> Source: [sk42182](https://support.checkpoint.com/results/sk/sk42182)

# sk42182 - How to modify the ARP cache timeout value

| Property | Value |
|----------|-------|
| Solution ID | sk42182 |
| Date Created | 2009-06-26 |
| Last Modified | 2020-08-31 |
| Technical Level | General |
| Products | Security Gateway |
| Versions | R82.10, R82, R81.20 |
| OS | Linux |

## Solution

**In Gaia, the user should run in Clish: *set arp table validity-timeout \<60-86400\>*.**

**Or via the webUI:**   

[![](https://sc1.checkpoint.com/sc/SolutionsStatics/sk42182/sk421821710310509.png)](../SolutionsStatics/sk42182/sk421821710310509.png)

*** ** * ** ***

**In Non-Gaia (Linux) systems:**

Each interface will have its own value set by the default value upon boot.  

To read the current value: `sysctl -a | grep gc_stale_time`  
To set the current value on-the-fly: `sysctl -w net.ipv4.neigh.`*<interface>* `.gc_stale_time=`*<value>*  

It is strongly recommend to set all interfaces to the same value.  

To change the value permanently `/etc/sysctl.conf` must be modified.

* The default value applied to all interfaces upon boot:   
  `net.ipv4.neigh.default.gc_stale_time = <value>`
* Per interface:  
  `net.ipv4.neigh.`*<interface>* `.gc_stale_time = `*<value>*

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