ASR 4331 router goes down after shutting LAN interface

[monalisamuduli02]

Hi everyone ,

i have faced an issue on ASR 4331 series router as when i am trying shut LAN interface by CLI ,router goes down and we are unable to login that router .

after physically rebooting the router, it's back to normal state .

can anyone suggest why this issue is happening? and suggest anyway to fix this issue .   

[Leo Laohoo]

Before booting the router, did someone plug a console cable in and checked the logs?

[monalisamuduli02]

Hi Leo,

thanks for the suggestion .

will share the LOGS after connecting the device to the console .

[liviu.gheorghe · Accepted solution]

Hello @monalisamuduli02 ,

is the LAN interface the only way to access the router? In this case it seems perfectly normal to loose connectivity when you shut down the LAN interface.

In this case you don't have to reboot the router - just connect to it via the console cable as @Leo Laohoo suggested and "no shutdown" the interface.

Hope this helps.

[MHM Cisco World]

router goes down and we are unable to login that router

the router is down in monitor dashboard not in real 
and also this explain you can not login to router 
the IP use for telnet and for monitoring is this VLAN IP 
when you reboot you UP the VLAN again 
what you need is change the source IP for monitoring and for login 
ip telnet source-interface <<- this force router to use specific interface 

MHM 

[Joseph W. Doherty · Accepted solution]

Are you sure router really went down or possibly you just lost in-band connectivity?

In addition to what @Leo Laohoo suggested, have active console access before you shut the interface.  See if router is still operational via the console, and if it is, see if no shutting the interface restores in-band access.

If it does, then what @liviu.gheorghe suggests, i.e. you've blocked the in-band access path, or, as @MHM Cisco World suggests, that interface IP is being used for exclusive management.

Personally, I suspect the issue might be what @liviu.gheorghe suggests is the most likely, but we would need more information to confirm.

Again the most important part of Leo's suggestion is having a working console connection, ideally before you shut that interface.  Especially if you've stumbled across some wild and nasty bug.  BTW, what's the IOS version, and feature licences you're using?

[monalisamuduli02]

Hi all,

greetings of the day!!! 

i am informing here that now issue has been resolved .

thanks to everyone for prompt response and suggestion on this issue .

Issue : there was an issue in cable (ISP to router).