I have a 2621XM runnin 12.4(7) Advanced Security.
The Serial 0/0 interface is configured with defaults as a Full T1
My Ethernet Interface that connects to the DSL modem has Firewall policy in place, NAT outside, ip virtual reassembly, ip provided by ISP, and that's about it. Very basic config.
What happens is that when I manually shut down the Ethernet interface, I loose my connectivity to this remote and the host store Serial interface goes into an up down state. And I cannot get into remote router without issuing no shut on the Ethernet interface.
Why would shutting down Ethernet Interface take down my Serial interface????
Clocking is set to internal at the host FYI.