Slack 2.6 default firewall settings and VM webcams

fnibble · 12-18-2013, 02:26 PM

Does anybody know if there is a firewall set up by default in Slackware 12.0 kernel 2.6 ?
I have installed a program which serves through the router, and it will only work on port 80. I have tried port forwarding on the router (Superhub2, VM) and this works for port 80, but not port 3000..3001 which I would like to use. So either there is an undocumented firewall for unusual ports at VM or in the router, or there is a default firewall is this version of Slack. I have tried to get into iptables, but it appears not to work properly, ie does not recognise ACCEPT as a valid arg. I can't find a config for iptables or the firewall, so I am stuck. Newbie help appreciated after much effort.

TobiSGD · 12-18-2013, 02:56 PM

Slackware 12.0 is unsupprted, you should consider to use a newer version.
Slackware does not set up a firewall by default, so your problem is most likely not on the Slackware side.

fnibble · 12-18-2013, 05:53 PM

Thanks for the above. It is a bit strange that there is an iptables binary somewhere in my install. and iptables -l does a return. I will check again. Can Slackware tell the difference between local originated requests, and stuff coming through the router? My newbie assumption was that packets coming that route were somehow translated so they looked as if they came from the router address, ie a machine which essentially is a LAN address, and it is the router which converts the packets going out. That would mean that the block is in the router.

TobiSGD · 12-18-2013, 06:09 PM

Quote:

Originally Posted by fnibble

It is a bit strange that there is an iptables binary somewhere in my install. and iptables -l does a return.

Nope, not strange. Slackware has iptables installed by default, but it is not set up, so you don't have a firewall running by default.

The rest of your question: Sorry, I don't know.

TracyTiger · 12-18-2013, 11:14 PM

Quote:

Originally Posted by fnibble

Thanks for the above. It is a bit strange that there is an iptables binary somewhere in my install. and iptables -l does a return.

Do you mean iptables -L run by root? (Capital L)

When no rules are configured (the default) the output should look something like this.

Code:

bash-4.2# iptables -L

Chain INPUT (policy ACCEPT)
target     prot opt source               destination         

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination         

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination

Quote:

I will check again. Can Slackware tell the difference between local originated requests, and stuff coming through the router?

I did a quick search for the basic netfilter packet path diagram and found it on this page along with other information.

Perhaps someone can suggest a good tutorial on netfilter and the use of the iptables command.

EDIT: netfilter.org was not responding when I posted this but is up now. The diagram and simple explanation I was looking for is there.