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ipchains blocks POP3 access

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3 replies

by rouse 1 view

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My newly installed rh7.2 server running sendmail cannot be accessed from my outlook clients uless I flush the ipchain rules. Can anybody look at this etc\sysconfig\ipchains and suggest a fix?
:input ACCEPT
:forward ACCEPT
:output ACCEPT
-A input-s 0/0 -d 0/0 25 -p tcp -y -j ACCEPT
-A input -s 0/0 -d 0/0 22 -p tcp -y -j ACCEPT
-A input -s 0/0 67:68 -d 0/0 67:68 -p udp -i eth0 -j ACCEPT
-A input -s 0/0 67:68 -d 0/0 67:68 -p udp -i eth1 -j ACCEPT
-A input -s 0/0 -d 0/0 -i lo -j ACCEPT
-Ainput -p tcp -s 0/0 -d 0/0 0:1023 -y -j REJECT
-A input -p tcp -s 0/0 -d 0/0 2049 -y -j REJECT
-A input -p udp -s 0/0 -d 0/0 0:1023 -j REJECT
-A input -p udp -s 0/0 -d 0/0 2049 -j REJECT
-A input -p tcp -s 0/0 -d 0/0 6000:6009 -y -j REJECT
-A input -p tcp -s 0/0 -d 0/0 7100 -y -j REJECT

I'm pretty sure it's rules 6&8, but I've tried deleting just those to no avail. So I just flush the whole thing and then clients can Pop the mail fine.

3 replies

by randyarnold

port 25 is SMTP.
port 110 is pop3.
SMTP is used for sending mail.
pop3 is a seperate server.

add a rule
-A input -s 0/0 -d 0/0 110 -p tcp -y -j ACCEPT
Good Luck!
Randy

by rouse

Thanks Randy & sorry took so long to post back. This fixed it, and the points are yours! I would like to know where to find a "for dummies" on this technique, since I think this is a crucial first line of defense for running services on the internet. The Man & info pages are slightly oblique (I couldn't gleen the proper syntax for deleting a chain rule). Again, much obliged.

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