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GRE Tunnel Source is Loopback Interface

pvrgallardo
Level 1
Level 1

Dear Concerns,

 

Good day.

 

I have this Topology and a link for my configurations. I want to know if on my given configuration the behavior of tracing the loopback interface between R1 and R4, the path is via non-GRE tunnel or its path should be via GRE tunnel, which is which?

 

https://hastebin.com/omigubajaw.diff

0.png

Looking forward for a positive response.

2 Replies 2

Hello,

 

what you would get if you would configure the route to the tunnel destination through the tunnel itself is what is called 'recursive routing'. The tunnel would flap constantly, and you would get ' %TUN-5-RECURDOWN:' syslog messages.

So make sure that from each end the tunnel destination is not routed through the tunnel itself.

 

Have a look at the document below for reference:

 

https://www.cisco.com/c/en/us/support/docs/ip/enhanced-interior-gateway-routing-protocol-eigrp/22327-gre-flap.html

 

 

Hello

basically you would advertise any network you which to be reached via the tunnel This can be done either statically or dynamically via an igp  

However making sure the source-destination or the tunnel isn’t advertised the same way due to the reason georg has has explained 


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Kind Regards
Paul
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