Operation Manual

The
dns
entryis vital. It tellsLinux to use an external name server.
Normally, these entriesare automaticallymanaged by YaST, but
it would be prudentto check.
If all the relevantentrieson the host are correct, let your system
administratorcheck the DNS server configurationfor the correct
zone information. For detailed information about DNS, refer to
Chapter25, The Domain Name System(↑Reference).If you have
made sure that the DNS configurationof your host and the DNS
server are correct, proceed with checking the configurationof
your network and network device.
4c If your systemcannot establisha connectionto a networkserverand
you have excluded name serviceproblems from the list of possible
culprits, check the configurationof your networkcard.
Use the command
ifconfig
network_device
(executed as
root
)to
checkwhetherthis device was properly configured. Make sure that
both
inet address
and
Mask
are configured correctly. An errorin the
IP address or a missing bit in your networkmask would renderyour
networkconfigurationunusable. If necessary,perform this check on
the server as well.
4d If the nameserviceand networkhardware are properlyconfigured
and running,but some external network connectionsstill get long
time- outs or fail entirely, use
traceroute
fully_qualified_domain_name
(executed as
root
) to trackthe network
route these requestsare taking. This commandlists any gateway
(hop) that a requestfrom your machine passeson its way to its
destination.It lists the response time of each hop and whether this
hop is reachableat all. Use a combinationof traceroute and ping to
track down the culprit and let the administratorsknow.
Once you have identifiedthe cause of your network trouble, you can resolve it
yourself(if the problem is located on your machine) or let the systemadministrators
of your networkknow about your findings so they can reconfigure the servicesor
repair the necessary systems.
NetworkManager Problems
If you have a problem with networkconnectivity, narrow it down as described in
Procedure A.6, “How to Identify NetworkProblems” (page 100). If NetworkManager
seemsto be the culprit,proceed as follows to get logs providing hints on why Net-
workManager fails:
1
Opena shelland log in as
root
.
2 Restartthe NetworkManager:
rcnetwork restart -o nm
Helpand Troubleshooting 103