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Beginner

How to check status the NXOS's GRE Tunnel ?

Hello, everyone

I configured the GRE tunnel with 2 N9K.
However, there is no keepalive option in N9K.
How do I check the tunnel status between each other in N9K?
I've seen some use of ip sla between both tunnel ips.

In general, what method do you use?

Thanks.

1 ACCEPTED SOLUTION

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IOS routers have had the feature of GRE keep alive for quite a while. I was not aware that nxos does not have this feature, but am not surprised if it does not. Newer implementations such as nxos frequently do not have all of the features found in IOS. Some times those features are added in later versions of the new operating system. And sometimes Cisco decides that the feature is not so important and the feature is never added in the new protocol. I am not sure which will be the case for GRE keep alive in nxos.

HTH

Rick

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Hall of Fame Guru

If tunnel keep alive is not available then to check the status of the GRE tunnel I would ping the IP address of the remote end of the tunnel.

HTH

Rick
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I want to check the status automatically.
Should I check manually?

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Your original post asked "How do I check". I assumed that you would be the one checking. Sorry that I did not correctly understand what you wanted. For an automatic check you might use something like track, where you would track reachability of the remote end of the tunnel. One question about this approach is if you use track and it detects that the remote end is not reachable what would happen? Perhaps you might want to use an EEM script to detect changes in track status. Another approach might be to run a dynamic routing protocol over the GRE tunnel (something like EIGRP or OSPF) that builds a neighbor relationship and checks to be sure that the neighbor is reachable. If the neighbor goes down then you know that the tunnel is not working.

 

 

HTH

Rick
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I understood.
Originally, nxos does not automatically check the tunnel status?
In ios there is a keepalive setting.

Highlighted

IOS routers have had the feature of GRE keep alive for quite a while. I was not aware that nxos does not have this feature, but am not surprised if it does not. Newer implementations such as nxos frequently do not have all of the features found in IOS. Some times those features are added in later versions of the new operating system. And sometimes Cisco decides that the feature is not so important and the feature is never added in the new protocol. I am not sure which will be the case for GRE keep alive in nxos.

HTH

Rick

View solution in original post