You have to be able to ping the box , can you reach the router via ping ?
this is the syntax , you may have to play with it a little depnding on what kind of server you are using (SUN HP etc)
Make a file on /tftpdir name it whatever you want in this case named pw
chmod to 666
the file pw contains
conf t
enable secret cisco
end
snmpset -c rw string x.x.x.x .1.3.6.1.4.1.9.2.1.53.x.x.x.x octetstring pw
the rw string = the read write snmp comm string configured on the router
the first x.x.x.x it the ip of the router
the second x.x.x.x is the ip address of the nms server(your unix box)
