RT2(config-if)#username gemo password ruby
RT2(config)#
Serial2/0 Using hostname from interface PAP

Serial2/0 Using password from interface PAP

Serial2/0 PAP: O AUTH-REQ id 17 len 15

Serial2/0 PAP: Phase is FORWARDING, Attempting Forward

RT2(config)#
Serial2/0 PAP: I AUTH-REQ id 17 len 15

Serial2/0 PAP: Authenticating peer

Serial2/0 PAP: Phase is FORWARDING, Attempting Forward

%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial2/0, changed state to up

RT2(config)#do ping 172.16.10.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.10.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/5 ms

RT2(config)#