VyOS 1.4.2

After restarting the NHRP service on the Hub, all connected spokes fail to register. The following error messages are observed:

Hub Log: Peer registration failed: static entry exists

Spoke Log: administratively prohibited

Steps to Reproduce:

Set up a DMVPN topology (1 Hub, multiple Spokes) using NHRP.

Ensure everything is functioning normally.

Restart the NHRP service (or reboot) on the Hub.

Check spoke registration — all fail with the above errors.

Suspected Root Cause:
It appears that OpenNHRP is still relying on the legacy routing cache mechanism, which has been removed from the Linux kernel since version 3.6. Upon service restart, OpenNHRP tries to preload local routes, resulting in conflicts that block new peer registrations.

Example Logs:

lua
複製
編輯
Adding local-route x.x.x.1/32 dev tun0
Adding local-route x.x.x.2/32 dev tun0
Additional Symptoms:

Restarting a Spoke may also fail.

Spoke-to-spoke tunnels cannot establish.

Reference:
Similar report on VyOS forum:
https://forum.vyos.io/t/dmvpn-hub-stops-registering-peers-after-any-nhrp-configuration-modification/10875

Expected Behaviour:

Restarting the Hub NHRP service should not block new spoke registrations.

OpenNHRP should not depend on the deprecated routing cache mechanism.