Interface Utilization issues on Cisco GRE tunnels (IOS-XR)
By default when you create a GRE tunnel (tunnel-ip1) on ASR9K routers it gets assigned default Bandwidth value of 8Kbps
which usually causes utilization monitoring confusion as Tunnel can carry as much traffic as its hardware parent interface
where tunnel is anchored to. You would see utilization values as high a 10,000% percent with default Bandwidth settings.
To fix this issue correct bandwidth value has to be assigned to Tunnel interface.
Ideally it has to match Bandwidth value from the parent hardware interface.
Example:
interface tunnel-ip1
description BBL-0000: INTERNET-VPN-TO-JP
bandwidth 10000000
ipv4 address xx.xx.xx.xx/30
load-interval 30
tunnel mode gre ipv4
tunnel source yy.yy.yy.yy
keepalive 10
tunnel destination zz.zz.zz.zz
tunnel dfbit disable