DNS, nslookup and ping -n slow, sometimes.
Posted on 2008-11-05
I have one server running win2003 r2. It is the single AD and DNS a small network or 10 PC's. It was done for central administration of these machines but im not so sure that was a smart move anymore.
This server has 2 nics, I have one configured for the small network (10.x.x.x)with the dns setting pointing to itself, this DNS server is forwarded to out corporate DNS server.
The other nic on this machine is configured for the larger more public (192.x.x.x intranet) lan segment, but not plugged into anything yet. Its purpose will be more public (i.e. browser based) IIS presentation of information taken from the other, more locked down segment.
There are 2 other servers so far and they are just servers, no dns nothing else, they run a program that must be run on server platform. these both have 2 nics also, one 10.x.x.x and the other 11.x.x.x. The 11.x.x.x is a fiber nic that only goes to the other server, it is used exclusively for these two machine to sync their proprietary databases to each other.
The problem I am having is name resolution is slow, sometimes. I can sometimes ping and get <1ms response and everything is snappy and quick. Other times I get <44ms response and I have name resolution and general sluggish performance problems.
I can't locate any thing that would be variable in this way. I have the 2 servers pointing to the main server for DNS, the main server points to itself for DNS, and that DNS uses a forwarder. web browsing works.
This is intermittent but frequent.
All I can imagine is that the double NICs are somehow confounding this situation. But I am out of ideas. IS it possible that teh 2 servers are somehow sending DNS through the fiber link to each other and it's not getting out? Would someone give me some
tests to run that can help locate the issue?
BTW all IP's are static so I could use a host file but since I can ping-n and get delayed results as well, I don't think that would fix this.