techblog 

There has been recent instability in one of the LANs that is run by the London Internet Exchange (LINX). Thanks to their hard work the network is now stable again, but this RIPE NCC DNSMON plot shows that some of our nameservers were affected.

The nameservers worst affected were all within the UK. ns6.nic.uk is in Amsterdam, ns[a-d].nic.uk are anycasted by Neustar from locations around the world.

ns1.nic.uk is hosted by LINX themselves, so it is unsurprising that this box was worst affected. The other servers show how much connectivity relies on peering agreements, to a greater or lesser degree. ns3.nic.uk is hosted by Telecity, and was much less affected. It is interesting that ns7.nic.uk, which is in Manchester, suffered quite badly. I guess this because most traffic heading for Manchester is going through London.

An instability within the Dutch internet exchange, AMS-IX is also visible in a DNSMON plot. Here, the Amsterdam node was worst affected.

No name resolution problems were reported to us during either of these outages. I would like to claim credit for running a resilient and diverse nameserver network, but DNS itself can cope with these network issues.