I use Fedora 7 and my /etc/sysconfig/iptables is as follows


now my interface connected to internet is ppp0
interface between my phone and computer is ppp1 (using bluetooth and DUN)

i want the phone to access internet through ppp0 . The above firewall config worked for me in FC5 , but it refusing to work in Fedora7. Please help....

I also ran the following command before trying to connect

Oh yeah, the redhat firewall... note: sudo iptables -L usually gives easier to read information.

... what you have is (apparently) a default accept policy for everything (bad), but all inputs get sent to the redhat defined chain (puzzling, but allows for more elaborate firemalls with extra chains). The redhat chain goes on to accept pretty much everything.

The firewall is too complicated to check easily, and it is a wonder it stops anything at all.

Here's a script that has been known to work
http://www.linuxquestions.org/questi...36#post2224036

The IP Forwarding section can be replaced with the following to use masquerading rather than a direct approach used above.
http://www.linuxquestions.org/questi...52#post2790552

Execute the script, then run:
iptables-save > /etc/sysconfig/iptables

Remember to make the alterations to suit your system: eg.
WEBFACE=ppp0
LANFACE=ppp1

But, of course, why would you suspect the firewall?

Thanks Simon, the script worked really well. Though If you have the time, can anyone tell me what was wrong in the earlier setup i was trying !?

-A PREROUTING -i ppp1 -j MARK --set-mark 0x9
COMMIT
# Completed
# Generated by webmin
*nat
:OUTPUT ACCEPT [0:0]
:PREROUTING ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]
-A POSTROUTING -m mark -j MASQUERADE --mark 0x9

I believe that the problem was in applying the masquerade rule to the interface on the lan side of your firewall machine. You could try running the same rule set, with "ppp1" on the first line I copied changed to "ppp0", your internet interface, if you want to identify the problem. There may be other problems, but that looks like a necessary change to get your previous script to work.

Yep... it had to be something like that.
If the original script was just copied over there wouldn't have been a problem. But it looks like you were doing it from memory or notes rather than backup.

It is very easy to mix up the interface names like that. Another common mixup is to make a loop where two or more chains pass a packet back and forth forever.

Anyway, using (intelligently named) variables in the script is a kind of discipline which can avoid this sort of confusion.

Of course I could have just told you... I just chose to act in your best interests by solving the meta-problem first. You'll find that script very easy to understand and modify as your needs change. It also gives a more secure firewall... though you may need to explicitly open a port sometimes.


btw ${interface}, I think, needs to be $WEBFACE