Set up jumbo frames

[avikivity]

We should set up Jumbo frames (MTU 9001) on our network interfaces.

I believe this would work with VPC peering just fine, since VPC peering goes through a logical router and so path MTU discovery will lower the path MTU if needed.

If not, we can set up extra interfaces with the larger MTU.

[avikivity]

/cc @syuu1228

[regevran]

reference