The interface of NIP2200 is always down

Publication Date:  2013-06-08 Views:  226 Downloads:  0
Issue Description
This customer used a pair of bypass interface which are interface A51  and B51 to protect the DMZ area. The topology is as follows:

When they finished the configuration, the traffic pass normally throw the bypass interfaces, but that remarked that the status of the interface G5/0/0 was down and there was no traffic size shown in this interface.

Besides, they set the policy as follows:

Alarm Information
Handling Process
1. From the picture above, we can see that the status of the interface is Administratively Down. We know that this indicates that the interface is disabled.

Then we ask the customer set us the diagnostic information, and the following information about the interface G5/0/0 can be seen which means this interface is shutdown by the customer.
interface GigabitEthernet5/0/0
link-group 5
port link-type access
port access vlan 1051
anti-ddos flow-statistic enable
anti-ddos server-flow-statistic enable

So we give the following solution:
           In the page “ System -> Configuration -> Interface”, click the corresponding interface GigabitEthernet5/0/0, and cancel the selecting “Silent interface”. The following picture is the example, need to cancel the “ ”.

2. After that, the customer replied that the interface was still down, and sent yet another diagnostic file. From this, the following information

bypass-link 5/0/0
switch bypass
bypass-link 5/0/2
switch bypass

  ===============display bypass===============
13:43:43  2013/05/20
Interface-1     Interface-2     BYPASS-Switch 
5/0/0           5/0/1           switch        
5/0/2           5/0/3           switch 

The default configuration is like this picture(for example):

But from the diagnostic file, the current configuration is as following:

This means the option “Status Swithover” is enable. The meaning of this parameter is shown in the following table:

Then we ask the customer to cancel select the option “Status Swithover”. After that, the interface G5/0/0 is up.
Root Cause
1. The interface is shutdown.
2. The configuration of the interface is mistaken.
3. The Expansion Interface Cards is broken.
When configuring the NIP 2200, for these two options “Automatic Recovery” and “Status Switchover”, the default configuration is recommended. That is, the option “Automatic Recovery” should be enable, and the option “Status Switchover” should not be enable.