What's new

ISP Private IP creates dual WAN IP conflict

  • SNBForums Code of Conduct

    SNBForums is a community for everyone, no matter what their level of experience.

    Please be tolerant and patient of others, especially newcomers. We are all here to share and learn!

    The rules are simple: Be patient, be nice, be helpful or be gone!

OOo

Regular Contributor
I am in Mexico using ISP Izzi.
They use Private IP's. Said another way, my external public WAN IP is not the same as what my Asus route says is my WAN IP. As a result I cannot use VPN or even create a DDNS account.

I called ISP and they said I need to pay for a Static IP ($35 a month)

However, I remember 15 years ago that @Home (remember them) would say the exact same thing. But then you would ask them to make the dynamic IP address discover-able and then they would click a button and it was done.

I am having a tough time believing an ISP in this day and age would use Private IP's?

Also, I see there is a problem with the latest DD-WRT 3.0.0.4.380_7378 firmware related to

"The WAN IP is not the external IP. External IP-based services will not work."

I am lost as to what is going on and not speaking spanish, being in a foreign country is really making things difficult.

Any thoughts? Is this Private IP real and there is no getting around it other than buying a Static IP?

thanks
 
Last edited:
If you connect directly to the modem and go to https://ipleak.net what does it report your IP address?
 
If you connect directly to the modem and go to https://ipleak.net what does it report your IP address?
Ipleak.net reports it as
187.254.149.243

Asus 68R reports the following:
WAN IP: 10.119.98.236

I get the blinking yellow exclamation point on Asus router which states:
The WAN IP is not the external IP. External IP-based services will not work


The supplied Modem/Router is Arris TC862. I placed it into Bridge Mode, restarted and all that.
 
If it's truly in bridge mode you should be able to connect your computer to LAN1 on the modem and see if your computer gets an IP similar to the one reported by ipleak. If it does, then reconnect it to the WAN on the router and reboot the router. You may need to turn off the modem for 5-10 minutes and then power it back up. Make sure you haven't cloned the MAC address of the modem to the Router.

Based on some googling you:
1. Might need to disable the firewall and DHCP on the Arris.
2. Might need to contact Izzi and have them put the modem into bridge mode.

Right now you're getting a local DHCP address assigned by the Arris modem.
 
Thank you for helping. I am pulling my hair out, it is like I have been transported back in time 15-20 years.

I did disable the firewall and DHCP on the Arris.
I also contacted ISP, Izzi and asked for them to put into Bridge Mode. I placed it in Bridge mode myself but didn't get expected results. They said they could not do this and I need to get a Static IP address or I need "to seek the advice of a trusted technician". I swear I am chatting to a computer/AI. I have chatted with about 8 support people and literally get same answers.

It seems like Izzi ISP use Private IP addresses. In which case I think I am screwed for things like cameras, remotely controlling my Asus, VPN, etc.
 
The latest support guy said this to me minutes ago. It is translated from spanish. This person seems to know a bit more and never once told me to pay for a static IP address.

He said the following:

"In your router you need to configure with another ip to generate a subnet and has its ip wan"
"
In this case not because you want to generate a subnet"

"So it has to do with your trusted technician to help you generate the sub" (Zirescu, I think he might be referring to you!!)

I asked the following: So I can get the Arris to pass me the external WAN IP rather than an Arris generate WAN IP?

Not the ip of us can not be modified

With its separate router can do the modification of ip

To generate the subnet

Yes but you must configure the same as the gateway and you can change the IP on your router

I asked: So you believe that I should be able to have the Arris pass me (to my router) the External WAN IP address?

Again I tell you what no change is the gateway so you can receive and send packets so you can modify your router with the IP and that configuration should be done by your trusted technician to generate the subnet
 
You've got the LAN1 port from the modem connected to the WAN on the router? Also did you try connecting your computer directly to the LAN1 of the Modem to see if you get a WAN IP address? You'll likely need to reboot your PC after connecting it directly to the modem. There is a DDNS script that can be used in a double-nat scenario. https://www.snbforums.com/threads/double-nat-custom-ddns-script.34431/
 
Sorry, yes I hooked modem LAN1 directly to laptop, power cycled both, and got a similar IP 187.254.151.156.

I am now back to LAN1 Modem to Asus WAN plug.

I guess I should try that double NAT script. Not real familiar with how to install these scripts but it should be easy enough I would think.

Thanks for sticking with me on this and finding that script!
 
When you connected the laptop to LAN1 on the modem, did the laptop pull the 187.254.151.156 IP? I'm thinking it may have as you got a new IP. If that's the case you could clone your MAC address from the laptop to the WAN on the router. It should then pull the same IP address as what the laptop got.
 
When you connected the laptop to LAN1 on the modem, did the laptop pull the 187.254.151.156 IP?
YES.
MAC Clone: I hooked modem LAN 1 back to Asus WAN port. I went into the Asus and clicked MAC CLONE button. Interestingly the laptop MAC Address was already pre-filled in when I went to the screen. I clicked the MAC ClONE button and hit apply. Didn't see anything change and was still getting double WAN. At that point I powered down modem, router, and computer, waited 10 minutes then powered up Modem, then Router, then Laptop. Logged in to router and still see double WAN issue. The modem still appears to be assigning the WAN IP to Asus (10.119.98.236) when in fact the external WAN IP is 187.254.154.147

To recap, the modem is in bridge mode.
On the modem, it won't let me turn off the WAN DHCP. When I try it says to put in a Static IP. I looked this up when I originally placed the modem into Bridge Mode. A mexican guy had a youtube video how to bridge. People brought up that the modem all of a sudden was asking for a static IP when attempting to turn off DHCP. He said it was a firmware change but does not affect bridge mode.
There are 3 settings on the modem: Bridge, Routed with NAT, and Routed without NAT. (just bringing this up)

Any thoughts? Should I try that double NAT script? thx

 
When you're checking with the laptop you would need to look at the what the laptop was assigned as just bringing it up in the browser would still report the WAN of the Modem.

No - you don't want to turn of DHCP on the WAN of the modem, just the LAN. If you had bought a static IP address then you would disable it and put in the information provided by the ISP.

You could try one of the other LAN ports to see if it gives you the WAN IP. Sometimes there is an option to specify which LAN port is the bridging port. Might be a hidden option which would require looking at the html source, but likely someone would have posted that in the internet. Routed without NAT will still leave you in a Double-NAT situation.

You might be stuck trying the double-nat script.
 
When checking what the laptop was assigned should I be looking at ipconfig/all or the network adapter details?
I actually did check the network adapters and I was given 10.119.64.1 when I was connected to the modem directly. I guess that suggests that the modem continues to assign me something other than the actual external WAN???
I don't think this matters but when I was connected to the Asus I had 192.168.3.146 (note I set my asus router to be 192.168.3.1 as opposed to standard 192.168.1.1).

In the morning I will try all the ports.

thx
 
Yes, ipconfig /all will give you the IP assigned by the modem. When connected to the ASUS you would pull the DHCP IP from it while it's configured as a router.
 
Similar threads
Thread starter Title Forum Replies Date
J trace route shows private IP range after router Other LAN and WAN 3

Similar threads

Latest threads

Sign Up For SNBForums Daily Digest

Get an update of what's new every day delivered to your mailbox. Sign up here!
Top