Forward the Internet connection to a second router for network management (Bridge vs DMZ)

[ProclaimDragon]

Hi,

For optical fiber, a particular ISP I'm interested in, installs a ONT+Router all-in-one device (Huawei) which does not support bridge mode (maybe the router itself supports it but the functionality was probably removed by the ISP). But I don't like this router, I want to use my own (Asus AC68U) to manage my whole LAN. Usually, one would connect the Huawei to the Asus in bridge mode and have the Asus manage everything. But like I said, there's no bridge mode in the Huawei.

I believe the Huawei supports DMZ and I can redirect all the traffic from the Huawei to the Asus and still have the Asus manage everything. However, my question is, in practical terms, what exactly is the difference between redirecting all the traffic with bridge mode and redirecting all the traffic with DMZ. I'm really looking for practical pros and cons. Like "in mode X you can do this but not that".

Would I be able to achieve what I want - have the Asus manage the Internet connection to my LAN (like NAT, Firewall, Port Forwardin, DDNS, VPN, etc...) - with DMZ? Or is there anything that would only be possible in bridge mode?

[+John Teacake MVC]

What model of Huawei is it? Usually when ISP's do things like this, you find the MAC and clone it onto your own device. That's what I have done in the past with an ISP over here in the UK.

[+BudMan MVC]

The problem with double nat.. For one is a performance hit, be it slight - it still a hit. You prob could have issues with isakmp since this a static port and headers prob going to get messed up in the double nat.  This is used in IKE which is IPSEC vpn connections mostly.. Do you do any of that?  That can make it more complicated, but should still be able to get around it.

Normally you would avoid a double nat as much as possible..  If not in the dmz of the first router it becomes a real pain to control port forwarding, stuff like UPnP would not work.  But if in the dmz you should not have all that many issues other than the slight performance hit of a double nat.  You could have issues with ftp for sure depending on the routers and ftp helpers, if no helper trying to do active or run a ftp server behind could be broken..  Passive could even be a problem if 1st router doesn't have a helper for ftp..  I wouldn't worry about that too much, unless you run a ftp server to the public.. Or use it all the time - its really a deprecated protocol and sftp should be used anyway.

Normally a DMZ is not a bridge, depending on the router it might not forward specific traffic or might do something weird with some ports being listened on the 1st router and not forwarding correctly.  Like I said should be avoided!!!!  But if you have to do it, its not the end of the freaking world.. More than likely you can get everything to work..

Is this a business line or home connection.  Business I would think you could demand bridge mode..Do you plan on playing lots of say console games behind this setup?  Stuff that does with UPnP and or likes static source ports could have problems, but since dmz in first router you should be ok.. For example if console game says via UPnP hey make sure you use source port X on when you nat because who I am connecting too expects that but then outside router just nats it to some random port that is open in its state table.  Where you connecting might say hey that is wrong source port.

Dmz is not the same as actual public IP, the router is doing forwards and napt and ports are going to get changed twice, this could cause issues since while it only done once and depending on the router you could have control over this When you do your specific forwards.  But since its being done twice and outer one is just in auto mode with everything being forwarded to first router..

I would really push for bridge mode on the isp device.  But if a no go, its a slight performance hit..  Why exactly do you want your own router?  To run your wifi, just use it as access point and just use the isp to control forwards, now only 1 nat.  Do you run multiple network segments?  Why do you feel you can not just use the isp device as your edge router?

Another issue that can happen, is just crappy device given by isp and when its doing nat and having to keep track of a lot of connections (p2p for example - especially if multiple users of it) the isp device nat falls down.. But if it was just bridging the connection the user could use a better device that can handle the number of states and not have an issue, etc..

 

 

Edited November 10, 2015 by BudMan

[ProclaimDragon]

What model of Huawei is it? Usually when ISP's do things like this, you find the MAC and clone it onto your own device. That's what I have done in the past with an ISP over here in the UK.

Huawei HG8247H. If by cloning the MAC you mean you'd only use my own device, that will not work. I still need to use the ISP's device for IPTV and VoIP. Also, I believe my credentials are builtin in the device, not sure about this though.

The problem with double nat.. For one is a performance hit, be it slight - it still a hit. You prob could have issues with isakmp since this a static port and headers prob going to get messed up in the double nat.  This is used in IKE which is IPSEC vpn connections mostly.. Do you do any of that?  That can make it more complicated, but should still be able to get around it.

I'm not sure... I want to have the VPN service on the Asus turned on so I can connect to my LAN and access my internal services. I do not want VPN to forward all my traffic through my home connection. I'd like to have the possibility though, but I probably won't use it.

Normally you would avoid a double nat as much as possible..  If not in the dmz of the first router it becomes a real pain to control port forwarding, stuff like UPnP would not work.

For security purposes I usually turn UPnP off and open the required ports as necessary for any games I play (which are not that many to be honest).

But if you have to do it, its not the end of the freaking world.. More than likely you can get everything to work..

I'm afraid I do because the bridge functionality is disabled and I'm not sure anybody has yet found a way to enable it (if the router supports it, I believe it does).

Is this a business line or home connection.  Business I would think you could demand bridge mode..Do you plan on playing lots of say console games behind this setup?  Stuff that does with UPnP and or likes static source ports could have problems, but since dmz in first router you should be ok.. For example if console game says via UPnP hey make sure you use source port X on when you nat because who I am connecting too expects that but then outside router just nats it to some random port that is open in its state table.  Where you connecting might say hey that is wrong source port.

Home. I'm not in a position to demand anything. And the only way to request something is after signing the contract, which makes it worse. AFAIK, they no longer have the old ONT+Router combo available anymore, they install the new Huawei for all new clients. Like I previously said, I prefer to disable UPnP and forward all the needed ports. Do you see any issues with this setup?

I would really push for bridge mode on the isp device.  But if a no go, its a slight performance hit..  Why exactly do you want your own router?  To run your wifi, just use it as access point and just use the isp to control forwards, now only 1 nat.  Do you run multiple network segments?  Why do you feel you can not just use the isp device as your edge router?

Because the ISP router sucks and doesn't have all the features I want. I've read many reviews on the Asus routers and they have exactly what I want and like in a router. It's not just the wifi, it's everything. To name a few, VPN Server, DDNS, dual wireless, QoS and proper IP/MAC management (they usually suck on those ISP routers). Also, the Asus has constant firmware development and there's the excellent Merlin firmware with extra features that I need (for one, DDNS to run a custom script so I can have my own custom domain). I just wanted to delegate the Internet/LAN management to the Asus as much as possible and leave the ISP router for IPTV and VoIP only.

Thanks for the long and descriptive post, that's exactly the kind of answer I was looking for

[+BudMan MVC]

"proper IP/MAC management"

What is this exactly - setting a reservation?  While I agree with you some very limited dhcp servers in many soho routers...  I don't recall seeing one that doesn't do a reservation.  What I have seen is the lack of setting any other options like changing the gateway or dns, or other options you can set with dhcp, etc.

Again double nat would not be the preferred setup, but it is a very workable solution if you don't have the choice.

[farmeunit]

I have a modem with Time Warner that I couldn't get bridged (hidden menu and nothing I could find would get me into it).  I just called them up, asked to be transferred to Tier 2 support, and them accessed it and bridged it for me.  Then I connected my own gear.  Try giving them a call if you haven't.

[ProclaimDragon]

"proper IP/MAC management"

Like, machine A has MAC A:B:C:D and static IP 1.2.3.4 and it's named "My Personal Device (on the router itself) than I can forward ports, control network access and stuff like that per machine identified by the name I previously selected instead of trying to identify the device I want by MAC or IP address. It's very basic but a lot of devices fail having a good interface to manage stuff like this.

I have a modem with Time Warner that I couldn't get bridged (hidden menu and nothing I could find would get me into it).  I just called them up, asked to be transferred to Tier 2 support, and them accessed it and bridged it for me.  Then I connected my own gear.  Try giving them a call if you haven't.

Yeah, I'm gonna try that but unfortunately the kind of technical support we get around here is not very good, they are not very comprehensive. In other words, they really don't care.

[+BudMan MVC]

So that is simple dhcp server reservation..  And then ability to use an alias in firewall rules, etc. That would not really be a reason to use one device over another if you ask me..   . But sure if you like that feature of a firmware then ok..

[ProclaimDragon]

You asked me why I wanted to use my own device and I gave you a few reasons, that's just one of them. But it's certainly not the most important. I wouldn't buy and use my own device just for that.