Problems giga ethernet

[Fernando Ferri Wollner]

I have an adapter that has a problem. When I try to do a nslookup, for example, from this machine, it takes a lot a time to return the prompt.
All the recommended patches are installed.
Any ideas?

Thanks,

[A. Clay Stephenson]

We need to distinguish between hostname lookup problems and networking problems.

1) ping using ip address - if that works ok the network is probably okay

2) ping using hostname - if that is slow then you have problems with hostname resolution. The primary dns server may be down and you are using the secondary after a timeout period has elapsed.

[Sridhar Bhaskarla]

Hi,

Look at your /etc/resolv.conf file and see if the name server mentioned there is responding or not. Try pinging to it and check the response. There may be a problem with your name server.

-Sri

[Patrick Wallek]

Is the host you are looking for in the local hosts file or in DNS?

You may also need to check your /etc/nsswitch.conf file and see what order files and dns are searched in.

[Bill Hassell]

nslookup tells you what is trying to do. If you have no /etc/nsswitch.conf, then all IP lookups are going to the first DNS server in the /etc/resolv.conf file. However, to enforce a little bit of security, the IP address listed in /etc/resolv.conf is queried by IP to obtain the DNS server's hostname. If the server doesn't know it's own name, the lookup may terminate (depending on revision and patches). If there are additional DNS entries in /etc/resolv.conf, the IP lookup will continue. If no servers respond, then between 30 and 90 seconds will go by before nslookup fails to locate the hostname. (it is unfortunately a common situation for DNS servers to not know their own name--an oversight by the DNS administrator)

Now things change if there is a file called /etc/nsswitch.conf. The typical method is to specify DNS first, then files (/etc/hosts) next. So if the DNS servers are not responding, once each server timeout occurs (30 secs each), nslookup will proceed to lookup the address in /etc/hosts. This same delay will be seen with telnet and other network connections as the code verifies the incoming IP address is verified as being valid.

To see if a specific server is working, use nslookup this way:

nslookup some_host DNS_server1

and repeat for each server listed in /etc/resolv.conf. This method will bypass nsswitch.conf and query only the listed server. If you have unreliable DNS servers, don't specify DNS first in /etc/nsswitch.conf. Use files, then DNS and put the few important IP addresses in /etc/hosts. A DNS server is a critical production resource but should not be the first choice for production systems.

[Fernando Ferri Wollner]

Sorry I think you might understood wrong. The nslookup was an example, the problem is with my adapter.
Thanks

[Patrick Wallek]

So what exact problems are you having? Have you checked /var/adm/syslog/syslog.log for errors? Have you checked that the cards configuration and the switch port configuration match? Any errors anywhere?

We need more information from you to be able to adequately help you.