How often are FQDN aliases resolved?

S_D

Hi there,

Should be quite an easy one this. According to the GUI, alias FQDNs are resolved "periodically".

Two questions I have of the back of that, as I'm using an alias to an FQDN that can and does change fairly regularly

How often is 'periodically'?
Does it resolve the FQDN even when the rule it's being used in is not getting hit?

TIA!

Simon

phil.davis

/home/admin.phil: ps aux | grep filter
root       66777   0.0  0.1  16812  2312  -  Ss   Sun08AM    1:24.56 /usr/local/sbin/filterlog -i pflog0 -p /var/run/filterlog.pid
root       72989   0.0  0.3  46136  5608  -  Is   Sun08AM    0:09.27 /usr/local/sbin/filterdns -p /var/run/filterdns.pid -i 300 -c /var/etc/filterdns.conf -
root       66297   0.0  0.1  18884  2376  0  S+    2:47PM    0:00.00 grep filter

Every 300 seconds = 5 minutes
Look in /var/etc/filterdns.conf to see what names it is checking.

S_D

Perfect! Thanks very much.

jimp

You can set the interval yourself under System > Advanced, Firewall/NAT tab. There's a box near the bottom to set the resolve interval.

It defaults to 5 minutes (300 s) but if you only have a handful of hosts, 30 seconds is much more convenient.

The only danger to lowering it is a higher amount of DNS query traffic. So if you have a LOT of hostnames it can easily flood the DNS server with queries if set too low.