Transparent proxying?

Tuomo Pyhala (
Tue, 29 Apr 1997 23:31:16 +0300 (EET DST)

Wen we did some HW upgrades and switched from kernel 2.0.29 to 2.0.30, the
transparent proxying feature stopped working. Following rule

ipfwadm -I -a accept -P tcp -D 80 -r 81

is used to redirect all http requests to our proxy. However, the
connection from ppp-client gets refused, though it can directly telnet to
81 port of server, and no matter if i change 81 to another port, the
connection still gets refused. If i remove the rule, everything seems to
work fine, so what is the problem?

Is this a (kernel) bug, or is this my fault?

P.S: I've enabled both SYN-flood protections, could they conflict or