Solved: mGRE tunnel issue

Shawnw4401 · ‎05-20-2017

Hello,

Problem:
I have a 6500 series switch that I am trying to set up multiple tunnels on. I have followed the instructions of the diagram below, but my tunnel on the 6500 series switch will not communicate with the other tunnels. The only change I've made from the below diagram is IP addresses and I am not using EIGRP but OSPF.

The end switches are 3560/3750 models. Can someone let me know if I am doing something wrong or is this not possible with these type of switches.

Reza Sharifi · ‎05-20-2017

Hi,

The 3750 and 3560 series switches don't support GRE.

From 3750 documentation:

The General Routing Encapsulation (GRE) tunnel is not supported by the Cisco Catalyst 3750 Series Switches. Even though this feature can be configured with CLI, the packets can be neither switched by hardware, nor by software, which increases the CPU utilization.

Link for more info:

http://www.cisco.com/c/en/us/support/docs/switches/catalyst-3750-series-switches/68461-high-cpu-utilization-cat3750.html

HTH

View solution in original post

Reza Sharifi · ‎05-20-2017

Hi,

The 3750 and 3560 series switches don't support GRE.

From 3750 documentation:

The General Routing Encapsulation (GRE) tunnel is not supported by the Cisco Catalyst 3750 Series Switches. Even though this feature can be configured with CLI, the packets can be neither switched by hardware, nor by software, which increases the CPU utilization.

Link for more info:

http://www.cisco.com/c/en/us/support/docs/switches/catalyst-3750-series-switches/68461-high-cpu-utilization-cat3750.html

HTH