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Solved Double NAT fix?

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macster2075

Very Senior Member
Very noob question and I know the common answer is... "you can, but make sure to have them on different subnets".

What I am trying to accomplish is to remove double NAT. My ISP modem/router does not have the same features or options as my Asus router, therefore I want to use the Asus, but stay on the same network as the ISP...hence eliminate double NAT.
So, can I have my ISP modem hand out IPs from 192.168.1.1 - 192.168.1.3
and my Asus router 192.168.1.4 - 192.168.1.254?

Will there be any conflicts?
 
Well I don't have all the information but I imagine several solutions! I don't know what you want! put servers on the INTERNET or a NAS etc ....... I'm new to that too! First simple answer is: Put your ISP router / modem in bridge mode and connect your ASUS router to it I believe it will eliminate. Simple, it is only you to enter the config of your modem (it has to be the modem, not the router) and put it in "bridge" mode instead of "PPoE" or "dual stack". In bridge mode the modem disconnects his network and starts to work only as a "bridge", leaving all the network work for the router to do, and thus ends the double NAT problem Depending on the situation, you can do a "port redirection" between NATS.
 
Well I don't have all the information but I imagine several solutions! I don't know what you want! put servers on the INTERNET or a NAS etc ....... I'm new to that too! First simple answer is: Put your ISP router / modem in bridge mode and connect your ASUS router to it I believe it will eliminate. Simple, it is only you to enter the config of your modem (it has to be the modem, not the router) and put it in "bridge" mode instead of "PPoE" or "dual stack". In bridge mode the modem disconnects his network and starts to work only as a "bridge", leaving all the network work for the router to do, and thus ends the double NAT problem Depending on the situation, you can do a "port redirection" between NATS.
My modem has the bridge mode option, but I cannot do that because I work from home, so the work computer (laptop) is the only device connected to the ISP modem.
If I enable bridge mode, then I will not be able to provide internet to the Asus router due to only one LAN port becomes available on the ISP Modem.

I could get away with connecting the work computer via wifi to the Asus router, but I need to be connect via Ethernet because I make phone calls through the internet so I need a stable/solid connection.
The Asus router is in another part of the house connected to the ISP modem via Powerline Adapter which works great, but it does not work good for VOIP.

I've been looking online and some places say this can be done, others say it can't.. so I am confused.
The whole dhcp issue is to avoid conflicts, so I thought as long as the IP range is split between the two DHCP servers it was going to be ok...but, that's why I am here asking the pros LOL.
 
Very noob question and I know the common answer is... "you can, but make sure to have them on different subnets".

What I am trying to accomplish is to remove double NAT. My ISP modem/router does not have the same features or options as my Asus router, therefore I want to use the Asus, but stay on the same network as the ISP...hence eliminate double NAT.
So, can I have my ISP modem hand out IPs from 192.168.1.1 - 192.168.1.3
and my Asus router 192.168.1.4 - 192.168.1.254?

Will there be any conflicts?
You could possibly do this if you disable the firewall on the asus router. leave the ISP firewall turned on and Turn off DHCP assignments from the ISP modem/router to insure the asus router is the only DHCP server handing out addresses.
 
You could possibly do this if you disable the firewall on the asus router. leave the ISP firewall turned on and Turn off DHCP assignments from the ISP modem/router to insure the asus router is the only DHCP server handing out addresses.
I need the ISP DHCP enabled because that is the modem/router that provides an IP to the work computer.
 
can you elaborate what that is?...sorry, Im pretty new at this. Is that a configuration on the ISP modem/router or on the Asus?
you have to look at where your DHCP options are and see if it allows for you to define a manual assignment. I would say check with your ISP modem since the client resides on that side of the DHCP.
 
you have to look at where your DHCP options are and see if it allows for you to define a manual assignment. I would say check with your ISP modem since the client resides on that side of the DHCP.
could this be it?

Capture.PNG
 
Running double NAT on my Asus for years without a problem... so if you do not succeed, do not be worried...
 
My modem has the bridge mode option, but I cannot do that because I work from home, so the work computer (laptop) is the only device connected to the ISP modem.
If I enable bridge mode, then I will not be able to provide internet to the Asus router due to only one LAN port becomes available on the ISP Modem.

I could get away with connecting the work computer via wifi to the Asus router, but I need to be connect via Ethernet because I make phone calls through the internet so I need a stable/solid connection.
The Asus router is in another part of the house connected to the ISP modem via Powerline Adapter which works great, but it does not work good for VOIP.

I've been looking online and some places say this can be done, others say it can't.. so I am confused.
The whole dhcp issue is to avoid conflicts, so I thought as long as the IP range is split between the two DHCP servers it was going to be ok...but, that's why I am here asking the pros LOL.
Can you set a dmz ip with your modem in firewall. If so try to set it to the asus ip.
 
Double NAT does not create problems unless you want to run a server on the double NATed router.

You can not measure any increase in latency or reduction in speed. I have also run double NATed for the past five years and no issues.
 
Nobody answered the original question about IP addressing:

@macster2075 The key is to have different network addresses for the two networks. For the internal network controlled by your Asus, set it to 192.168.50.0/24
Or, really, any network other than 192.168.1.0/24, the reason I pick 192.168.50.0/24 is that my Asus came with that as it's default, if yours does as well you have no problems, I've run 2 routers that NAT in series for years, it's not a problem.

This will make sure the Asus 'understands' when to move packets to the network controlled by your ISP router, and when to keep packets internal.

Good luck.
 
Nobody answered the original question about IP addressing:

@macster2075 The key is to have different network addresses for the two networks. For the internal network controlled by your Asus, set it to 192.168.50.0/24
Or, really, any network other than 192.168.1.0/24, the reason I pick 192.168.50.0/24 is that my Asus came with that as it's default, if yours does as well you have no problems, I've run 2 routers that NAT in series for years, it's not a problem.

This will make sure the Asus 'understands' when to move packets to the network controlled by your ISP router, and when to keep packets internal.

Good luck.
This is basically the way I have it now.. ISP modem is 192.168.254.1 and the Asus router is 192.168.1.1... It's been working fine, but the reason I want to get rid of double NAT is because my son plays online games. I've seen on the internet something about being able to have 2 DHCPs on the same subnet as long as they set to different scopes... meaning
one DHCP for 192.168.1.1 - 192.168.1.3 and another to 192.168.1.4 - 192.168.1.254.
 
This is basically the way I have it now.. ISP modem is 192.168.254.1 and the Asus router is 192.168.1.1... It's been working fine, but the reason I want to get rid of double NAT is because my son plays online games. I've seen on the internet something about being able to have 2 DHCPs on the same subnet as long as they set to different scopes... meaning
one DHCP for 192.168.1.1 - 192.168.1.3 and another to 192.168.1.4 - 192.168.1.254.

Do you actually have a problem?

It sounds like you
- read something on the internet
- thought there maybe a problem, though there isn't any evidence of it
- and are now asking about ip addressing to solve the 'potential' problem above.

There really is no reason to run 2 DHCP servers, and it's not going to solve your issue, DHCP is easily dealt with using one system to assign addresses, you don't need two.

While there is nothing wrong with splitting the address assignment, you're just adding complexity. You're better off keeping it simple.
 
Correct.. there is really no "problem"... it's just that on my son's games it tells him he doesn't have open NAT which I've heard/read is not the best for online gaming....but if you're saying it's not an issue, then I won't worry about it haha. - so I guess Im gonna set this one as SOLVED!
Thanks guys!
 
I'd agree with the comments above, don't try to fix a problem that doesn't exist.

Also, your proposed solution makes no sense. You are mixing up DHCP, NAT and subnets as though they were the same thing, they are not. Having a 192.168.1.x network on both the Asus' WAN and LAN sides is not valid and the router will not accept it.
 
Strict nat is a problem if you cant connect to games on multiple consoles due to closed nat. Open nat also helps in connectivity since you can join wider spectrum of players. By this i mean game will choose you as a host of a game more often than others because of nat. There is a graph that shows that strict nat can only play with people that are open nat moderate nat with people with open/moderate and open with everyone. If you are not comeptitve gamer and you do not have multiple consoles in home then there is nothing to worry about. In case you want to get open nat then you need to call your isp to change ur modem operation to bridge and your router has to support fullcone nat there is no other way to get open nat.

Happy New Year
 
That's great.. I really like this forum.. I get great help and the patience to deal with a rookie like me is fantastic.. I know it's not easy to try to explain/deal with a clueless user haha. But, I really appreciate it!
 

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