> Source: [sk173978](https://support.checkpoint.com/results/sk/sk173978)

# sk173978 - IPv6  NDP does not work after enabling it

| Property | Value |
|----------|-------|
| Solution ID | sk173978 |
| Date Created | 2021-06-12 |
| Last Modified | 2025-09-29 |
| Technical Level | Advanced |
| Products | Security Gateway |
| Versions | R81.20, R81.10 (EOS), R81 (EOS) |
| OS | Gaia |

## Symptoms

- * IPv6 Neighbor Discovery Protocol (NDP) does not work on Gaia Kernel version 3.10 and above.
* After users follow [sk91905](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk91905), IPv6 still does not work.
* Interface configurations and other configurations are correct.

## Cause

The proxy ndp is NOT enabled on the Linux level in Linux kernel 3.10 and above.  

In kernel 3.10, the value of the file */proc/sys/net/ipv6/conf/\<interface\>/proxy_ndp* is 0 by default, which means disabled.  

In kernel 2.6, there is no proxy ndp enabling file. The proxy ndp is enabled by default.

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## Solution

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