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Date:      Fri, 11 Jan 2002 12:05:54 -0500 (EST)
From:      freebsd-questions@juicer.orange-carb.org (Colin Henein)
To:        freebsd-net@freebsd.org
Subject:   pppoe problem (not tcpmssfixup)
Message-ID:  <20020111170554.23144.qmail@mail.orange-carb.org>

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Greetings freebsd-net types.

I am having a serious problem with pppoe networking on my 4.4-release
system. I realise that this isn't a list devoted to answering user
questions, but I have tried freebsd-questions, and I think this issue
is a bit too technical for that forum.

I hope you understand that I've tried to solve this problem myself for
months, and I've thoroughly researched related problems (i.e. black
hole routers) on the net. I've tried to find relevant answers in the
archives of this list, and I've tried to contact others on the net to
no avail.

I should mention up front that I've been using FreeBSD for many years
now, and have a solid understanding of IP and related protocols,
including reasons for and mechanisms used in IP packet
fragmentation. If things get too hairy I can get my copy of Comer
out. So if you think you can help, don't hold back the technical
details on my account...

I hope you'll indulge this question, as you're really my last resort.

I am on ADSL service (magma.ca), and the FreeBSD box is connected
directly to my Nortel 1meg modem. I have an "inside" network as well,
which pretty much only sends and receives web traffic. I have no ports
that open through onto the inside network, so all incoming connection
requests terminate on the FreeBSD box itself.

I have the classic ADSL problem of not being able to get replies back
from certain websites (whether telnetting to port 80 from the FreeBSD
box, or using IE on my powerbook on the inside network). This I can
deal with through proxies.

The really critical problem, though, is that I also am running an SMTP
server (qmail) and have trouble receiving emails from certain sites.

If I remove the FreeBSD box from the loop and plug my powerbook
straight into the 1meg modem then I can hit all the websites that are
problemmatic with FreeBSD. This makes me suspect either my
configuration of FreeBSD (more likely) or the OS itself (less likely).

I understand the black hole router problem, but an upgrade to
release-4.4 with the default tcpmssfixup option on ppp doesn't solve
the problem. (My ppp.conf file is appended to the end of this
message.)

The www problem I can get around with proxies, but the SMTP problems
are more serious. I am dropping emails from a few hosts on the floor,
and a few specific mailing list subscribers are having serious
problems. What happens is that inbound SMTP connections hang after my
FreeBSD box sends the 'go ahead to send data' response. Here is a
captured dialog between my mail server (mail.orange-carb.org) and one
of the problematic senders (tomts9-srv.bellnexxia.net):
        > 220 mail.orange-carb.org ESMTP^M
        < EHLO tomts9-srv.bellnexxia.net^M
        > 250-mail.orange-carb.org^M
        > 250-PIPELINING^M
        > 250 8BITMIME^M
        < MAIL FROM:<normand.levert@sympatico.ca>^M
        > 250 ok^M
        < RCPT TO:<members@hotrak.ca>^M
        > 250 ok^M
        < DATA^M
        > 354 go ahead^M
        > 451 timeout (#4.4.2)^M
        > [EOF]
To me this sounds very similar to the black hole router problem, in
that the connection just sort of times out when bulk of the data is
coming.          

As those familiar with Canadian networks might expect, my attempts to
contact anyone technical at bellnexxia's NOC, or sympatico's IS people
have been met with resounding silence.

I desparately need a solution to this that I can implement
myself. Even my own ISP will be hard to convince since they explicitly
will not support anything that isn't Mac/Windows/Linux.

I'm hoping that someone in this forum will be able to shed some light
on this situation, offer some suggestions for how I can diagnose this
problem more completely, and perhaps even tell me how I can fix
things.

Thanks for considering this issue.
Colin


--------- ppp.conf -----------
        |magma:
        | set redial 30.120 0
        | set reconnect 120 9999999
        | set device PPPoE:ed1
        | set MRU 1492
        | set MTU 1492
        | set authname #########
        | set authkey #########
        | set log Phase
        | set dial
        | set login
        | set ifaddr 64.26.169.169 10.0.0.2/0 255.255.255.255
        | set timeout 0
        | set cd 5
        | enable lqr
        | set lqrperiod 10
        | set crtscts off
--------------------------------




--
             || when we're little kids maybe we need stories 
Colin Henein || to help us go to sleep. but sooner or later we 
             || need stories to help us wake up... -- Utah Phillips


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