[c-nsp] Cisco IOS DHCP server && setting MTU size

[Jerry Kemp]

Hello Robert,

Thanks for your reply.  Would the "ip tcp adjust-mss" be applied to the 
internal/LAN interface, outside interface or the Dialer1 interface?

Jerry K


Robert Boyle wrote:
> At 05:15 PM 6/6/2006, Jerry Kemp wrote:
>> In RTFM'ing, I have been reading Cisco's "Configuring the Cisco IOS 
>> DHCP Server"
>>   pdf manual, file name hipdhcps.pdf .  It appears that in the DHCP 
>> server
>> configuration, you can set raw DHCP options, to include option 26, 
>> which should
>> set the MTU size when a system pulls a DHCP address.
>>
>> Is anyone doing this currently on the list?  Does this work well?  I 
>> would think
>> that anything would beat going around and manually changing registry 
>> settings on
>> a bunch of wintel boxes.
> 
> Just use:
> 
> interface fastethernet0
>  ip tcp adjust-mss 1200
> 
> or whatever MSS you want to force. This will force the Windows boxes to 
> use a smaller MTU without any changes to the registry. This will work 
> with all machines without relying on DHCP either. You will need 
> something pretty modern. 12.3 or better probably, but if you are already 
> running PPPoE client and a 1760, you are probably already on 12.3(x).
> 
> -Robert
> 
>