Hello, I use Redhat6.2. There are services running like telnet,ftp,httpd etc. I also have 3 more windows machines connected in a LAN. I use samba server to directly access the files from linux machine to windows machines. A router is used for internet connection. Recently i changed my ISP. And also the router was also changed to cisco router. After installing the router also everything was working fine. The only thing i have changed using netconf is the Nameserver IP. Suddenly SMB & NMB services were down. I found I/O error while the nfslockd got started. During this time only the samba server was down. All the other services and networking was working fine. TO rectify the nfslockd problem, I just changed the device from eth0 to eth1 and again back to eth0. I found the nfslockd did not give the error.But the IP lookup from other machines were down(When i ping the linux machine from windows machines i get request timed out). I thought that the problem with the ethernet card. I changed the card, installed the ethernet device on the linux, but with no success.I changed the ethernet cables, but with success. I am struck with the same problem for three days, but i couldn't find a solution. Can anybody of you help me pls....

Check out your /etc/hosts file. Make sure that the IPs match.