How to setup FTP proxying using the built in proxy code.
========================================================
NOTE: Currently, the built-in FTP proxy is only available for use with NAT
(i.e. only if you're already using "map" rules with ipnat). It does
support null-NAT mappings, that is, using the proxy without changing
the addresses.
Lets assume your network diagram looks something like this:
[host A]
|a
---+-------------+----------
|b
[host B]
|c
---+-------------+----------
|d
[host C]
and IP Filter is running on host B. If you want to proxy FTP from A to C
then you would do:
map int-c ipaddr-a/32 -> ip-addr-c-net/32 proxy port ftp ftp/tcp
int-c = name of "interface c"
ipaddr-a = ip# of interface a
ipaddr-c-net = another ip# on the C-network (usually not the same as the
interface).
e.g., if host A was 10.1.1.1, host B had two network interfaces ed0 and vx0
which had IP#'s 10.1.1.2 and 203.45.67.89 respectively, and host C was
203.45.67.90, you would do:
map vx0 10.1.1.1/32 -> 203.45.67.91/32 proxy port ftp ftp/tcp
where:
ipaddr-a = 10.1.1.1
int-c = vx0
ipaddr-c-net = 203.45.67.91
The "map" rule for this proxy should precede any other NAT rules you are
using.
plain