🚀 go-pugleaf

John/Randy, anyone else,

I tackled this one.  Bottom-line he could only load pages that were a
few hundred
bytes in size...or he could load pages from certain (e.g. Microsoft
sites).

Problem was he was negoitiating TCP MSS=1460, but in reality his link
could only pass 512 byte packets
reliably.  Once I saw that in the trace, I did some size ranging pings
on him:

This pretty much sums it up:

Let's test that theory with some pings where we vary the size:


C:\users\default>ping -l 512 24.219.14.14 -t

Pinging 24.219.14.14 with 512 bytes of data:

Reply from 24.219.14.14: bytes=512 time=125ms TTL=114
Reply from 24.219.14.14: bytes=512 time=125ms TTL=114
Reply from 24.219.14.14: bytes=512 time=125ms TTL=114
Reply from 24.219.14.14: bytes=512 time=125ms TTL=114
Reply from 24.219.14.14: bytes=512 time=109ms TTL=114
Reply from 24.219.14.14: bytes=512 time=125ms TTL=114
^C
C:\users\default>^C

512 byte pings seem fine.

Let's try 513 bytes:

C:\users\default>^Cping -l 513 24.219.14.14 -t

Pinging 24.219.14.14 with 513 bytes of data:

Reply from 24.219.14.14: bytes=513 time=187ms TTL=114
Reply from 24.219.14.14: bytes=513 time=187ms TTL=114
Request timed out.
Reply from 24.219.14.14: bytes=513 time=219ms TTL=114
Reply from 24.219.14.14: bytes=513 time=172ms TTL=114
Reply from 24.219.14.14: bytes=513 time=219ms TTL=114
Reply from 24.219.14.14: bytes=513 time=157ms TTL=114
Request timed out.
Reply from 24.219.14.14: bytes=513 time=172ms TTL=114
^C

Ahhhh! Drops start happening.

Now let's go up to 1400 bytes (what you end up needing to surf):

C:\users\default>^Cping -l 1400 24.219.14.14 -t

Pinging 24.219.14.14 with 1400 bytes of data:

Request timed out.
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Request timed out.
^C
C:\users\default>

bamo:  100% packet loss.

Conclusion: We've got a packet size problem...not sure if it's the
network or your PC yet.


Forced his MTU down to 512 bytes and he's surfing fine now.

This obviously isn't a solution, so my next question is what the heck is
going on here.
At first it sounded a lot like the known ICS issue where it introduces
it's own 576 byte MTU...but he says he doesn't have that installed.


Oh yeah, and David didn't make it very easy on me, guy has cable modem,
but no phone...man!

lb.
(PacketBoy)

David Ciesnik wrote:
> 
> Hello,
> 
> I am almost at wits end with my cable modem connection!  Tech support is
> throwing their hands up in the air and I have never seen a problem like
> this either, so I'm not sure how to proceed.
> 
> I'm running win98.  I have three things under network preferences..
> "Network for MS clients", Network adapter, and TCP/ip.  Everything is
> setup correctly.  My network configuration is setup automatically from the
> DHCP server.  So my computer is assigned all of the proper values.  I have
> an IP address.  I am able to telnet out.  I can even ping my computer from
> an outside network.
> 
> But it appears that outside servers (webservers, mailservers) can't see or
> read my IP address, EXCEPT for microsoft owned servers.  Is this some
> conspiracy from Redmond????  I launch my web browser, and I can only get
> to msn.com, microsoft.com, hotmail.com.. but nothing else.  The sites that
> do load, load slowly, but they at least load.  For any other sites, like
> yahoo.com, it says "site found" and the loading status bar grows, but
> eventually it just times out.
> 
> Also, when I try to check mail.. either from MS outlook express or
> netscape mail, I get the status "getting message 1 of 10", so it KNOWS how
> many messages are on the server, but it can't retrieve them.
> 
> My connection worked fine with win95.  This problem started when I
> "upgraded" to win98 on Friday.
> 
> Anybody have any idea what's going on??  Why do MS sites load?  I
> reinstalled win98 twice already.  I uninstalled and reinstalled my tcp/ip
> stack several times.  Anybody else experience anything like this??
> Solutions?  By the way, Optel is my cable modem provider.
> 
> THANKS,
>                 -Dave

-- 
-------------------------
Lawrence Baldwin
Protocol Scientist
678-624-0924
http://www.mynetwatchman.com/about.htm - I'm under attack, now what?