Can see some sites, not others from Client PC.

[Guest]

Hi,
I am not that knowldegeable when it comes to PC's so please bear that
in mind when answering.
I have 2 PC's running 'proper' versions of Windows XP Home that I
have networked together. However I noticed that the client PC will onl;y get
cetrain pages up? I can get on Google no problem and many other sites, but
vcannot get on MSN or any of the Windows Update sites and many others?
I know it is working sometimes as I have a 2Mb NTL connection and I
watched the same client PC download a driver from Nvidia at about 300Kb/s, so
it seems as though it's certain sites?
I have tried to fix it before by switching firewalls off and
anti-virus, reformatted client PC/ re-ran the net set up wizard countless
times andI just had a look on the microsoft site that wants me to go and edit
some MTU settings, but thought I would check here in case there are some less
drastic methods (I'm sure I've tried that MTU thing, but it was from a drop
menu not the regedit way)

Any Ideas, it's upsetting me now. John

 

[Chuck]

Hi,
I am not that knowldegeable when it comes to PC's so please bear that
in mind when answering.
I have 2 PC's running 'proper' versions of Windows XP Home that I
have networked together. However I noticed that the client PC will onl;y get
cetrain pages up? I can get on Google no problem and many other sites, but
vcannot get on MSN or any of the Windows Update sites and many others?
I know it is working sometimes as I have a 2Mb NTL connection and I
watched the same client PC download a driver from Nvidia at about 300Kb/s, so
it seems as though it's certain sites?
I have tried to fix it before by switching firewalls off and
anti-virus, reformatted client PC/ re-ran the net set up wizard countless
times andI just had a look on the microsoft site that wants me to go and edit
some MTU settings, but thought I would check here in case there are some less
drastic methods (I'm sure I've tried that MTU thing, but it was from a drop
menu not the regedit way)

Any Ideas, it's upsetting me now. John

John,

From the inconsistent nature that you describe, and the fact that ICS (the
client?) is involved, this almost certainly is an MTU problem. How much did you
read about the problem? The MTU issue is dynamic, and may not be solvable in
one or two tries. Be persistent.
<http://nitecruzr.blogspot.com/2005/06/internet-connectivity-problems-caused.html>

 

[Guest]

Hi Chuck,
I did see the part about the MTU settings and did my best
to 'fix' it by at first following Microsoft's instructions, and then another
web page with more or less the same, however when it came to actually
"Editing" inside the registry, the instructions were either unclear or in the
other case, did not match with what I saw on screen. So not wanting my PC
broke I wrote the above message.
After posting I tried that Ping -f -i 1500 thing, and it DID say
Defragment, however when I went lower @1470 it said "No connection" or
something, so I wasn't sure I was on the right path.
Then I remembered d/loading a bit of software last week while looking into
this problem, but I was unsure how it worked or what to do with it
I think it's called DrTCP or something.
Anyway I couldn't see much on the webpage I got it from about how to run
it, but had gleaned that the problem may be caused by too high a MTU
(Whatever that is? I imagine its like packets of data) at the Client? PC (The
one without direct internet conn) and on this Dr TCP it had a box with MTU at
the side, so I thought "what the hell"
So I ran it 1st on My Host PC and typed a value of 1500 in the MTU box and
hit the button, hoping I hadn't screwed something up. Then on the Client woth
a setting of 1470,and after I reset both PC's (Just about remembered!)
Now all is fine, I have updated the PC at m/soft and downloaded MSN
messenger (Could not connect to these before)
Seems very strange how some sites would connect, but others not, but i'm
just glad it's working.... Thanks for the help, you pointed me in the right
direction


And Thanks to DrTCP whoever you are... Auntie Fred

 

[Chuck]

Hi Chuck,
I did see the part about the MTU settings and did my best
to 'fix' it by at first following Microsoft's instructions, and then another
web page with more or less the same, however when it came to actually
"Editing" inside the registry, the instructions were either unclear or in the
other case, did not match with what I saw on screen. So not wanting my PC
broke I wrote the above message.
After posting I tried that Ping -f -i 1500 thing, and it DID say
Defragment, however when I went lower @1470 it said "No connection" or
something, so I wasn't sure I was on the right path.
Then I remembered d/loading a bit of software last week while looking into
this problem, but I was unsure how it worked or what to do with it
I think it's called DrTCP or something.
Anyway I couldn't see much on the webpage I got it from about how to run
it, but had gleaned that the problem may be caused by too high a MTU
(Whatever that is? I imagine its like packets of data) at the Client? PC (The
one without direct internet conn) and on this Dr TCP it had a box with MTU at
the side, so I thought "what the hell"
So I ran it 1st on My Host PC and typed a value of 1500 in the MTU box and
hit the button, hoping I hadn't screwed something up. Then on the Client woth
a setting of 1470,and after I reset both PC's (Just about remembered!)
Now all is fine, I have updated the PC at m/soft and downloaded MSN
messenger (Could not connect to these before)
Seems very strange how some sites would connect, but others not, but i'm
just glad it's working.... Thanks for the help, you pointed me in the right
direction


And Thanks to DrTCP whoever you are... Auntie Fred

Auntie,

Well, the way it works is the smaller you set the MTU, the more chance that all
of your packets will go thru (less routers to reject sending a packet the
smaller it is), but the more packets you have to send to get the same amount of
data thru, which ultimately slows down your surfing. So it's a tuning issue.

The Microsoft article 319661 recommends 1490 for the ICS client, presumably for
the host using 1500 which is the normal for regular broadband. So I guess they
are thinking that ICS adds 10 bytes of overhead. If you see excessive slowdown,
you can bump it up to 1478 until you see excessive dropped packets again, but
you can't really predict when it will become critical. And of course just
because 1470 works today, that's no guarantee that it will forever or for all
websites you might ever access.

The problem affects some websites but not others when the problem is caused not
by the ICS overhead, but by a router between you and the problem websites. The
Microsoft article explains how to identify the problem (but it's real intense to
try to understand).
<http://support.microsoft.com/?id=314825>

Anyway, thanks for the feedback.