configuring loopback devices ?? (newbie)

["Boedi Marjono" <bhud inti co id>]

i already try this command :
root# ifconfig lo 127.0.0.1      ---> success
root# route add -host 127.0.0.1 lo      --------> SIOCADDRT : file exist

i am already enable the kernel loopback device support in the kernel
configuration and recompile it but still don't work !!
i don't know the meaning of above message and how to fix it ??