i do pingtest for 4 different ips (2 for google and yahoo website and 2 for DNS servers; google DNS & open DNS). Yesterday my primary connection went down and it didn’t failover to the secondary WAN (for more than 5 minutes: i had to disconnect the connection manually and reconnect).
I am using priority algotithm (with 2 sec timeout, 5 sec interval, 1 retry). when internet went down it was pinging ok for 2 websites(google & yahoo website), but it wasn’t pinging for google DNS and open DNS. Of course i put those two DNS servers in the settings.
Can anyone think what happened? I don’t think it is possible for google DNS and open DNS go down at the same time.
One more question is that if DNS1 goes down, DNS2 kicks in automatically? if it does, how long does it take for DNS server to be switched over?