What MTU between two routers?

[brex]

I have a peculiar network setup that causes me to require two routers.
My laptop connects to router B, which then connects to router/adsl-modem A.

{Internet} ===MTU:1460===> [A] ---MTU:????---> [B] ===> Laptop


I have set up router A with all the correct settings provided by my ISP, one specifically being the MTU of 1460.

I now need to know what I should set router B's MTU at. Should it be the same at 1460, or the full network speed of 1500.

Please help if you know the answer. Thanks!

 

[Glhs958]

I am going out on a limb here but I would think you would have to set it either auto so it would detect the of router a's mtu or set it manually at 1460. if you had it at 1500 then you packets would get fragmented.

 

[brex]

Thanks for your response Glhs!
Unfortunately my old router doesn't have an AUTO setting.
I shall try it on 1460, but would appreciate if anyone could confirm this is correct.

 

[Glhs958]

Your welcome brex, I believe this would keep you from fragmenting the ip packet. As I seen it if you send a packet the size 1500 through one node to a node that only supports 1460 would cause every packet to fragment. So going with both at 1460 would keep each node working in harmony.

 

[brex]

Okay thanks. I'll keep it set to 1460.
Appreciate your help.

 

[brex]

Excellent. I shall use 1460 from now on.
Thank you.