Hello Everybody,
I need some assistance to help identify throughput issues for our DMVPN following the Cisco IWAN design.
Here are the details:
- Hub DMVPN - Cisco 4431 router with 1G Bandwidth
- Remote - Cisco 2921, 1921, 4331 routers - 2 WAN ports
The tunnels are used for backup and up and running. These same routers also have an additional WAN connected to our MPLS provider. The MPLS is the primary WAN link and the DMVPN is the backup for each respective router.
When running a speed test over the MPLS link we get our full bandwidth. However, when cutover to the backup DMVPN tunnel, the bandwidth is cut to about 20/10 for every device. I thought this was just performance issue for the 2900's but it is the same result for the 4331 which should be able to support DMVPN and many other features.
I am thinking the issue maybe on the HUB router. We have removed the encryption and just tried connecting using a GRE and we get the same results.
Is this maybe an issue of the MTU? I have tried both mtu path discovery and set the mtu to 1400 with adjust at 1360 but to no avail.
Again, whenever running over the MPLS we are good, but the minute we go over the tunnel we lose and users have issues uploading files across the GRE or DMVPN tunnel.
Any help would be greatly appreciated.
Thanks,
Brandon
