iptables issue: libipt_DPORT.so not found

Question

I'm trying to set up a proxy server on an Ubuntu Box, but my linux-fu is pretty weak and I'm stymied with an iptables issue.

I'm trying to execute this command:

iptables -A INPUT -d xxx.xxx.xxx.xxx -p tcp -m –dport 443 -j ACCEPT

The error I get back is this:

iptables v1.4.4: Couldn't load match `-dport':/lib/xtables/libipt_-dport.so: cannot open shared object file: No such file or directory

Try `iptables -h' or 'iptables --help' for more information.

There is, in fact, no file with that name.

iptables was not installed on my machine, I did:

apt-get install iptables

to install it. Finally, here's my distro info:

DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=10.04
DISTRIB_CODENAME=lucid
DISTRIB_DESCRIPTION="Ubuntu 10.04 LTS"

Any idea what's going on? If this is an obvious question, please point me to the relevant documentation; I'm kinda lost on even where to look, and Googling pulls up nothing.

Thanks!

Kevin

Answer 1

You should enter the command as follows:

$ sudo iptables -A INPUT -d xxx.xxx.xxx.xxx -p tcp -m tcp --dport 443 -j ACCEPT

Pay attention to the protocol name after -m and double dash before dport. You can also remove -m tcp from the above command as it is useless in your command.