> I did a clean install, and I am starting from scratch on configuration
> for PPP. Seems to be OK, but the symptom is that ping and DNS work just
> fine across the interface, but every other protocol I've tried (ftp,
> ssh, http, ...) sends packets out but never get anything back (according
> to tcpdump -i ppp0). I have some indication that packets come back
> occasionally from the machines I'm targeting, but never very quickly and
> never the right ones.
Thomas J. Hamman, who had posted a similar question some time ago,
pointed me to the answer:
Our PPP server has explicitly disabled Van Jacobson TCP/IP compression,
but I had not specified the "novj" option in the /etc/ppp/peers/xxx file
(or in the options file or on the command line).
Once I disabled the compression, TCP/IP started working great. The
differential symptom which should have tipped me off (if I knew more
about this stuff :/ was that ping and DNS, which worked, use UDP and
hence are not affected by the VJ header compression scheme.
btw, I can't believe how easy IP masquerading was to set up! Half a
dozen lines cribbed from a Linux Journal article was all it took. Neat
stuff.
Thanks for the help!
- Tom
--
Thomas Lockhart
Caltech/JPL
Interferometry Systems and Technology
