MTU will not change

BigAmp · Post by **BigAmp** » Thu Oct 16, 2003 9:37 am

HI all,

I can't belive I am having to ask this again but I just can't remeber and I can't find an answer in any of the sites info, I am getting my laptop set up and I can not get the MTU to change for me. it keeps showing up as 1420.

I am running Windows XP and this is running at school / Rez so I am behind a firewall.. so am I right in thinking that the firewall is what is keeping my MTU down?

mnosteele52 · Post by **mnosteele52** » Thu Oct 16, 2003 10:02 am

No it's not the firewall unless it's a router which could do it. Are you using ICS?

BigAmp · Post by **BigAmp** » Thu Oct 16, 2003 10:05 am

I can't remeber what ICS means, we needed to get are laptops to have a key installed so we would be let on the network if that is what you mean. in rez it would just be the firewall.

mnosteele52 · Post by **mnosteele52** » Thu Oct 16, 2003 10:30 am

ICS is Internet Connection Sharing.

BigAmp · Post by **BigAmp** » Thu Oct 16, 2003 10:38 am

I don't think so, we just had to get the key installed so they know only the poeple in the right programs can get on to the school network. I am just out of it, or is there not Globle MTU value some where in the reg? but just in case how would I till if I did have ICS?

Andrzej · Post by **Andrzej** » Thu Oct 16, 2003 3:12 pm

so long time did not seen - be welcome
school server (also router) can limited MTU=1420 your internet connection
in both services:
ICS = internet connection sharing
VPN = virtual private network
or access manager program
mentioned limitation can be changed ONLY in MTU settings
in server (or router - respectively)

BTW some limitations (means additional encapsulation)
are from sq reason = customer ID

on SG Analyzer result MTU=1420 for your laptop you can see in:
--laptop wXP default MTU (not present by default
means value MTU=1500 or xp PPPoE MTU=1480)
--laptop MTU value equal 1420 - strongly recomended
--laptop MTU value rage = more than limited - NOT recomended
with MTU registry settings above limitted value you can see same problems
eg unable reach same www; fragmentation lanMTU slow down your speed

OTOH shure laptop registry value MTU you can see on SG Analyzer
if mentioned registry setting will be less than limitted value
+ you can try for own confirmation of registry inscription

yours : ... had to get the key installed
so they know only the poeple in the right programs can get on to the school network ...
is it means that you install on your laptop access manager prg(s) ?
---so mentioned access manager can limited MTU=1420

BTW in my ISP access manager
is dedicated PPPoE client (FanceTeleKom origin) with MTU=1492
can be easy repleced by any another PPPoE clients (router's; osXP's; ect)
but in your case may be simlar to AOL

IMVHO you can check your laptop settings
1. using SG TCP/IP Optymiser - see current settings
2. try MTU=1420 from another popular client PPPoE (own router or laptop wXP)
2. in the same internet connection - laptop directly connection to modem (if aviable for you)
3. in different connection - laptop directly connection to modem

:2cool: but on corporate, school network accept admin settings it means MTU=1420