[ILUG] ncftp vs. firewall?

[Thomas Ribbrock]

Hi folks,

I'm looking for some info with regard to ncftp and firewall. What happened
was this: If for example I tried to connect to ftp.heanet.ie with ncftp, I
get an error message "no route to host" and my firewall log showed this:

Mar 28 22:40:21 magrat kernel: IP fw-out rej ppp0 TCP MY_DYNAMIC_IP:61003 193.1.219.117:0 L=44 S=0x00 I=2648 F=0x0000 T=63

If, however, use the ordinary "ftp ftp.heanet.ie", the connection works
fine. Also, if I set ncftp to "Passive FTP only", it seems to work.

Hence, I'm looking for someone to shed some light on this or maybe give me a
pointer to more information, e.g. what's port 0 anyway - /etc/services
doesn't list it? The rule that blocks those packets claims to block
SUN RPC packets:

    ipfwadm -O -a reject -o -P tcp -W $EXTERNES_INTERFACE \
            -S $IPADDR \
            -D $ANYWHERE 0 87 111 512 513 514 515 540

($EXTERNES_INTERFACE is "ppp0" - I've got most of the rules for my firewall
from a German Firewall "HOWTO" - very helpful. I wonder what Babelfish would
do to it... ;-) )

Any ideas?

Thanks in advance,

Thomas
-- 
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      Thomas Ribbrock    http://www.bigfoot.com/~kaytan    ICQ#: 15839919
   "You have to live on the edge of reality - to make your dreams come true!"