[Openvpn-users] DNS Round-robin-records vs. "Preserving recently used remote address"

[Ralf H. <Ral...@ch...>]

Hi!

We're using DNS Round-robin-records with a TTL of 300s for our openvpn
endpoint servers.

Yet, clients seem to reconnect to the same IP, although the DNS entry
has expired; the log usually shows something like:

2024-02-21 11:37:04 TCP/UDP: Preserving recently used remote address: [AF_INET]193.175.73.xxx:1194

Yes, it makes perfect sense to re-use a known IP, especially in the
VPN context (DNS settings might just be off while dropping out of the
VPN etc.), but this does really clash with our intentionally low TTL -
at least when we're removeing one endpoint from the DNS for maintenance.

-- 
Ralf Hildebrandt
Charité - Universitätsmedizin Berlin
Geschäftsbereich IT | Abteilung Netz | Netzwerk-Administration
Invalidenstraße 120/121 | D-10115 Berlin

Tel. +49 30 450 570 155
ral...@ch...
https://www.charite.de