My ISP Gave me DYNAMIC IP how to set on WAN interface

My ISP gave me a DYNAMIC IP address only, how can i set this up on my WAN interface?

There are two types of Dynamic IP - DHCP and PPPoE. If they gave you a username and password, then it is PPPoE. Otherwise it is DHCP. Either way, in your router, you set the WAN interface to use the appropriate type.

Do i need to Disabled the DHCP of my router? and use DHCP on my WAN side?

On the WAN side, you want your router to be a DHCP Client (it asks for an IP from your ISP). On the LAN side, you want your router to be a DHCP Server (it gives out IPs to the clients that ask for them - your computers, phones, etc).

No what i mean router from im ISP disable DHCP , and my WAN at pfsense will set to DHCP is that possible ?

So you are trying to replace the ISP router with PFSense? Do you have a separate modem and router, or is it an all-in-one? (If you don’t know, just share the model number)

No my set up is ISP router with WIFI my ISP said that they will give me dynamic public ip so if that ip will change how will i set up that on my pfsense WAN interface.
if i setup dynamic interface on my WAN pfsense the ISP router DHCP server should be enable but on my Interfaces on pfsense i will see the DHCP IP that ISP router is giving.
i want to see is my public ip on my WAN interface is that possible?

They are giving the dynamic public IP for the ISP Router, probably via DHCP. In order to get the publi IP on your PFSense, the router needs to be changed to Bridge mode, which turn it into just a modem. This also means the wireless from it will stop working.

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Ok thanks i just only set the ISP router to bridge mode , and DHCP on WAN side pfsense?

If you want PFSense to be your main router, and have some other solution in mind for wireless (an AP connected to PFSense’s LAN) then yes.

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Thanks for the helpful tips @brwainer

Hi, @markii did you ever get your network to work as you wanted it? If you haven’t I think you may not be able to, because of your Internet service provider not letting you run their equipment in bridge mode. My Internet Service provider Cincinnati Bell won’t let me run their equipment in bridge mode. So my only choice is to either try and find a modem only device which works on Cincinnati Bell network (hard to do), purchase my own router (same limitation as to the previous statement), or set up a double Nat situation, that is if I want to run custom equipment on my network.

Hi, @Shadowbane yes it wont work because my ISP is wont let me to bridge their device. so i let it that way and looking for another solution.

I was afraid the answer from your Internet service provider would be they don’t support putting their device into bridge mode. You only have two choices, finding a device your ISP will support in bridge mode or running a double NAT system. I think your best option is to set up a double NAT system. I know this isn’t ideal, but if you want to use Pfsense you will have to grin and bear it. As to how to set up such a network, I have no idea. I do know it will involve setting up one or two subnets at least. You will also somehow need the ISP device to forward your internet traffic to Pfsense.

Markii is trying setting up two internal networks, one ware all his devices are connected to and one so he can get out on the internet. Maybe @brwainer or @LTS_Tom or his staff could help us getting @markii IPS provided router to forward its internet traffic to Pfsense. It would help markii if we knew which ISP-provided router we are dealing with. So markii if you could list the make and what the IPS provided router is called we could look up the manual for that device and be more helpful to you.


Why don’t you just purchase your own internet modem for Cincinnati Bell and then put it into bridge mode? That way you prevent paying the monthly rental fees on the device. I did this with comcast. Device wasnt that expensive – I think like $60.

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As I mentioned in one of my previous posts, I can’t just purchase a modem and have it magically work with the Cincinnati bell’s network. There are several reasons why purchasing a modem then running in bridge mode won’t work in my case, two of the major stumbling blocks are lack of consumer manufactured fiber optic modems (by modems (I take you to mean just a modem, not a device that also routs and has builtin WIFI), and any three in one device that would work in bridge mode won’t work on Cincinnati Bells network.

As I stated in the above paragraph purchasing a modem or a three and one device is a huge task which I have yet found an answer. Cincinnati Bell is a Fiber Optic network. I have never found a consumer Fiber Optic modem. @kevdog I think the reason you had better luck than I did was that your internet service provider is also cable tv provider, and the wiring for cable tv is different than Fiber Optic. Also, I have found several consumer cable modems. I know what kevdog is thinking if Shadowbane is having trouble finding a modem that would work on his local cable provider I don’t he just switch to that Company from Cincinnati Bell. Well the problem with that is while Spectrum does provide similar internet download speeds their max upload speeds are ten times slower, so I am not going to switch. Wait a minute why not purchase a three in one device from Asus, I will address that problem in the next paragraph.

The reason purchasing a three in one device won’t work is running a device in modem only mode isn’t compatible with Cincinnati Bell equipment. A few months ago I talked to a Cincinnati Bell network engineer, and he explained the problem to me. Basically, the equipment on their end can’t communicate with any device that is operating in modem only mode. He suggested instead of messing with a modem only mode to set up my future Pfsense equipment just created a subnet for the Pfsense and have their provided equipment forward all its traffic to the Pfsense equipment.

Which zyxel model do you have? Where does the firber optic network end? – at the wall plate or elsewhere?

I have the Zyxel VMG4381-B10A and I believe the fiber optic end at the wall plate, the wire that connects from the wall plate to the back of the modem is Ethernet 5e.


I dont have the modem to test but googling that model number there are a lot of articles about putting that router into bridge mode. Have you tried that at least?

My ISP too provides dynamic IP with Fiber optic terminated with RJ45, the connection is based on PPOE. I connected that directly to pfsense and configured it for PPoE settings and pfsense works as modem too.

For most type of connection you dont need external modem with pfsense, before trying this method even i was of opinion that we need a modem.

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