some error about nfs

hello,everyone
when I open nfs on my linux server, and set the bootargs in the uboot, there is some error like this:

IP-Config: Device `off' not found.
ip_tables: (C) 2000-2002 Netfilter core team
NET4: Unix domain sockets 1.0/SMP for Linux NET4.0.
NET4: Ethernet Bridge 008 for NET4.0
lec.c: Aug 20 2007 13:01:25 initialized
Looking up port of RPC 100003/2 on 192.168.2.172
RPC: sendmsg returned error 101
portmap: RPC call returned error 101
Root-NFS: Unable to get nfsd port number from server, using default
Looking up port of RPC 100005/1 on 192.168.2.172
RPC: sendmsg returned error 101
portmap: RPC call returned error 101
Root-NFS: Unable to get mountd port number from server, using default
RPC: sendmsg returned error 101
mount: RPC call returned error 101
Root-NFS: Server returned error -101 while mounting /home/lim/Ramdisk
 
what is wrong, and what should I do ?				
--------------
李 明

MSN:lim.live@msn.com

务实奋斗，不断挑战
2007-08-20