GRE support for 3650 and 3850 switches

[davidfarley]

Hi,

Can anyone tell me how many GRE tunnels the 3650 and 3850 switches support (I understand GRE is supported on the new denali IOS)?

Kind regards,

Dave

[Richard Burts]

I was not aware that GRE was supported on these switches. But if it is supported then I would assume that its implementation would be similar to other devices where the main limit on the number of GRE tunnels is the number of Interface Descriptor Blocks. Each interface, including tunnels, needs it own unique IDB and so this is the primary limit on the number of GRE tunnels. There might also be some limitations based on the amount of memory available or factors like that.

HTH

Rick

[trnielsen]

I can say from experience that although the 3850 now has GRE support, I am having a lot of problems with getting them to actually work properly. 

My problems are almost as if the 3850 is ignore the tcp max segment size command on my tunnels in a secondary VRF. 

My suggestion would be to wait and test thoroughly prior to committing to an architecture that i have had a lot of issues with. The current case I have open with Cisco has recommended to downgrade from Denali to catalyst code... so buyer beware. 

[rmfalconer]

Up to 10 tunnels are supported starting on 16.1. There are limitations on the features available so check the tunneling feature guide to make sure you can do what you need.