Networked DSL problems for one comptuer.. error loading some images and some pages..

[ThePunkerGuy]

Ok, here's the deal. I am using an Alcatel Speed Touch Home (upgraded to Pro) ADSL modem running PPP to connect all my comptuers to my dsl line. The modem is hooked to my 8 port switch. I have all my computer using it just fine (most computers have xp on them, and one with windows 2000). I set them all to use 192.168.0.XXX IP addresses and subnet mask 255.255.255.0, and i set the modem as 192.168.0.99. I set all the computer to use Gateway: 192.168.0.99 and then i set my primary and alternate dns to what they are suppost to be for my isp. For some reason, the computer with 2000 has some little problems sometime. Like.. page not found (when i know it is, and it works on my other comps) and sometimes like images wont be displayed.. they will be xed out when they work fine on all other comptuer. If ya have any ideas let me know.. thanks..
- Mike

 

[Zedric]

Sounds like the good old MTU problem. Try lowering the MTU. Strange that the other computers work though.

(I take it the modem has a built-in router?)

 

[ThePunkerGuy]

what is mtu and how do i lower it?
- Mike

 

[Zedric]

MTU is Maximum Transmission Unit. You use a registry hack to lower it. It's somewhere in the forums, it's been up before. Try searching. Someone else might remember (come on guys!).

However I'm not sure if it's the router that needs to set the MTU or the client. Since You have a hardware router that could be tricky.

Aw well, I'm to tired to be a good source of information right now.

 

[GoNz0]

intresting link

 

[Mainframeguy]

Bumping this thread because Lord just spoke with our ISP and apparently lowered his to x'05C0' (at least I am assuming that is what he means when he says 1472!). This is a massive 8 bytes lowered from what I believe is tha XP default of 1480...

More to the point I have made that change and found it has not helped - hence the thread bump and an especial shout out to Zedric, who clearly seems to have a good understanding of the Maxmum Transmission Unit and why your ISP might figure the Telephone gear your line provider is using needs you to adjust it.... And hopfully why it made not a bit of difference for me and LordofLA thinks it works for him!

Oh yeah - and Lord may post here if he is awake - but I hope he does not irritate me with a tactless remark (Says the king of tactless rmearks )

 

[Mooz]

ok, i havent read the whole thread but ... i had a similar problem recently .... so ...

fragmented traffic is the primary issue, normally caused by the overhead that ISP puts on your IP traffic,

the max setting is 1500 the lowest is 68 and somewhere in the middle is a happy place for you !

i would personally google-fu DrTCP and use that to test various settings on the client in question....

you can test the settings before using drTCP by doing the following

ping x.x.x.x -f -l 1500

where x.x.x.x = ip address of website that give you issues
and 1500 is the size to try

if the ping states that it cannot complete due to fragmentation then lower the number by ten and try again

if however the ping is fine at 1500 do not touch the MTU value as it is fine and the issue is somewhere other than TCP IP.

finally if the ping fails until you hit say 1410 then enter 1400 into DrTCP (1410 - 10 for the ip header) ... then reboot and try the web page in question through the brower ....

i hope that this has helped.!

(if so click the star !!)

 

[Mooz]

ps forgot to mention that the -f flag makes ping not allow fragmented traffic, and the -l set the size in bytes.

Mooz

 

[Mainframeguy]

Re: Networked DSL problems for one comptuer.. error loading some images and some page

I have no idea if it will help yet - but the star gets a click anyway, because that is an excellent post (although I'll have to wait and see how I get on with DrTCP, that is hardly the point)..... I'll /edit or post back on my results sometime (probably soon, because this is damn frustrating and I have just done the dishes, only a packed lunch to make and unifornm to fold then it probably may make it towards the top of my priority list and I may still be awake! thanks again

[EDIT] Yeah - that DrTCP made the changes for me fine and is a lot more handy than regedit - so your rep was definitely deserved and thanks to your explanation I feel a lot more comfortable that I know what I am doing - unlike the original note from Lord that says "change your MTU to 1472" which left me with a heap of questions! So thanks again (even if the test meant logging onto my online banking again and seeing how much money I do not have! [/EDIT]

 

[LordOfLA]

it wasnt that cryptic a note...

 

[Mainframeguy]

true - I worked it out - it was just kinda minimalist! [EDIT] Anyway - you don't get rep for that, can't be giving rep to you or there could be acusations of some kinda nepotism - or soem weird post from TB! [/EDIT]