I am not an expert with networking, but I think this could help.
Here's what to check and clear:
1. Check for stale ARP entries
arp -a
Look for entries pointing to the old 192.168.1.x range or with (incomplete) status. Clear the whole cache:
sudo arp -d -a
2. Check the routing table for stale routes
netstat -rn
Look for any routes still pointing to the old 192.168.1.x gateway. Delete any strays:
sudo route delete <stale-destination>
3. Confirm /etc/resolv.conf is clean
cat /etc/resolv.conf
It should show your router's IP as nameserver. If it still shows 192.168.1.1 or anything from the temporary DHCP range, that's your DNS problem directly. Fix it by restarting DHCP on the interface:
sudo service dhclient restart
Or force a DHCP renew manually:
sudo dhclient -r em0 && sudo dhclient em0
(Replace em0 with his actual interface name from ifconfig.)
4. Check for lingering NFS state
Even with the fstab entries commented out, the kernel may still have stale NFS state. Check:
sudo showmount -a
nfsstat -c
If anything shows up, a full reboot after the ARP/route cleanup above usually clears it. If not:
sudo umount -f -l /path/to/nfs/mount # force-lazy unmount any still-mounted NFS
