Hei Rene,
Cisco says something else:
If port 1 goes down, port 2 comes up and starts forwarding traffic to switch C. When port 1 comes back up, it goes into standby mode and does not forward traffic; port 2 continues forwarding traffic.
But I Strongly agree with you! because i have done it on ME3400 live with customer:
When it was nothing connected to Gig 0/2 on ME3400:
GigabitEthernet0/1 GigabitEthernet0/2 <strong>Active Up/Backup Down</strong>
When he connected the lan cabel to Gig 0/2:
GigabitEthernet0/1 GigabitEthernet0/2 <strong>Active Up/Backup Standby</strong>
when he took Gig 0/1 out:
GigabitEthernet0/1 GigabitEthernet0/2 <strong>Active Down/Backup Up</strong>
when he connected Gig 0/1 back, For 5 sec the main interface was in standby mode:
GigabitEthernet0/1 GigabitEthernet0/2 <strong>Active Standby/Backup Up</strong>
Gig 0/1 took control:
GigabitEthernet0/1 GigabitEthernet0/2 <strong>Active Up/Backup Standby</strong>
Regards,
Jie