Firewall rules for 2 subnets (cant print)

AndyRH

@galt007 If you try to go to a site on the internet that resolves to one of the address ranges you are using you will be routed to your internal system, not where you wanted to go.
Then you will spend time trying to figure out why you are getting an error.

NogBadTheBad

@galt007 If you access some Microsoft services it may think the service is sat on your local LAN.

johnpoz

@andyrh said in Firewall rules for 2 subnets (cant print):

trying to figure out why you are getting an error.

No they won't - they will ask here, saying its pfsense fault for some reason.. And never actually mention that they are using the public space internally ;)

akuma1x

@galt007 Key differences between public and private IP addresses

The main difference between public and private IP addresses is how far they reach, and what they’re connected to. A public IP address identifies you to the wider internet so that all the information you’re searching for can find you. A private IP address is used within a private network to connect securely to other devices within that same network.

Private IP addresses let devices connected to the same network communicate with one another without connecting to the entire internet. By making it more difficult for an external host or user to establish a connection, private IPs help bolster security within a specific network, like in your home or office. This is why you can print documents via wireless connection to your printer at home, but your neighbor can’t send their files to your printer accidentally.

Local IP addresses are also how your router directs internet traffic internally — in other words, how your router returns search results to your computer rather than another device connected to your network (like your phone or your partner’s phone).

https://www.avast.com/c-ip-address-public-vs-private

You DON'T want to be using public IP address space on your internal private IP networks. Something will eventually break, you won't know why because "it was just working fine yesterday", but this is going to be the reason why.

galt007

@johnpoz well you're correct on one account. I am a networking newbie.

I''l change it.

bingo600

@galt007 said in Firewall rules for 2 subnets (cant print):

@johnpoz well you're correct on one account. I am a networking newbie.

I''l change it.

Just change the 20.x.x.x to 10.x.x.x , and we'll al be happy

As mentioned above you can use "All of 10.x.x.x" for private use.

/Bingo

akuma1x

@galt007 This is a good first read, for setting up private IP address spaces:

https://www.lifewire.com/what-is-a-private-ip-address-2625970

The Internet Assigned Numbers Authority (IANA) reserves the following IP address blocks for use as private IP addresses:

10.0.0.0 to 10.255.255.255
172.16.0.0 to 172.31.255.255
192.168.0.0 to 192.168.255.255

The first set of IP addresses allow for over 16 million addresses, the second for over 1 million, and over 65,000 for the last range.

galt007

@bingo600 Funny thing about that. The company I work for uses 10.xxx. My network used to be 10.xxx. So when I connected my work laptop to the local network (using Cisco VPN) my network printer would disappear.

akuma1x

@galt007 said in Firewall rules for 2 subnets (cant print):

@bingo600 Funny thing about that. The company I work for uses 10.xxx. My network used to be 10.xxx. So when I connected my work laptop to the local network (using Cisco VPN) my network printer would disappear.

That's actually pretty common, to have 2 DIFFERENT networks using the SAME address space, and you don't find out until you connect the two of them together. I have heard lots of that using the 192.x.x.x space, since that's default private space on lots of consumer ISP modems.

If that's still a problem, you can change your home network (much easier than trying to get a company or organization to budge and change their internal network) to something else in the 10.x.x.x network range. Pick something like 10.20.30.40, or something like that...

galt007

@akuma1x I think Ill just go to 192.xxx. Seems best for the long haul

Thanks Everyone! Much appreciated.

akuma1x

@galt007 Yeah, that would work. Just be careful and check what your ISP modem/router hands out as private space on it's LAN port(s) or wifi network.

To do this, if you already don't know the address space, plug in like a laptop, or connect to wifi if available, and see what 192.x.x.x space your computer gets from the ISP modem. You typically don't want to use the same space as that. Then, on the pfsense LAN side, pick a different range. Here's an example.

ISP modem LAN network = 192.168.0.0/24

That means anything you connect to ISP modem could get possible addresses 192.168.0.1 - thru 192.168.0.254

So, then set your pfsense LAN network range to be something else, like 192.168.10.x/24 or 192.168.20.x/24 or similar. Make sense?

galt007

@akuma1x Makes sense. Thanks @akuma1x

johnpoz

@galt007 Unless your company was using same network as you, or overlapping network using 10.a.b.X shouldn't be a problem.

Unless they are using a /8 or /16 mask odds seem pretty high that they would be using 10.30.50/24 or 10.30.55/24 ?

If they are using such masks?? My 2nd reason applies to them as well ;)

the 172.16-31 network is prob less likely to have conflict, its rare you see those.. But I do see 10/8 way more than you should, which should be zero ;) or 192.168/16 again you should never see anyone using up the whole freaking network space for 1 segment... Doing so is reason 2 on my list ;)

galt007

@johnpoz Cant recall exactly what the subnet was.

I'm going to change my 20.30.x.x to 192.168.x.x after I do a quick check on what the ISP assigns as a default.

Currently I have 4 subnets

20.30.50.x
20.30.55.x
20.30.60.x
20.30.65.x

johnpoz

@galt007 said in Firewall rules for 2 subnets (cant print):

on what the ISP assigns as a default.

Are you behind a nat? I get a public IP from my isp.. Do you have a isp device, can you not put it into bridge mode so you get a public IP on pfsense wan?

galt007

@johnpoz I do get an IP assigned by the ISP. 47.x.x.x. I dont use my ISP router at all.

AndyRH

@johnpoz My ISP router is in DMZ mode and I get a public IP, but the router still uses 192.168.1.0/24 so I cannot use that network on the inside... {insert bad word here} ATT

johnpoz

@andyrh said in Firewall rules for 2 subnets (cant print):

but the router still uses 192.168.1.0/24 so I cannot use that network on the inside.

Huh? Are you using it for wireless or something? You could for sure use 192.168.1 on the inside.. As long as you had no need to get to this isp device IP for some gui or something.

AndyRH

@johnpoz I do on occasion need to get to the ATT Router, but it does not work if I use 192.168.1.0/24 on the inside because pfSense tries to route that network to the ATT router.
I did not try too hard as I am not yet close to using up the other 192.168 networks... but I am working on it.