TCP (FTP) problem - some sites - while emerging

I am in the process of trying out Gentoo/FreeBSD - I love
the idea of
being able to use the very cool portage system on BSD!

Anyway, I have tried the install twice, the second time
doing the
"emerge -e system" before the kernel build, but I
am getting stuck at
the same issue: I get TCP timeouts to some sites.  This is
such a
bummer, and I am asking if anyone knows a solutuon.  I have
seen some
other postings to this list that may be the same issue
(packet mangling?).

Anyway, as an example, I can never FTP to www.astron.com
(where the
"file" package, among other things, lives).  Even
if I use wget or lynx
to do an FTP connection, it simply hangs.  I *can* get to
this site
using Windows, Linux, and regular FreeBSD (non-Gentoo) from
the same
machine and on the same network, so it has to be something
to do with
Gentoo/FreeBSD in particular.

If I can find a way past this problem, I have high hopes of
setting up a
working desktop, and I'd be glad to contribute in whatever
way I can to
the effort.  Is the project active right now?  I have not
seen much
activity as of late.  I do wish the best for this project,
since I think
it is valuable!

	Thanks!  Joe
-- 
gentoo-bsdgentoo.org mailing list

Great!  That should be good to visit.  Is there a time of
day when
people are more likely to be on?  I may try this evening
(I'm in US
mountain time).

	-Thanks, Joe


Ignacio Arqué-Latour wrote:
> Joe
>> Is the project active right now?
> Yes
>> I have high hopes of setting up a working desktop,
and I'd be glad to
> contribute in whatever way I can to the effort.
> OK, that is the attitude!
> You are going to find plenty of help from the
developers in our irc channel
> (inclusive while you are installing),  please meet us
on:
> channel: #gentoo-bsd
> server: irc.freenode.net
> 
> I hope to see you soom in the channel 
> 
> -- Ignacio
> 
> On 4/18/07, Joe Peterson <joeskyrush.com> wrote:
>> I am in the process of trying out Gentoo/FreeBSD -
I love the idea of
>> being able to use the very cool portage system on
BSD!
>>
>> Anyway, I have tried the install twice, the second
time doing the
>> "emerge -e system" before the kernel
build, but I am getting stuck at
>> the same issue: I get TCP timeouts to some sites. 
This is such a
>> bummer, and I am asking if anyone knows a solutuon.
 I have seen some
>> other postings to this list that may be the same
issue (packet mangling?).
>>
>> Anyway, as an example, I can never FTP to
www.astron.com (where the
>> "file" package, among other things,
lives).  Even if I use wget or lynx
>> to do an FTP connection, it simply hangs.  I *can*
get to this site
>> using Windows, Linux, and regular FreeBSD
(non-Gentoo) from the same
>> machine and on the same network, so it has to be
something to do with
>> Gentoo/FreeBSD in particular.
>>
>> If I can find a way past this problem, I have high
hopes of setting up a
>> working desktop, and I'd be glad to contribute in
whatever way I can to
>> the effort.  Is the project active right now?  I
have not seen much
>> activity as of late.  I do wish the best for this
project, since I think
>> it is valuable!
>>
>>         Thanks!  Joe
>> --
>> gentoo-bsdgentoo.org mailing list
>>
>>
> 
-- 
gentoo-bsdgentoo.org mailing list

There are a couple of threads about similar TCP issues, and
one did
mention windowing.  I did try turning off rfc1323 windowing
per
instructions I saw, but it did not help.  I also noted that
Nathan Smith
(post: http://scriptstest.gentoo.org/gentoo-bsd/msg_00121.xml
) also said
playing with and turning off windowing did not seem to
help.

Nathan went further and captured packets, noting that ones
from the
Gentoo/FreeBSD system had bad checksums (they were mangled
somehow).
Another common experience is that regular FreeBSD does not
have the
problem - it is somehow specific to Gentoo/FreeBSD.  A
reliable test
case I found is trying to FTP to ftp.astron.com - never
works.

		Thanks, Joe


Justin Wyer wrote:
> Hi Joe, if you check the list archives you will find a
thread about the same
> problem. It is essentially a TCP window scaling issue,
you can check the
> archive for details, I am unsure if a solution was
found.
-- 
gentoo-bsdgentoo.org mailing list

On 4/19/07, Camille Huot <camgentoo.org> wrote:
> 2007/4/19, Joe Peterson <joeskyrush.com>:
> > A reliable test
> > case I found is trying to FTP to ftp.astron.com -
never works.
> >
>
> I'm experiencing the exact same problem. tcpdump show
bad checksums like
> Nathan, ftp ftp.astron.com doesn't work.
>
> My nic is:
> em0: <Intel(R) PRO/1000 Network Connection Version -
6.2.9> port
> 0xcc00-0xcc3f mem 0xdfde0000-0xdfdfffff irq 18 at
device 2.0 on pci1
> em0: Ethernet address: 00:11:09:35:c3:81
>
> Using a vanilla FreeBSD 6.2 kernel on Gentoo/FreeBSD,
networking is working.
> On #gentoo-bsd we're trying to find the origin
> of the issue.
> --
> Camille Huot

Victory!

Here is how I compiled a Gentoo/FreeBSD kernel which does
not produce
broken tcp packets:

1. I emerged =sys-devel/gcc-3*.
2. Used gcc-config to set gcc-3 as the system compiler
3. Edited the freebsd-sources ebuild to remove the gcc41
patch.
4. Emerged freebsd-sources
5. Compiled the kernel and rebooted to find I could make
normal TCP
connections to anyone, anywhere.

So gcc-4.1 seems to be the culprit here.  I will check
FreeBSD's
archives to see if this has come up, but I wonder if they
have moved
to gcc4 yet anyway.  So, give what I posted above a try an
let me know
how it worked for you.

-- 
Nathan Smith
ndansmithgmail.com
-- 
gentoo-bsdgentoo.org mailing list

Nathan Smith ha scritto:
> On 4/19/07, Camille Huot <camgentoo.org> wrote:
>> 2007/4/19, Joe Peterson <joeskyrush.com>:
>> > A reliable test
>> > case I found is trying to FTP to
ftp.astron.com - never works.
>> >
>>
>> I'm experiencing the exact same problem. tcpdump
show bad checksums like
>> Nathan, ftp ftp.astron.com doesn't work.
>>
>> My nic is:
>> em0: <Intel(R) PRO/1000 Network Connection
Version - 6.2.9> port
>> 0xcc00-0xcc3f mem 0xdfde0000-0xdfdfffff irq 18 at
device 2.0 on pci1
>> em0: Ethernet address: 00:11:09:35:c3:81
>>
>> Using a vanilla FreeBSD 6.2 kernel on
Gentoo/FreeBSD, networking is
>> working.
>> On #gentoo-bsd we're trying to find the origin
>> of the issue.
>> -- 
>> Camille Huot
> 
> Victory!

Can you try to recompile the kernel with gcc 4 but with
-O0?
cd /usr/src/sys/i386/compile/GENERIC ; COPTFLAGS=-O0 make

Thanks

-- 
Timothy `Drizzt` Redaelli - http://dev.gentoo.org/
~drizzt/
FreeSBIE Developer, Gentoo Developer, GUFI Staff
There are two major products that come out of Berkeley: LSD
and UNIX.
We don't believe this to be a coincidence.      -- Jeremy S.
Anderson

On 4/20/07, Timothy Redaelli <drizztgentoo.org> wrote:
> Can you try to recompile the kernel with gcc 4 but with
-O0?
> cd /usr/src/sys/i386/compile/GENERIC ; COPTFLAGS=-O0
make

I can confirm that compiling with gcc-4 and COPTFLAGS=-O0
produces a
working kernel (i.e. no malformed tcp packets).  This was
after I
found that the gcc41 patch is also not causing the problem. 
After
getting a working kernel with gcc-4 I went back and used the
default
COPTFLAGS again and it broke again.  So I think this gives
us a fair
amount of certainty that the problem is caused by gcc-4
optimizations.

As to the reason why some FreeBSD users experience this and
other do
not, I am not sure.  The symptoms (broken TCP traffic to
some sites)
depend entirely upon the sites you are connecting to and how
your
connections are routed.  So it is possible that somebody
could have
this problem by not realize it.

However, using tcpdump I can tell that some machines
apparently do not
experience this problem, so it may be processor-specific
(which makes
sense given that it is an optimization problem).  I use a
Pentium M.
What are other people using that have been affected by the
problem?

-- 
Nathan Smith
ndansmithgmail.com
-- 
gentoo-bsdgentoo.org mailing list

Nathan, thanks so much for all the effort you've put into
this.  I am
quite relieved we now know more about it and that it's no
longer a
complete mystery.

As a data point, I have the issue (my "test site"
that is unreachable is
ftp.astron.com), and I am on a Fujitsu Lifebook P7120D,
which has this
processor:

* Intel Pentium M Processor Ultra Low Voltage 753 (1.20 GHz,
2 MB L2
cache, 400 MHz FSB)

	-Joe


Nathan Smith wrote:
> On 4/20/07, Timothy Redaelli <drizztgentoo.org> wrote:
>> Can you try to recompile the kernel with gcc 4 but
with -O0?
>> cd /usr/src/sys/i386/compile/GENERIC ;
COPTFLAGS=-O0 make
> 
> I can confirm that compiling with gcc-4 and
COPTFLAGS=-O0 produces a
> working kernel (i.e. no malformed tcp packets).  This
was after I
> found that the gcc41 patch is also not causing the
problem.  After
> getting a working kernel with gcc-4 I went back and
used the default
> COPTFLAGS again and it broke again.  So I think this
gives us a fair
> amount of certainty that the problem is caused by gcc-4
optimizations.
> 
> As to the reason why some FreeBSD users experience this
and other do
> not, I am not sure.  The symptoms (broken TCP traffic
to some sites)
> depend entirely upon the sites you are connecting to
and how your
> connections are routed.  So it is possible that
somebody could have
> this problem by not realize it.
> 
> However, using tcpdump I can tell that some machines
apparently do not
> experience this problem, so it may be
processor-specific (which makes
> sense given that it is an optimization problem).  I use
a Pentium M.
> What are other people using that have been affected by
the problem?
> 
-- 
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