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Occasionally our LAN stops resolving host names. We have no idea why this happens. How can we diagnose these issues?

We have two routers. One is connected to the internet (via a fiber modem). The other one is set up as a wireless switch. i.e. it serves the internet via the first router, but it is in a different room and is used for Ethernet connections to computers in that room.

The issue seems to stem from the first router (or something else). I doubt its the switch router, or any issue with config across the network. This is because we usually type http://home to get to the router config for the internet connected router, but this isn't working. However, we can type in the IP address and get to the config page. This happens whether we are connected to the original or the switch router.

Similarly we have a web server on the lan which we normally use the hostname of the computer to access, which we cannot do over the network (again the ip address works though).

Similarly pinging the IP addresses on the network works, but host names don't.

I am not aware how we fix this, if at all. We normally restart the routers and such and they come back. This time they haven't though, so I am looking for a little more insight as to why this may be happening.

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what is the model of the two routers? – Logman Jun 1 '12 at 16:21
Is this a Windows or Linux environment? Are you using an internal DNS server? – jmreicha Jun 1 '12 at 20:18
The first router is a 2wire bt home hub router, the second is a netgear router. I appologise, I am now away from work and cannot find model numbers. The server is linux, plus is running a windows 7 vm which won't resolve either. We also have a netgear NAS box, various windows computers and various Mac computers connecting to the network. None will resolve and none can resolve other host names... :/ Thanks guys. – Thomas Clayson Jun 1 '12 at 21:39
Where is name resolution supposed to happen? On the linux server? – Mike Pennington Jun 3 '12 at 21:59
Nope... over the router I guess. It has its own DNS server. – Thomas Clayson Jun 6 '12 at 9:29

If the LAN doesn't have too many computers, and/or doesn't depend on internal DNS routes, set the DNS parameters in pv4 configuration to:


This will give the DNS resolving work to google's servers.

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