How to recover from this NIS & NFS client error?

I have a centralized NIS and NFS server on my server. I use this server to control 100 Linux clients, /$home/ directory and authentication are served by the centralized server. The other day in one of my clients unfortunately I disconnected the Ethernet connection (from the top panel), and the whole set-up was collapsed. Now I cannot login to that machine. It shows sort of yp bind error. I'm using ubuntu 12.04 LTS.