UNIX for Advanced & Expert Users

Were you able to talk to the server in the meantime? ARP would be required to do that, if ARP was down you'd lose communication instantly.

In the meantime means after I executed the arp -d HOSTNAME command and before the connection was lost ?

If yes , I was accessing the server for less than 3 minutes.

I typed arp -d hostname and pressed enter.......it showed [IP ADDR] hostname deleted and then I did not realise the output and copy pasted the command arp -d hostname again few times and it returned <hostname> <IP adrr> ----

at that time I lost connection to the server after that I could not login at all.

I don't think the downtime has anything to do with your arp command. arp -d is almost certainly harmless, and in the circumstances it isn't, I'd expect to see problems instantly, not 3 minutes later.

Thanks Corona688 for replying me continuously. I was afraid I messed up the system. From your reply I understand arp -d might not have caused the issue.

Do you think if system had instantly throwed me out, arp -d is the problem ?
And in that case what could we do to recover the system so that we can login again.

Getting back to my old question, will rebooting the machine solve the issue ?

If arp -d had caused the problem, a reboot may have fixed it. Whatever custom ARP entries you deleted must have been in config files somewhere, or you'd need to type them in every boot. We have a complete and total lack of information now. It could be frozen, thrashing, hard-drive crashing, firewalled out, asking to set the time&date, on fire, stolen, or just plain turned off. I can't offer any advice. Go and look at the machine if you can.

Thanks Coronna688,I think I will ask the network team to look at the machine once. From you replies, I can say I did not do anything wrong with the system. I do not have direct access to the lab where the server is located. Actually I was trying to fix somother issue and encountered this one. And thanks again for all your replies

I agree with Corona688 100%. Go see the central computer. Start by logging in on the console (if the computer is up!) and work you way out in the direction of your problem computer.
As Corona688 advises the sort of comms commands which cut you off act immediately (ifconfig , route, kill, ... etc.). There are many commands with delay (init, shutdown, powerfail .... etc.).