3650 - lost link after 4 hours

[theis_t]

Hello,

My Name is Thomas.

I come from the PBX World.

I have no experience with cisco switches.

Here my question/Problem:

I have a problem with a link to a Cisco 3650 switch.
Since some days, i lose after 4 hours the link to a avaya PBX Gateway.
I have replace and reinstall the Gateway, but the issue still stands.

I discussed the problem with the IT Admin who installed the switch, but he says that the problem not the switch is...

Has anyone ever had such a problem?

Greetings
Thomas

[Leo Laohoo]

What is the exact IOS version is the switch running?

[theis_t]

Hi,

sorry, i don´t know that.

I hope the currend, the switch is 2 month old

[Julio E. Moisa]

Hi Thomas,

Could you please share the configuration of the port:

show run interface fax/y

also the output of following commands:

show ip int brief

show interface status

In order to see the IOS version, you can paste the output of: show version

Thank you 

[Predrag Jovic]

4 hours - that is matching how long switch will keep ARP entry until it need to be resolved again. Check arp table before and after switch looses connection to PBX.

You can try to reduce ARP to be a little smaller than MAC address table entry timeut ( < 5 minutes).

Also, you can try to add static ARP entry:

arp <IP address> <mac address> arpa

[theis_t]

Hello,

Thank you for all the infomations.

I will talk on Monday with the IT Guy to check the Points and give you the feedback.

Br

Thomas