Talk-talk Ip addresses 88.109.59.XX (in the old Tiscali range) have their PTR reverse records maintained by:
% host -t ns 59.109.88.in-addr.arpa.
59.109.88.in-addr.arpa nameserver ns0.as9105.com.
59.109.88.in-addr.arpa name server ns0.tiscali.co.uk.
These resolve to 188.8.131.52 and 184.108.40.206 respectfully.
The former is timing out on reverse lookups, and the latter seems to be dead completely.
This is causing connection delays and timeouts when connecting to services that validate connecting IP.
% host 220.127.116.11 18.104.22.168
Using domain server:
Host 22.214.171.124.in-addr.arpa not found: 2 (SERVFAIL)
Please fix ASAP - You should never have SERVFAIL in response to a dns request - it can cause all sorts of problems.
Apologies for the delay, I was meaning to reply but completely forgot. Our Network team did look into this and confirmed that it had actually already been resolved at that point.
Hi Chris. Thanks for getting back to me. I didn't actually notice because I ended up recycling my connection until I got given an IP adress not in the old Tiscali range.
Checking now, yes, it's working, but even so, one of the two registered nameservers for those IP addresses is not working, so there is only one server running, which means problems could easily occur again.
By comparison, your other IP address ranges are served by 3 nameservers, and all 3 are working fine.
If it happens again, users may experience slower connections and connection timeouts (due to those sites that look up reverse DNS on connect) - and the reason may not be so obvious.
It's fine for an IP to have no registered reverse DNS, but when it has one, it should always work (hence why the other IP addresses are configured to be served by 3 servers - all of which are curently working:
% host -t ns 183.21.92.in-addr.arpa.
183.21.92.in-addr.arpa nameserver ds0.opaltelecom.net.
183.21.92.in-addr.arpa nameserver ds1.opaltelecom.net.
183.21.92.in-addr.arpa nameserver ds2.opaltelecom.net.
So, moving forward, I hope the old tiscali nameservers are upgraded appropriately.