TCP narcolepsy -- VJ botch in Solaris PPP 4.0

TCP narcolepsy -- VJ botch in Solaris PPP 4.0

Post by Thomas Masle » Wed, 20 Feb 2002 19:29:24

Just in case anyone else trips over this...

Solaris PPP 4.0 (in Solaris 8 07/01, 10/01 etc and Solaris 9 EA) generates
bad PPP_VJC_UNCOMP packets -- it should overwrite the IP protocol field
with the VJ connection id but it doesn't, so the id is always 6.

The result is that some TCP traffic patterns (e.g. telnet sessions) slow
down exponentially (because of the retransmit backoff), to the point where
they are pretty unusable.

The workaround is to use the "novj" option to pppd.

Judging by the summary, I think this is Sun bug 4626407 (though it beats
me why it's filed under the "pppoe" subcategory).

The bug was *not* present in the version of ANU pppd that was on the
Solaris 8 04/01 Companion CD;  that version works fine.

Thomas Maslen