PCs on IP range very slow login

[Theldron]

Hi all,

 

We moved from CC3 to Vanilla over the summer and an external company (i wont mention names) setup AD, DHCP and DNS and I did the rest. We run Ip addresses over x.x.44.x and x.x.45.x. Whilst using Spiceworks I noticed x.x.45.x PCs weren't scanning, so after checking everything else I thought I would check DNS. DNS forward lookup zones all fine, checked the reverse lookup zones and I noticed that only the x.x.44 range folder was in there, so I created the x.x.45 range folder and bipadebopadeeboop the ip addresses suddenly appeared and rescanning Spiceworks all PCs are scanned fine.

 

But I am still noticing that the PCs with x.x.45.x ip addresses are still logging on very slowly compared to the PCs on the other IP range. Is there something else I need to do to DNS for this range?

 

Any help would be greatly appreciated.

 

Cheers

[Gardinho]

If you go to a machine in the 45 range and tracert to a server in the 44 range, does it go via your default gateway address or does it go straight to the server? If so, it is a routing issue and needs to be resolved by whoever manages your router.

[Michael]

Have you tried stopping and restarting DNS Server? Are you operating any VLANs?

[Theldron]

Hey, thanks for the quick reply. On a 44 range machine it went straight to the server when I tracert to the server DNS name and IP address. On the 45 range machine I tracert to the server using the server ip address it went straight to it, but when I tracert to the server using the dns name it goes to the gateway and to other places before it starts to timeout I stopped the tracert after about 16 hops.

[Theldron]

Hi Michael,

 

Thanks for the reply.

 

We are not operating any VLANs and I have restarted DNS.

 

Cheers

[Gardinho]

Hey, thanks for the quick reply. On a 44 range machine it went straight to the server when I tracert to the server DNS name and IP address. On the 45 range machine I tracert to the server using the server ip address it went straight to it, but when I tracert to the server using the dns name it goes to the gateway and to other places before it starts to timeout I stopped the tracert after about 16 hops.

 

Do you have 2 different DHCP scopes for each range? Have you tried creating 1 scope to cover all 44 and 45 IP range?

[Theldron]

No we have 1 DHCP scope that covers both ranges.

[Michael]

Hey, thanks for the quick reply. On a 44 range machine it went straight to the server when I tracert to the server DNS name and IP address. On the 45 range machine I tracert to the server using the server ip address it went straight to it, but when I tracert to the server using the dns name it goes to the gateway and to other places before it starts to timeout I stopped the tracert after about 16 hops.

 

That would explain why logons are slow. Workstations are looking outside for information which is in fact on your LAN. I can't quite work out why .44 works and .45 doesn't however. Do you have more than one DC in your domain?

 

When you run an ipconfig /all with a .45 workstation, how does this compare to a .44 workstation? I suspect there may be a difference.

[Gardinho]

I would get your ISP to investigate. It sounds like a routing issue to me.

 

If your 45 range goes through the gateway then all of your clients on the 45 range are accessing your servers through the tcp port, which I guess is capped at 32MB.

Edited November 16, 2012 by Gardinho

[pantscat]

Sounds like a DNS issue to me rather than a routing issue.

 

If the trace route using the server's IP address is fine from a .45.x client but the trace route using the server's name isn't ok - then I'd suspect that the name isn't resolving to the correct ip address.

 

If you try and ping the server by name - what IP address does it resolve to?

[Gardinho]

If the client is going out to the internet first through the default gateway then it won't be able to resolve the DNS name on the way back in.

[Theldron]

Hi Pantscat,

If i ping the server name from a .45.x machine it tries to ping a 192.x number and times out, I am looking through DNS now to try to find where that number came from.

[Theldron]

Looking through DNS I have noticed that the server has 2 ip addresses registered to it in the Name Servers tab. 192.x.x and x.x.44.1.

[ChrisMiles]

can you ping both 44 and 45 addresses from your dns server? Is the dns settings in dhcp correct?

[pantscat]

@sadams1980 - there's your problem - because the DNS server has got two NICs both IP addresses will resolve the server name.

 

Is the server supposed to have two NICs?

 

In the DNS config you can choose which IP addresses the server will listen on.

[Theldron]

If i right click the the server name in DNS and go to interfaces I have 2 IP addresses selected the x.x.44.1 and 192.x.x.x. I have deselected the 192.x interface and I am going to try a machine. I will let you know how i get on.

Thanks again for everybodies help.

Cheers

[pantscat]

Cool.

 

You might find you get quicker results by looking at the DNS records and deleting any records pointing to the 192.x.x.x address...

[Theldron]

Thats worked, I really appreciate your help. Thanks alot.

[pantscat]

No worries!