We have seen intermittent problems over the last week or so, where VM's DNS server is not finding things it should - stable DNS entries, not new ones that would not yet have propagated. The effect is Safari saying servers weren't found - and a few mins later if we refresh the window, they appear OK.
Here is an example. On this occasion, 184.108.40.206 reports SERVFAIL:
Welcome to our forum, I am sorry you are having intermittent problems resolving on our DNS. I have had a chat with our engineers about it and the SERVFAIL message usually signifies that we didn’t have the record in our cache, sometimes we have problems getting the latest update from the servers from the domain, in the example you gave us the TTL is only 5 minutes and so this may need to happen quite frequently, is there a reason it is that low by the way.
We were unable to find a problem or reproduce it but will certainly keep an eye on things.
I have again encountered a situation where a site is listed correctly in all other DNS providers I've tried, but not in VM's DNS or fallback DNS. Effectively this renders a website (or company) unreachable for all VM customers.
I wonder if something is going wrong with DNS replication on VM's servers?
In this case it's dpd.co.uk (one of the UK's main courier firms) and on VM I get this (in response to "dig dpd.co.uk" on a Mac console) after a 5 second delay:
Been having the exact same problem today. unable to connect to dpd.co.uk to track a parcel I was expecting.
if I add the ip address
220.127.116.11 into the address bar it connects first time
if I use google dns 18.104.22.168 it works first time
Sp0's dns server looks like its number 53 haven't a clue what mine is I don't have dig installed on this machine
talking to second line is like the most frustrating exercise ever as nobody seems to know what a dns server does. suggestions such as dpd are blocking you are meaningless as it translates the ip address just not the long domain name. Just because it works for them doesn't mean it works on every dns server on the network.
It is a Virgin issue that has nothing to do with my 3rd party equipment as I can connect via every other dns service.
DPD have not blocked any virgin media customers
I suggest there is a corrupt line in #53 dns server and possible others too
First noticed this around 1200 today now 2200 and still there
FYI: 53 is not the number of a DNS server, it's a port number - all calls to DNS use this port. And if you are on Windows you can use NSLOOKUP to check what is being retrieved from your DNS servers.
That particular site seems now to be in Virgin Media's DNS again (24 hours later). However I do think there are intermittent problems with updates not finding their way into VM's DNSes, when other major DNSes receive the updates satisfactorily.
Above all I wonder whether VM's DNSes are monitored with the close attention that is so critical for all of VM's customers. And whether there is am appropriately speedy route for problem reporting and escalation.
When a business disappears from the DNS, locking out all of VM's customers nationwide, that can have a significant economic impact for the business and/or VM's customers.