ADSL/pppoe MTU pb with HTTP requests from intranet

[Gilles Lamiral <gilles.lamiral@free.fr>]

Hello,

I have a problem when a host from an intranet requests some
web pages through a gateway/firewall running openbsd.

Here are some elements:

- openbsd 2.8 (I can't upgrade easily)
- pppoe 
- nat

- I've already had a pb sending email from the openbsd gateway 
  so I set the mtu to 1412 and the sending mail pb disappeared 
  (good point).

- Intranet hosts running windows or freebsd both have the HTTP pb.
- Some web pages are well gotten, some are not.
- There is no problem with an RNIS connection.
- The openbsd gateway has not the HTTP pb.
- I've read the section "PPP & PPPoE" at
  http://real.ath.cx/BSDinstall.html
  but "enable mssfixup" happened in openbsd 2.9
- So I set the MTU to 1412 on the freebsd host and
  the HTTP pb disappeared (good point).
- So I set the MTU to 1412 on the windows 98 host but
  the HTTP pb remains (bad point).
    http://www.freebsd.org/doc/en_US.ISO8859-1/books/faq/ppp.html
    #MACOS-WIN98-PPPOE-FREEZE
    http://support.microsoft.com/default.aspx?scid=kb;EN-US;q158474

- I read how to upgrade an entire openbsd system but it seems a
  not very safe party. I can reboot but I need a good startup
  to login from a remote host (using IP, ppp not needed)

- As a last resort, I set up a squid transparent proxy.
  It works but I'd prefer to correct this TCP problem because
  I won't have a proxy for every UDP/TCP protocol.

So here are my questions:

- Can I get *just* src/usr.sbin/ppp/ from the 2.9 branch
  then compile, install and test.
- If not : Do I need a new kernel ?
           What do I need ?

Sorry for my bad english.
Thanks in advance.

-- 
Au revoir,
Gilles Lamiral. France, L'Hermitage (35590).
33 (0) 2 99 78 62 49
33 (0) 6 20 79 76 06