> Source: [sk120122](https://support.checkpoint.com/results/sk/sk120122)

# sk120122 - MTU on VPN traffic is limited by MTU of 1500 even in an environment where jumbo frames are used.

| Property | Value |
|----------|-------|
| Solution ID | sk120122 |
| Date Created | 2017-08-20 |
| Last Modified | 2021-04-29 |
| Technical Level | General |
| Products | Security Gateway |
| Versions | R81.10 (EOS), R81 (EOS) |

## Symptoms

- MTU on VPN traffic is limited by MTU of 1500 even in an environment where jumbo frames are used.

## Solution

[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](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk92739) files from the Security Management and Security Gateways involved in the case.  

**After hotfix is installed, set kernel parameter: *fw ctl set int vpn_default_mtu 9000***

To set the desired value for this kernel parameter permanently follow [sk26202 - Changing the kernel global parameters for Check Point Security Gateway](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk26202).

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