Host Address Lookup for server <server> failed: The requested name is valid, but no data of the requested type was found

[ekisner]

We just finished switching our switches over, and we've implemented VLANs.

All servers (VMs and physical), switches, printers, and other "IT" items are on the default VLAN (1). In fact, no IP addresses changed on any of them... I did have to change the gateway address however. I changed the gateway address by editing the /etc/sysconfig/network file and then rebooting the host.

I am now experiencing a problem when I try to console into my VMs... I can use remote desktop connection to access them, and they're all running fine, however opening the console produces a little bar at the top that says:

Host Address Lookup for server failed: The requested name is valid, but no data of the requested type was found

My theory is that there is a lack of routing in place, but I'm far too afraid to play with that without knowing more from someone that knows more!

# route

Kernel IP routing table

Destination Gateway Genmask Flags Metric Ref Use Iface

192.168.10.0 * 255.255.255.0 U 0 0 0 vswif0

192.168.10.0 * 255.255.255.0 U 0 0 0 vswif1

169.254.0.0 * 255.255.0.0 U 0 0 0 vswif1

default 192.168.10.254 0.0.0.0 UG 0 0 0 vswif0

[java_cat33]

So before the networking change you could resolve the VM name via forward and reverse lookups without issue.......... now after the networking change....... DNS fails?

[ekisner]

Yes, DNS forward and reverse looks were just fine.. things were running smooth.

[Grevane]

Damn, dunno whether those &lt; &gt; in the title screwed up my post but I typed a nice long reply and the website had an error so all my text disappeared. So, apologies as this is the shorter "I hope my post doesn't get lost again" reply mate... sorry...

Anyway, the long and the short of it was to check the VLANs and failing that, get rid of them, go back to your old setup and reimpliment them bit by bit checking connectivity after each change no matter how minor you think it is.

Do all the vmhosts, guest servers and physical servers ping ok? You never mentioned the results of any basic connectivity tests. This would be also useful information to know...

Sounds like you are trying to access a server by name which resolves correctly but that resolved IP isn't accessible or something...

--&gt; Error value:

11004 The requested name is valid, but no data of the requested type was found.

That doc is in relation to troubleshooting AD errors but it backs up the DNS issues which again make me think the VLANs are not correct.

Depending on the VLAN complexity and how you implimented it, I would either go through the setup and make sure they are 110% correct, or just remove the VLANs entirely and if that fixes things, you know you did somethign wrong in the VLAN setup.

The probability of something completely unrelated happening at the same time as implimenting VLAN's which stops access to something on the network which funnily enough is exactly what VLAN's do is... well, probably very unlikely...

[ekisner]

Damn, dunno whether those &lt; &gt; in the title screwed up my post but I typed a nice long reply and the website had an error so all my text disappeared. So, apologies as this is the shorter "I hope my post doesn't get lost again" reply mate... sorry...

No need to be even a little sorry.. any advice you give is helpful and it's not exactly like I'm paying for access to these forums (unless it's included in SnS and I just don't know it?).

Also, sorry for not posting basic connectivity results... sometimes I forget the gurus can't actually read my mind >.< -to sum all of that testing up, I have full connectivity across the board.

The DNS troubleshooting you sent me didn't directly help, but their mentioning of AD did make a few bells ring.. was having an intermittent problem with my Exchange users, and the autoconfiguration testing tool was pointing to having AD lookup problems.

We have this annoying little problem (which happened while we were implementing the VLANs) where our SAN just... crashes. HP can't figure it out. However, when it crashes, of course all of my VMs crash too. In this case, I think it pooched the NTDS folder. By repairing that, I was able to get everything working normally again -even the email!

Thanks for pointing me in the right direction!

Edit:

The SAN crashing has been happening for months (every couple weeks) -was not the result of the VLAN implementation, as my post initially suggested it might be.