can ping host IP but not dns

[Todd McDaniel_1]

Hey, I powercycled a box after a crash and now I can't ping the hostname, but I can still ping the IP. My dba's lsnr didnt come up on reboot so the db didnt start... They were able to start the lsnr with the IP address instead.

I know its a dns issue, but what should I be looking for? my resolv.conf didnt change. Is there some daemon I need to look at restarting?

[Ivan Krastev]

Check /etc/hosts for missing entries.


regards,
ivan

[Todd McDaniel_1]

I should also say that this is all from the host in question.

I can telnet to it using the hostname, but while I am logged in I can't ping it with the hostname, short or FQDN either.

Also, I cant ping several other boxes either, but i can ping one other box in the same group.

[Sandman!]

"/etc/hosts" as previously mentioned.

[Todd McDaniel_1]

I dont see anything wrong in the hosts file.

[A. Clay Stephenson · Accepted solution]

This is clearly a hostnames resolution problem but it may have nothing to do with the /etc/hosts file. Indeed, /etc/hosts may not even being looked at. You need to examine /etc/nsswitch.conf (if it exists) and then see what order is used for hostnames and what action is taken if a service is unavailable.

[Todd McDaniel_1]

Clay,

That was it. My /etc/nsswitch.conf file was missing for some reason. I didnt think to check if it was there.

When I restored it, my ping of its own hostname started working again.