Important Note:**

This file is overwritten during any change in DHCP Server configuration:

* In Gaia Portal - when changing settings on '*Network Management* ' pane - on '*DHCP Server* ' page.  

* In Gaia Clish - when running '*set dhcp server ...*' commands.

In order for this change to survive reboot:

1. Edit the */etc/dhcpd.private* file:

   **`[Expert@HostName]# vi /etc/dhcpd.private`**   

2. Add the following directive:

   **`authoritative;`**   

3. Save the changes in the file and exit from Vi editor.

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