> Source: [sk185044](https://support.checkpoint.com/results/sk/sk185044)

# sk185044 - Clish displays (null) MAC address for specific IPv4 ARP entries

| Property | Value |
|----------|-------|
| Solution ID | sk185044 |
| Date Created | 2026-06-09 |
| Last Modified | 2026-09-10 |
| Technical Level | General |
| Products | Security Gateway |
| Versions | R82.10, R82 |
| OS | Gaia |

## Symptoms

- * In Clish on the Security Gateway, the command: `show arp dynamic all` displays some IPv4 entries with the MAC address shown as "(null)".
* In Expert mode on the Security Gateway, the command: `arp -an | grep IP_address` shows the same ARP entries with a valid MAC address.
* The discrepancy between Clish and Expert mode is observed for specific IP addresses.
* The issue occurs when the IPv4 address contains four three-digit octets (for example, 192.168.151.181).
* The behavior may persist after a reboot of the Security Gateway.
* The behavior may reoccur intermittently.

## Cause

This behavior occurs due to a software condition in Clish when processing IPv4 ARP entries with a dotted?decimal representation of 15 characters (four three?digit octets).

Under this condition, the Clish output parser may misalign fields in the presentation layer. As a result, the MAC address field is interpreted as empty and displayed as "(null)", even though the ARP entry exists correctly in the system kernel.

## Solution

This problem was fixed. The fix is included in:

* [Jumbo Hotfix Accumulator for R82.10](https://sc1.checkpoint.com/documents/Jumbo_HFA/R82.10/Default.htm) starting from Take 44
* [Jumbo Hotfix Accumulator for R82](https://sc1.checkpoint.com/documents/Jumbo_HFA/R82/Default.htm) starting from Take 126

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://support.checkpoint.com/results/sk/sk168597).

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