[H] lmhosts file?

[DHSinclair]

If I believe I need to bring another device (an old router) on to my LAN 
for continued troubleshooting, should I update my current client's lmhost 
file to disclose this "new" device B4 I plug the brick in?
The reason to put the device on my LAN is to try and see if the http 
interface works or not.
So far, only the old telnet (rs-232c) works to this device........ :(
Thanks,
Duncan