> Source: [sk173933](https://support.checkpoint.com/results/sk/sk173933)

# sk173933 - No ARP request when an ICMP request is sent through the Security Gateway

| Property | Value |
|----------|-------|
| Solution ID | sk173933 |
| Date Created | 2021-06-14 |
| Last Modified | 2021-11-02 |
| Technical Level | General |
| Products | Security Gateway |
| Versions | R81 (EOS) |
| OS | Gaia |

## Symptoms

- * The Security Gateway does not send an ARP request when the ICMP request is sent.

* There is no ICMP reply when pinging through the Security Gateway.

* The ICMP reply is received only from the second or third request.

* In FW Monitor, the ICMP request enters the Security Gateway, passing the little "i", passing the big "I," and disappearing.

## Cause

The affected versions are:

* R80.40 Jumbo Hotfix Take 94 and higher
* R81 Jumbo Hotfix Take 23

Only Security Gateways in **kernel mode** are affected.   

To check if a Security Gateway is in kernel mode, run the commands below in expert mode:

1. `# cpprod_util FwIsUsermode `
2. `# cpprod_util FwIsUsfwMachine `

If the output is `1`, the Security Gateway is User-Space Firewall (USFW). If the output is `0`, the Security Gateway is in Kernel mode.

## Solution

This problem was fixed. The fix is included starting from:

* [Check Point R81.10](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk170416)
* [Jumbo Hotfix Accumulator for R81](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk170114) starting from Take 42
* [Jumbo Hotfix Accumulator for R80.40](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk165456) starting from Take 119

If you choose not to upgrade, Check Point can supply a **Hotfix** . [Contact Check Point Support](https://www.checkpoint.com/support-services/contact-support/) to get a Hotfix for this issue.  
A Support Engineer will make sure the Hotfix is compatible with your environment before providing the Hotfix.  
For faster resolution and verification, please collect [CPinfo files](http://supportcontent.checkpoint.com/solutions?id=sk92739) from the Security Management Server and Security Gateways involved in the case.

**Hotfix installation instructions:**   
Refer to [sk168597 - How to install a Hotfix](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk168597).

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