[clug] Wierd problem connecting to www.mozilla.org
andwww.microsoft.com
Andrew Smith
andrew at coolchilli.com
Wed Dec 15 21:36:13 GMT 2004
Is there a special reason the XP box has the Music box as it's gateway,
rather than the Dlink (40.1)? The ICMP redirects are coming from Music
because it's default route is in the same subnet/interface as
HomeTheatre sending it packets.
The differing behaviour with web sites are likely due to HTTP/1.0 (a
connection per HTTP request) Vs HTTP/1.1 (one persistant connection per
site). Each request from the client generates an icmp redirect, so the
first packet usually gets dumped, subsequent packets follow the new
learned route. A good thing on XP is (under Tools/Options/Advanced)
Enable HTTP/1.1 and HTTP/1.1 through proxy connections, plus disable
"Show friendly HTTP error messages" so you get some usefull feedback,
rather than that pathetic "DNS or server error" page.
Andrew
On Thu, 2004-12-16 at 08:23, Donovan J. Edye wrote:
> Kim & Dale,
>
> Here is some more info on how things are set up here:
>
>
> HomeTheatre (192.168.40.100, GW 192.168.40.3, Problem XP Box)
> |
> |
> Music (192.168.40.3, GW 192.168.40.1, Fedora Core 3)
>
> eth0 Link encap:Ethernet HWaddr 00:40:63:D8:57:29
> inet addr:192.168.40.3 Bcast:192.168.40.255 Mask:255.255.255.0
> inet6 addr: fe80::240:63ff:fed8:5729/64 Scope:Link
> UP BROADCAST RUNNING MULTICAST MTU:1492 Metric:1
> RX packets:3855485 errors:0 dropped:0 overruns:0 frame:0
> TX packets:2642654 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:1000
> RX bytes:3627641391 (3.3 GiB) TX bytes:562622272 (536.5 MiB)
> Interrupt:12
> |
> |
> Router (192.168.40.1, GW Internet D-Link DSL-504 version 7.1.0.30 Annex-A
> (Apr 9 2003) R2.21.002.06.b7au R2.21.002.06.b7au)
>
> So:
>
> - I have no VPN or PPTP in play here
> - There is no PPPoE as far as I can tell
>
> What do you suggest I try here?
>
> TIA
>
> --D
>
>
> -----Original Message-----
> From: Kim Holburn [mailto:kim.holburn at anu.edu.au]
> Sent: Wednesday, 15 December 2004 22:31
> To: donovan at edyeweb.com
> Cc: Linux List
> Subject: Re: [clug] Wierd problem connecting to www.mozilla.org
> andwww.microsoft.com
>
> Sorry, that was text from a colleague, I try not to use windows and it
> may be more appropriate to pptp. The full MS thingy (technical term)
> is here:
> http://support.microsoft.com/?kbid=826159
>
>
> On 2004 Dec 15, , at 7:29 PM, Kim Holburn wrote:
>
> > Ahh:
> >
> > If you have a Windows XP box using ppp or pptp VPN and it can
> > mysteriously not
> > see some web sites (mostly overseas) but mostly networking is fine then
> > the following should fix it. Currently I find that out-of-the-box XP
> > machines using our VPN server can see http://www.apple.com.au/ fine but
> > http://www.apple.com/ doesn't work. Save the following text-only to a
> > `.reg' file like `VPNTunnelMTU.reg'.
> >
> > ---------- Cut Here ----------
> > Windows Registry Editor Version 5.00
> >
> > [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NdisWan\Parameter
> > s]
> >
> > [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NdisWan\Parameter
> > s\Protocols]
> >
> > [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NdisWan\Parameter
> > s\Protocols\0]
> > "PPPProtocolType"=dword:00000021
> > "TunnelMTU"=dword:000003e8
> > "ProtocolType"=dword:00000800
> >
> > ---------- Cut Here ----------
> >
> > Double clicking the file (with administrative privileges) should offer
> > to install the registry settings. Bravely agree to this and then
> > reboot. Works for me and it's alot least brain numbing than following
> > the Microsoft instructions below. The WinXP default VPN MTU value is
> > 1400 and the 0x3e8=800 value I've used above seems to work.
> >
> > On 2004 Dec 15, , at 6:47 PM, Dale Shaw wrote:
> >
> >> Without having a really good look at the packet trace, I'd be inclined
> >> to think it probably has something to do with Path MTU Discovery/ICMP
> >> blocking/PPP over Ethernet.
> >>
> >> Do you access the Internet over a PPPoE session? Maybe you could give
> >> us an overview of your connection arrangements. Look at lowering the
> >> MTU on the 'hometheatre' box or using TCP Maximum Segment Size (MSS)
> >> clamping.
> >>
> >> There are also some weird ICMP redirect shenanigans going on. Is the
> >> default gateway on 'hometheatre' set correctly? I can't see what the
> >> redirections are, just that there are a few.
> >>
> >> Anyway, the 3-way TCP handshake with www.microsoft.com is working, it
> >> just barfs when it tries to HTTP GET the front page. My money's on
> >> PPPoE/MTU and something in the path between you and the server dumping
> >> ICMP "Fragment Needed but DF bit set" packets.
> >>
> >> cheers,
> >> Dale
> >>
> >>
> >> On Wed, 15 Dec 2004 08:45:44 +1100, Donovan J. Edye
> >> <donovan at edyeweb.com> wrote:
> >>> B,
> >>>
> >>> Here is a dump of the conversation with www.microsoft.com. A few SMB
> >>> packets
> >>> that should not have been included. However it appears that the
> >>> problems
> >>> start around frame 10. Any pointers appreciated:
> >>
> >> [...]
> >> --
> >> linux mailing list
> >> linux at lists.samba.org
> >> https://lists.samba.org/mailman/listinfo/linux
> >>
> > --
> > Kim Holburn
> > IT Manager, Canberra Research Laboratory
> > National Information and Communication Technology Australia
> > Ph: +61 2 61258620 M: +61 417820641
> > Email: kim.holburn at anu.edu.au - PGP Public Key on request
> > Cacert Root Cert: http://www.cacert.org/index.php?id=16 ->
> > http://www.cacert.org/cacert.crt
> > Aust. Spam Act: To stop receiving mail from me: reply and let me know.
> >
> > Use ISO 8601 dates [YYYY-MM-DD]
> > http://www.saqqara.demon.co.uk/datefmt.htm
> > Democracy imposed from without is the severest form of tyranny.
> > -- Lloyd Biggle, Jr. Analog, Apr 1961
> >
> > --
> > linux mailing list
> > linux at lists.samba.org
> > https://lists.samba.org/mailman/listinfo/linux
> >
> --
> Kim Holburn
> IT Manager, Canberra Research Laboratory
> National Information and Communication Technology Australia
> Ph: +61 2 61258620 M: +61 417820641
> Email: kim.holburn at anu.edu.au - PGP Public Key on request
> Cacert Root Cert: http://www.cacert.org/index.php?id=16 ->
> http://www.cacert.org/cacert.crt
> Aust. Spam Act: To stop receiving mail from me: reply and let me know.
>
> Use ISO 8601 dates [YYYY-MM-DD]
> http://www.saqqara.demon.co.uk/datefmt.htm
> Democracy imposed from without is the severest form of tyranny.
> -- Lloyd Biggle, Jr. Analog, Apr 1961
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