here is an output from debug
Router2801#ping 172.12.123.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.12.123.1, timeout is 2 seconds:
*Nov 22 23:03:57.083: IP: tableid=0, s=172.12.123.2 (local), d=172.12.123.1 (Serial0/3/0), routed via FIB
*Nov 22 23:03:57.083: IP...