VPN Causes DNS Failures
(I have an er605 in which I have 2 Wan and 2 lan.
Lan 1: Everything by default
Lan 2: On this lan I have VPN(OPENVPN) that spans all Vlan
The omada server is on lan 1)
I have observed that DNS 8.8.8.8 sometimes responds and sometimes does not.
Because of this, perform ping and traceroute from different points on the network
Ping and traceroute from lan 1: pings respond (30ms on average) and traceroute seems to be all ok. But sometimes it stops responding on the entire LAN leaving devices that use said DNS offline
Ping and traceroute from OMADA (Network Check): *here it gets fun* The ping gives me an average of 250ms and when measuring the tarceroute I realize that it gives me that latency because the DNS 8.8.8.8 is jumping through the lan 2 vpn. Only that DNS jumps to the LAN 2 VPN, I do the ping and traceroute but DNS 8.8.4.4 gives me everything correct and without jumping to the LAN 2 VPN
Ping and traceroute from the terminal: I ping at 8.8.8.8 and it comes out 100% packet loss and the tracert only jumps at 169.254.11.21 and there it stays
Who is to blame for all these failures?
-------The VPN------
The vpn assigns me 2 dns, the first is the vpn gateway and the 2 is 8.8.8.8
When the VPN assigns me 8.8.8.8, it is seen that the ER605 begins to have failures with said DNS
The last thing was to ping -t and see how it came out since 8.8.8.8 could not be accessed and the moment I turned off the vpn of lan 2 the dns 8.8.8.8 began to respond correctly at all points. I turned the VPN back on and the fault came back
(I think this bug could also affect the DNS cache since the router would not be able to access the DNS 8.8.8.8 the DNS cache would also fall)
I clarify that I have not verified the latter but it fits very well with failures that I have had with the DNS cache*