MTU Backbone

[sebastien3]

Hello,

On an ISP network, good practice is to switch the backbone to an MTU of 9000 on the access interfaces between the different equipment.

Should we pass the sub-interfaces (VLAN) or access interface that allow to form the IGP with BGP/EIGRP processes by configuring an MTU of 9000 ?

The recommendation would be that the MTU be deployed consistently across the backbone. Agree on that ?

I am going to reproduce a complete lab with 2 ASR 1000 routers and 4 Catalyst 4500 switches with interconnection 1G and 10G link .

Thanks

[MHM Cisco World]

follow

[marce1000]

@MHM Cisco World Sorry but I thought we would be past that by now (= follow ?)

 M.

[marce1000]

 - You may find this thread informative : https://community.cisco.com/t5/routing/disadvantages-of-increasing-mtu-router-buffers/td-p/3896463

 M.

[sebastien3]

@marce1000 Thanks, but that doesn't really answer my question...

I'm trying to figure out if I should do this :

SW1 Ten1/1---- Ten1/1 SW2 => MTU 9198

This connection between the switches is a trunk port.

Now I connect an ASR router on each switch and use VLAN 11 for BGP, do I also need to configure the switch and router interfaces to 9198 ? The ASR accepts an MTU of 9216.