lost connection on dynamic IP

[Max Schulze]

On 20.05.21 18:20, Roman Mamedov wrote:
> On Thu, 20 May 2021 11:15:30 +0500
> Roman Mamedov <rm at romanrm.net> wrote:
>
>>> So, what do you mean is that wireguard does a single DNS resolution at
>>> the beginning and further DNS resolutions need to be done elsewere. Is
>>> that correct?
>> Yes.
> I also remembered a case where just PersistentKeepalive won't save you, and
> periodic DNS resolution on clients becomes mandatory. It is when the server's
> physical location gets a power cut. On new boot-up (and router power-on) it
> gets a new IP from the ISP, and has no idea where all the clients are. The
> communication is broken until clients recheck the DNS record and update the
> server's endpoint from that. WG does not do this on its own.
>

Just to point out what 'others are doing' - openwrt has a watchdog 
script [1] that might be run with cron every 15 mins


*/15 * * * * /usr/bin/wireguard_watchdog


which will update the new endpoint if the last handshake is too old:

wg set ${iface} peer ${public_key} endpoint 
"${endpoint_host}:${endpoint_port}"


It needs PersistenKeepalive also, if i understand correctly.

[1] 
https://git.openwrt.org/?p=openwrt/openwrt.git;a=blob;f=package/network/utils/wireguard-tools/files/wireguard_watchdog;hb=HEAD


--

Max