Wireguard, DDNS, no connection after server ISP IP changed

[ZebraOnPC]

both client and server on OpenWrt 19.7.8

Server has external dinamic IP it changes onece in 3 -20 days DDNS (noip.com) is working
Client has external static IP it never changes

I have noticed a problem:
When my server ISP changes IP i cant ping or connect to client unless i restart client WG interface. DDNS server updates IP correctly.
If i ping my server adress from client it responce with correct adress but still cant connect untill I restart client WG interface.
keep alive on server 37 seconds
kep alive on client 25 seconds

[psherman]

Just a guess… from your description, it seems like wireguard does dns resolution once and then sticks with that resolved ip until you restart the interface. If that is the case, you could setup a watchdog script that looks for a change in the ip (and/or a failure of the wg tunnel) and then bounces the interface.

[ZebraOnPC]

yes i looks like it
i just thought maybe there is some good solution without making any scripts like some parametrs in wire guard

[pavelgl]

Wireguard problem with resolving peer

There is a "wireguard-watchdog" script exactly for that purpose. It is part of wireguard-tools, usage is described in the commit message. Called via a cronjob (documentation recommends every minute) it checks all wireguard connections for their last handshake, and if it is more than 150 seconds in the past, re-initializes the respective connection ... which also includes a new lookup. (And I can personally attest that it works perfectly.) While this would work, it is a rather blunt instrume…