Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
New Member

MTU and fragmentation issue

Hi all,

recently my company deploy Remote access VPN and MPLS...and I read lot about MTU and fragmentation issue... example GRE Tunnel, if fragmented the process level down from cef to proccess switching which is slow, is that right? how we know/detect that in our VPN, there is fragmentation and what forwarding instance the router used?

1 REPLY

Re: MTU and fragmentation issue

Hi there,

Fragmentation is seen in high CPU utilization.

"sh int" command on the interface with the crypto map apply will show you the number of fragments.

The thing is to specify the correct mtu "ip mtu" on the interface with crypto map, and in case your hosts will not know Path MTU discovery, to add "tcp mss adjust".

Please rate if this helped.

Regards,

Daniel

132
Views
0
Helpful
1
Replies
CreatePlease to create content