topic Re: Communication between 2 network segment in General Topics

Communication between 2 network segment

xiaolin01 — Thu, 23 Dec 2021 03:24:08 GMT

Hello,

I have a PA-220 firewall. There is a normal switch connected on ethernet 1/4. The switch is connected to the equipments of 2 network segments, 10.1.240. * and 192.168.5. * .

These equipments need to communication now. But I can't change their IP. Can I do this through the port settings of the firewall?

My idea is to add a new sub port to ethernet 1/4 and set it to 10.1.240.*. Then I will add a NAT to connect ethernet 1/4 and the sub port. Is it right?The pictures are the current settings of the firewall.

I have just started to learn the settings of network structure. There are too many concepts in it. 😥 Do you have any recommended learning materials?

Thanks

Re: Communication between 2 network segment

ShaiW — Thu, 23 Dec 2021 10:17:56 GMT

Hi @xiaolin01

So basically what you need is to add another network segment to the firewall, but that network segment is using ethernet1/4 that now has an untagged VLAN assigned.

You need to first see how the switch is configured for 10.1.240. * and 192.168.5. *. Does each subnet have a 802.1q VLAN-ID assigned to it?

Assuming both have VLAN-IDs you need to add a sub-interface on ethernet1/4 and configure 10.1.240.x/yy on it along with its VLAN-ID.

Next if 192.168.5.* has a VLAN-ID you will need to create another sub interface for it and move the configuration there because once you create a sub-interface - the 'parent' ethernet1/4 will be the untagged VLAN - and this all depends on the switch configuration.

Next configure a trunk port on the switch and move the connection between sw<->fw to trunk (trunk ports can carry multiple VLANs).

Lastly - verify rulebase allows this zone communication.

I will start without NAT at the moment to see if basic communication is working.

Shai

Re: Communication between 2 network segment

OtakarKlier — Thu, 23 Dec 2021 15:43:17 GMT

Hello,

You will not need a NAT. The above information is correct. I just posted a similar config (it does not use sub interfaces, but the concepts are the same).

https://live.paloaltonetworks.com/t5/general-topics/cannot-reach-server-at-dmz-via-nat/td-p/455022

Regards,

Re: Communication between 2 network segment

xiaolin01 — Fri, 24 Dec 2021 02:41:36 GMT

Thank you.@ShaiW

The switch is a unmanaged switch. So I think I need to make it in the firewall.

Neither of 10.1.240. * and 192.168.5. * have a VLAN-ID.

Do I need to make 2 sub interface?

e.g. ethernet1/4.1 and ethernet1/4.2, configure them and than make a trunk between e1/4.1 and e1/4.2. Or can I make a trunk between e1/4 and e1/4.1?

Re: Communication between 2 network segment

OtakarKlier — Fri, 24 Dec 2021 16:32:30 GMT

Hello,

If you want to use vlan id's then go with your first option, ethernet1/4.1 and ethernet1/4.2. Make them all layer2 interfaces and put the IP on the VLAN in the firewall. It give you more flexibility (my opinion).

Regards,

Re: Communication between 2 network segment

xiaolin01 — Sat, 25 Dec 2021 10:09:57 GMT

Thank you. I will try.

I set it up and changed e1/4 to layer2.

But my interface is different from yours. I don't know how to set it in static routing (picture 5).

12345

Re: Communication between 2 network segment

OtakarKlier — Sun, 26 Dec 2021 22:43:17 GMT

Hello,

For the Next-Hop, use the vlan instead of an IP Address.

Regards,

Re: Communication between 2 network segment

xiaolin01 — Wed, 29 Dec 2021 04:34:36 GMT

😅Sorry, I have made the same config as your post. But it doesn't work. When I set my IP to 10.1.240.*, I can not ping 10.1.240.1 and 192.168.5.* When I use 192.168.5.* the situation is the same.

InterfaceInterface -VlanZonesVlanRoutesPolicies

Re: Communication between 2 network segment

OtakarKlier — Thu, 30 Dec 2021 15:40:37 GMT

Hello,

The switch port you plugged PA port 1/4 into, is it setup as a trunk port? Also in order to ping a PAN interface, your management profile must allow for ping.

Regards,

Re: Communication between 2 network segment

xiaolin01 — Fri, 31 Dec 2021 02:15:22 GMT

Hello,

😥Sorry, I forgot to setup trunk port. The switch is old and unmanaged, it's a layer2 switch. I can't set it.

Can I make trunk port on firewall? I didn't find where to set it. Or should I buy a new layer3 switch?

Regards,

Re: Communication between 2 network segment

OtakarKlier — Fri, 31 Dec 2021 18:14:23 GMT

Hello,

I would setup two interfaces on the PAN with layer 3 vlan interfaces. Then setup vlans on the switch.

Cheers!

Re: Communication between 2 network segment

xiaolin01 — Sat, 01 Jan 2022 14:29:27 GMT

Hello,

Sorry, I don't understand you. There is no setting options on my switch. I don't understand where I can make setting about vlan or trunk on the switch.This is it's manual.

https://static.tp-link.com/manual/2021/202107/20210719/7106509291_TL-SG1016DE_IG.pdf

I have a another new switch that can log in and make setting. But I think the switch connecting the two networks does not have that.😥

Regards

Re: Communication between 2 network segment

OtakarKlier — Mon, 03 Jan 2022 16:46:23 GMT

Hello,

Doesnt look like the switch can be managed. You might be able to get away with plugging PAN interfaces 1/1 and 1/4 into the switch and then the devices into the same switch. Not the best solution but should work.

Regards,