mtu prob caused by new bb suplier

RouterOS General
1

Hi,

As part of bb upgrade I am having to use a different bb suplier for a month. This bb suplier seems to require a mtu of 1454, unfortinatley all the comps conected to my network have a mtu of 1458 and this results in them not been able to send email (etc) >1K.

My setup is this. MT with one nic and the network comps look at it as a gatway and then mt looks at a gateway (router+modem in one box) that conects to the phone line.

It seems prity certain that I am stuck with the 1454 mtu on the gateway, also access via it is been lent to me, so I would prefer not to hassel the owner about changing its mtu.

I’ve looked at mt but cannot really see if there is a way to overcome this at mt. Is there a way to do this with mt or will I just have to re-mtu all the comps?

Ta

2

How do your clients connect to the Mikrotik?

DHCP/PPPoE/PPTP?

if its a PPP connection just change the MTU/MRU in the profile for the PPP connection.. Make sure that it is 8 bytes less than your providers MTU (PPPoE uses at least 8bytes of overhead… in your case it should be 1444)

If it’s just plain old DHCP you’ll most likely have to change all the MTU sizes to something smaller than 1454

3

Well I am not to sure but think it is DHCP except that I have used static IPs & there is nothing under the PPPoE Server List & PPTP Server is not enabled. This is in the Interface List.

Pain

Ta though