In a project two USG2220 (FW1 and FW2) are used as main equipment, intermediate through the heart connection for conversation synchronization. There are two people do operation on the equipment at the same time, L uses the console access FW1, Telnet FW2 from FW1, H uses the console access FW2.
When the fault appears, L is configuring FW2, but H wants to visit FW1 this time, get L's permission H pulls out L console line and put its console line connect with FW1. Then H found login interface incredibly is FW2’s interface, and the two sets of equipment’s console connection is FW2’s interface.
Has the following several treatment measures:
1 L console to FW1 again, gradually quit to exit equipment.
2 H console to FW2 again, and through the command display users and free user - interface X remove the VTY thread of FW2.
3 restart FW2, obviously this is not a good solution.
Before H accesses FW2, FW2 has been L in operation through the Telnet. And L didn’t do logged out operation before H unplug L’s console line. Then H console to the FW1 occupied L’s VTY thread Telnet FW2 from FW1, so caused this phenomenon.