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GRE Tunnel - Dynamic IP when tunnel destination

Manuel Nin


I have configured a GRE tunnel to communicate 2 different locations over internet.

I did it using static IP's using the command tunnel destination x.x.x.x and it worked it but I now these offices don't have static IP form the ISP, now are dynamic and the tunnel is down.

I wonder; Is there a way to add tunnel destination and the make the router check if the domain has a new IP each 5 minutes and update it automatically?



4 Replies 4

Philip D'Ath

What kind of devices are these?

Are both ends dynamic, or only one?

Hello,Yes, both ends are using dynamic IP.

Here is a good example from Cisco on how to do this.

Personally I prefer the older crypto map method, since it has native support for this, while VTI's require a script.

Joseph W. Doherty
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In theory, if your devices support scripting, it might do the job.  If you're interested in that approach, post a question in the EEM scripting forum.

Philip asked if both sides used dynamic IPs.  If not, a DMVPN setup supports spokes with dynamic IPs using NHRP.  (Don't know whether you can use NHRP directly for this.)

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