opening ports on firewall

richardlhughes

What actually determines if a port is open on the firewall?

I have been struggling on pfsense configuration.

I have been trying to open ports 443 and 80 on my firewall to be re-directed to the appropriate lan ip address.

I have tried using both NAT and HAPROXY however, I can only get port 443 to open and port 80 is not getting any traffic. I am at a loss to figure out why this is being blocked. I have looked over the following information:
https://docs.netgate.com/pfsense/en/latest/book/firewall/troubleshooting-firewall-rules.html#firewall-troubleshooting-states

I couldn't find anything that points to being a problem with my setup. I would appreciate some ideas what I could be doing wrong.

Here is the rules I have on the firewall:

pass ipv4 tcp any any self 80 any

I've tried changing the destination to the different configurations however, nothing will resolve on port 80 to open the port.

Thanks,
Richard

KOM

I don't believe that you can forward a port that pfSense WebGUI is listening on. So, if you want to forward both tcp80 and 443, then you need to reconfigure your WebGUI to use some other port, like 81 or 444.

richardlhughes

@KOM said in opening ports on firewall:

tening on. So, if you want to forward both tcp80 and 443, the

Yes, I have the webgui configured on a different non-standard port.

KOM

Post screens of your NAT rules and WAN rules, maybe something there is wrong.

You can do a packet capture on LAN filtered to your LAN server and see if NAT'd packets are leaving the pfSense LAN interface.

akuma1x

Don't forget, your ISP also has to pass ports 80 and 443 thru to you over their connection. Since you said you can already get 443, I'm guessing they probably aren't blocking 80.

Jeff

richardlhughes

@akuma1x said in opening ports on firewall:

also has to pass ports 80 and 443 thru

I called them and they told me they are not blocking any ports.

akuma1x

Ok then, I'm pretty sure this is how you set it up. I say pretty sure, because I've got some port forwards on my pfsense box, but not 443 or 80.

NAT/Port Forward
Interface: WAN
Protocol: TCP/UDP
Source Address: Any
Source Ports: Any
Destination Address: WAN Address
Destination Ports: 80 or 443 (pick one)
NAT IP: your internal server IP address
NAT Ports: 80 or 443 (pick one)
Description: name it something appropriate

Then, at the bottom of this NAT rule, in the Filter Rule Association, pick the option to Create New Rule. That will automatically make a firewall rule on your WAN interface to pass the traffic. In your WAN interface firewall rule list, make sure the 2 default block rules are at the top - block rfc1918 and block bogon networks. Make sure this new firewall rule you just auto-created is immediately under the block rules.

Make sure your server on the internal network can accept traffic, then test from outside the network to make sure you can hit the server box in question.

Jeff

johnpoz

@richardlhughes said in opening ports on firewall:

I called them and they told me they are not blocking any ports.

1st step in troubleshooting any port forward issues is actually validate the traffic gets to your wan... There is nothing pfsense can do if traffic never gets there.

So this should always be step one... its as easy as going to say can you see me .org and testing for port 80 while you sniff on your wan... Do you see it get there?

Doesn't matter what your ISP says.. they might not be blocking it, but maybe something else is - say a nat router in front of pfsense for example..

KOM

@johnpoz I've already asked for screens and told him to do a packet capture but that advice was ignored.

johnpoz

Your post stated lan, which sure is step 2... But he needs to actually validate the traffic gets there before anything.

Derelict

List of things to check here:

https://docs.netgate.com/pfsense/en/latest/nat/port-forward-troubleshooting.html

Raffi_

@johnpoz said in opening ports on firewall:

@richardlhughes said in opening ports on firewall:

I called them and they told me they are not blocking any ports.

1st step in troubleshooting any port forward issues is actually validate the traffic gets to your wan... There is nothing pfsense can do if traffic never gets there.

So this should always be step one... its as easy as going to say can you see me .org and testing for port 80 while you sniff on your wan... Do you see it get there?

Doesn't matter what your ISP says.. they might not be blocking it, but maybe something else is - say a nat router in front of pfsense for example..

Another way to figure out if the ISP is not blocking ports is to use GRC service port scan.
https://www.grc.com/x/ne.dll?rh1dkyd2
They basically suggest running the All service port scan on a device not behind a NAT and with software firewall disabled (unprotected). Any ports that come up as stealth are most likely being blocked by your ISP. After running the test if you scroll down the Service Ports Scan Application Guide, you'll see more details on that. Of course don't forget to reenable the firewall after the test.

Derelict

That does not guarantee that something upstream is not responding on your behalf.

The only way to be 100% sure the traffic is arriving on your WAN is to packet capture on your WAN. If it does not arrive there, pfSense cannot forward it.

KOM

@johnpoz I tend to do it the other way around because in my experience, the traffic almost always gets to WAN. The problem is usually with the NAT itself or some other PEBKAC thing.

richardlhughes

Wan Rules

NAT Rules

HAPROXY (I've tried http and tcp for port 80 and cannot get port 80 open)

richardlhughes

@Derelict I have checked this list a couple times now. Didn't see anything standing out.

akuma1x

Alright, your NAT rules look correct, might want to make the protocol both TCP/UDP, and not just TCP.

Your WAN rules are incorrect. Your FIRST set of 443 and 80 allow traffic to just your firewall, not another LAN machine. If you move these two new bottom rules to the very TOP of your firewall rule list, the traffic should move like you are expecting/hoping.

Firewall rules are evaluated top down, first to match wins. That's why nothing is hitting 10.0.0.5, 80 and 443 are bouncing around inside the firewall itself, due to the first 2 top rules.

Jeff

Derelict

I don't know what didn't see anything standing out means. Did you see the SYN arrive or not?

If you packet capture on WAN for port 32900 and test from the outside, you should see the SYN packet arrive.

If you see it, then move your capture to the inside interface for port 32400, you should see the SYN packet sent to 10.0.0.37.

If there is no response, look at the server (10.0.0.37) and see why.

Derelict

@akuma1x said in opening ports on firewall:

Alright, your NAT rules look correct, might want to make the protocol both TCP/UDP, and not just TCP.

Pet peeve of mine. You shouldn't just randomly forward traffic. You should know if you need TCP, UDP, or both and forward what is required.

If he pcaps filtering on just the port, it will show both.

richardlhughes

@Derelict I didn't do the packet capture on the WAN, the troubleshooting list.

How do I setup packet capturing on the WAN? is this something I can setup on my pfsense machine or what is the best method?