1 cable modem, 2 routers, 2 unconnected networks

[RandallX]

I have been trying to figure this beast out, been all over with no luck. Checked through the posts here, but didn't find anything exactly like I want to do. So please bear with me if I missed the answer buried in the forums elsewhere.

As stated in the title, I have a cable modem in my home office (at one end of my home) and a Netgear WNDR3700v4 router connected to it. I am using the wired main network for my office computers and a remote music server out in the living room. I also have an external drive connected to the USB port on the router, but it is slow as hell. The Guest wifi network is for my wife, and our mobile devices and the Roku 3 (wifi connected currently) in the living room and is disconnected from my main network for security reasons. I am extending the guest network with a Netgear N300 wifi extender. But it doesn't reach the far end of our home and the Roku3 has poor connectivity and drops the programs we watch fairly often.

So, my question is. Can I attach two routers to one modem and have 2 distinct and separate networks? If I can, how does one accomplish this? Do I need a switch between the routers and the modem? Specifics would be excellent. I am -fairly- knowledgeable about networking but it really isn't my specialty..

I was looking at the new Nighthawk X4 AC2350 routers from Netgear as well. A much faster NAS (USB 3.0) would be nice. Would the range from one of these cover my entire house which is about 50 feet from one end to the other?

My quest is to have my main office computers (3) and my music server and NAS all on the main network. A separate wifi network (which -could- be the guest network from the same router or a different network from a second router) for my wife and the mobile devices, and a wired ethernet connection for the Roku 3 that is part of the secondary network.

I have been working on this for a bit now and the wife is getting impatient, I am getting frustrated, the cats are laughing at me and ... well you get the picture. Any help anyone can throw at me would be appreciated. The more detailed the better. Many, many thanks in advance..
Cheers
Randall

 

[CaptainSTX]

No way to know if a new router's WiFi coverage will be better than what you have. WiFi depends on many factors so your best option is to try and if necessary return the new router.

You should also look at powerline or MOCA adapters for your ROKU.

The best way to have two routers and one modem is to double NAT the second router behind the first primary router.

IMHO double NATed routers give you more security and control than guest networks.

When set up correctly double NATed routers do not degrade performance. I would use the newest and most powerful router as my primary router then your older router as your secondary router. Also if you add a NAS to your network be sure to connect it to a LAN port on the network segment where most of the traffic to and from the NAS will be.

 

[thiggins]

So, my question is. Can I attach two routers to one modem and have 2 distinct and separate networks? If I can, how does one accomplish this? Do I need a switch between the routers and the modem? Specifics would be excellent. I am -fairly- knowledgeable about networking but it really isn't my specialty..

Sure can. An oldie
How To: One Internet connection - Two Private LANs

Stay away from the AC2350 routers for now. They are not fully baked. At any rate, they don't improve range. They are focused on providing higher throughput to a class of devices that don't yet exist.

 

[RandallX]

Thank you, Gentlemen...
Appreciate the responses from both of you.
I think the second approach that Thiggins put forward is probably more of what I am looking for. Much thanks to you, sir!
I will give this a try. If I run in to any snags... well, I just might have to keep this thread alive!

Cheers to you, my friends..
Randall

 

[Crabsalad]

Hello thiggins,

I want to create two separate networks as in this guide but what is that switch brand, model?

I have two netgear routers for this project but need guidance on the switch to be connected to the internet modem.

Thanks

 

[drinkingbird]

Hello thiggins,

I want to create two separate networks as in this guide but what is that switch brand, model?

I have two netgear routers for this project but need guidance on the switch to be connected to the internet modem.

Thanks

The thread is almost 10 years old so I'm sure there are newer and better switches. In reality it has to be a router connected to the modem, unless your ISP happens to allow more than 1 device (in the US, none of the major ones do).

The easiest solution is just to daisy chain two routers. One connected directly to the internet, then the LAN of that connected to the second router. First router serves one of your networks, second serves the other. You can then put some firewall rules in the second to block access to the stuff on the first and only let it hit the internet (it can also be done with a dummy static route on the second router too).

 

[coxhaus]

The thread is almost 10 years old so I'm sure there are newer and better switches. In reality it has to be a router connected to the modem, unless your ISP happens to allow more than 1 device (in the US, none of the major ones do).

You can use a switch connected to the modem if you have more than one IP address. I had a friend that paid AT&T for 5 static IP addresses many years ago. I have also heard of people having 2 IP addresses so they can run more than one router if they choose to.

 

[drinkingbird]

You can use a switch connected to the modem if you have more than one IP address. I had a friend that paid AT&T for 5 static IP addresses many years ago. I have also heard of people having 2 IP addresses so they can run more than one router if they choose to.

Yes, you have to sign up for business class service and pay for static IPs, fraction of the speed and double the price. I doubt that is what is being discussed here.

In the US on residential service you get 1 device/1 ip address, unless you have some small local ISP, and even then it would be unlikely.

When you do get business class with static IPs very often they force you to use their router, that's how it is with Comcast. FIOS lets you use your own but says they won't support it, so when I had it I kept their router on a shelf just in case I needed to toss it in when calling for support.

 

[coxhaus]

Yes, you have to sign up for business class service and pay for static IPs, fraction of the speed and double the price. I doubt that is what is being discussed here.

In the US on residential service you get 1 device/1 ip address, unless you have some small local ISP, and even then it would be unlikely.

When you do get business class with static IPs very often they force you to use their router, that's how it is with Comcast. FIOS lets you use your own but says they won't support it, so when I had it I kept their router on a shelf just in case I needed to toss it in when calling for support.

AT&T knows whether your property is residential or business. He had 5 statics at home.
You can test your service by adding a switch to your modem and plugging in 2 routers. If they both receive IPs then it will work. In the real old days they made "business routers" which handled 5 internal IP addresses. I think they fell out of favor.

 

[drinkingbird]

AT&T knows whether your property is residential or business. He had 5 statics at home.
You can test your service by adding a switch to your modem and plugging in 2 routers. If they both receive IPs then it will work. In the real old days they made "business routers" which handled 5 internal IP addresses. I think they fell out of favor.

I had business class service at my home for a decade. It is the only way to get statics from the vast majority of ISPs. Was the case with both Comcast and Verizon for me. No AT&T here so it is possible they will sell you more IPs (probably not static though) on residential service, but it is something you'd have to specifically order and pay for. Comcast's static IPs are tied to the modem/router combo they provide you, it is in the config file that gets downloaded to it, so you can't use your own router unless behind it in a double NAT setup (which is how I ran it). They would not support static IPs with the router in bridge mode.

If you have a straight, plain modem, there's about a 99% chance that the second device will get no IP. If you have a router from the ISP, sure it'll work fine, it will just pass out internal IPs and NAT them. Sure, give it a try, likely a waste of time though.

 

[tgl]

I had business class service at my home for a decade. It is the only way to get statics from the vast majority of ISPs. Was the case with both Comcast and Verizon for me.

Yeah, that's true for Verizon for sure --- in their residential service, not only do you not get static IPs but the TOS forbid running any kind of server so there'd be little point in a static address anyway.

I just signed up for Verizon's business FiOS service for my new abode: 1Gbps FiOS service with 5 static IPs (and no TOS restrictions) for $289/mo. That compares to $137/mo for 1Gbps residential FiOS at my soon-to-be-ex residence on the other side of town. Yeah, expensive, but on the other hand there's no SLA at all on the residential service. Ask me in a year or two whether the actual reliability is any better.

BTW, the specs on the CR1000A router they gave me are pretty eye-catching. 10Gbps WAN port, one up-to-10Gbps LAN port and two up-to-2.5Gbps LAN ports, wifi 6E with 4x4 radios on all three bands. It won't need to be replaced if/when they offer more than 1Gbps fiber service, which I suppose is coming. Sadly, it's pretty lacking feature-wise, eg no VLAN support as far as I can find from the manual.

 

[coxhaus]

He had 5 outside static IP addresses owned by AT&T but they were not private IP addresses. I know I as helped him work on his network. He did pay extra for the IP addresses.

If you have a straight, plain modem, there's about a 99% chance that the second device will get no IP. If you have a router from the ISP, sure it'll work fine, it will just pass out internal IPs and NAT them. Sure, give it a try, likely a waste of time though.

This is non-sense saying you get private IP addresses out of router. It does not relate to outside static IP addresses.

 

[drinkingbird]

He had 5 outside static IP addresses owned by AT&T but they were not private IP addresses. I know I as helped him work on his network. He did pay extra for the IP addresses.

This is non-sense saying you get private IP addresses out of router. It does not relate to outside static IP addresses.

You're both confusing and misunderstanding my statements.

If you have residential service and aren't paying for extra IPs (which you usually can't even do with residential service), it is extremely unlikely plugging two devices into a straight modem will work. If it is a modem/router combo, obviously it will work, but they will be private IPs just like any other router (including your own) would hand out.

 

[drinkingbird]

Yeah, that's true for Verizon for sure --- in their residential service, not only do you not get static IPs but the TOS forbid running any kind of server so there'd be little point in a static address anyway.

I just signed up for Verizon's business FiOS service for my new abode: 1Gbps FiOS service with 5 static IPs (and no TOS restrictions) for $289/mo. That compares to $137/mo for 1Gbps residential FiOS at my soon-to-be-ex residence on the other side of town. Yeah, expensive, but on the other hand there's no SLA at all on the residential service. Ask me in a year or two whether the actual reliability is any better.

BTW, the specs on the CR1000A router they gave me are pretty eye-catching. 10Gbps WAN port, one up-to-10Gbps LAN port and two up-to-2.5Gbps LAN ports, wifi 6E with 4x4 radios on all three bands. It won't need to be replaced if/when they offer more than 1Gbps fiber service, which I suppose is coming. Sadly, it's pretty lacking feature-wise, eg no VLAN support as far as I can find from the manual.

The reliability won't be any different, but the same day SLA was a nice perk. Luckily, I never had to use it. I've had FIOS (both business class when I ran my own servers and now residential) for over 10 years and I can think of maybe 2 outages that happened at 3AM which I'm assuming were for maintenance.

When I moved my servers to hosting around 5 years ago was when cellular hotspot started becoming feasible for work VPN use (on 3G it was too slow and the VPN disconnected frequently, LTE made that much better) so I downgraded to residential, as if I had to survive off cellular for a day I could. My 300/300 FIOS is $30/month. 1G residential here with router included I think is $90 per month (without router used to be $70 but that plan has disappeared, they're trying to force you to rent the router by building it into the price now). I have no need for 1G though, 300 is plenty. Back when I had business FIOS I think it was 50/50 with 1 static for 70 or 80 per month.

I remember many years ago when I had verizon DSL they actively blocked incoming port 80 so I had to use my dynamic DNS service's redirect feature to send people to port 85 or something. That was when I was just running servers for my own use. Surprisingly they did not block port 25 in either direction so my mail server was fine. Not sure if they do similar on FIOS or not. Comcast also had TOS against running servers but I did it with DDNS for years until someone using my wifi was infected with a spam bot and sent a ton of port 25 traffic out. Their security team noticed and put a port 25 and 80 block on me, at which point I finally had to cough up for static IP and business class. But at that point I was in need of it anyway.

 

[tgl]

The reliability won't be any different, but the same day SLA was a nice perk. Luckily, I never had to use it. I've had FIOS (both business class when I ran my own servers and now residential) for over 10 years and I can think of maybe 2 outages that happened at 3AM which I'm assuming were for maintenance.

I do have to say that residential FiOS' reliability has been great since I upgraded to 1Gbps service about 2 years ago. Before that I had a monstrously large ONT box dating from 2010 or so, which froze up every couple of months and required a complex disconnect-and-reconnect-the-battery-backup procedure to reboot. Don't miss that. The ONT in the new install looks to be the same little black box as I have in the residential 1Gbps setup, so I'm optimistic about its reliability.

 

[drinkingbird]

I do have to say that residential FiOS' reliability has been great since I upgraded to 1Gbps service about 2 years ago. Before that I had a monstrously large ONT box dating from 2010 or so, which froze up every couple of months and required a complex disconnect-and-reconnect-the-battery-backup procedure to reboot. Don't miss that. The ONT in the new install looks to be the same little black box as I have in the residential 1Gbps setup, so I'm optimistic about its reliability.

I still have the original big white one, has never given me a problem. I run it off my UPS though, ditched the internal battery since it only backs up internet for 2 mins. Maybe you had a dud one.

 

[tgl]

I still have the original big white one, has never given me a problem. I run it off my UPS though, ditched the internal battery since it only backs up internet for 2 mins. Maybe you had a dud one.

Yeah, mine could've been a lemon -- hard to be sure with only one data point. Agree about the UPS; I ran mine the same way. (From memory, mine kept up internet service for 10 min not 2 by itself, but still not nearly enough. Power outages of a few minutes are common round here.) The one negative of Verizon's new smaller ONTs is that there's no battery in them at all; but that just reinforces that you should bring your own battery backup.

 

[drinkingbird]

Yeah, mine could've been a lemon -- hard to be sure with only one data point. Agree about the UPS; I ran mine the same way. (From memory, mine kept up internet service for 10 min not 2 by itself, but still not nearly enough. Power outages of a few minutes are common round here.) The one negative of Verizon's new smaller ONTs is that there's no battery in them at all; but that just reinforces that you should bring your own battery backup.

For a while I used their battery and if internet was down for more than a couple mins ran an extension cord from my UPS. There was a hack for the big white one where you could splice a couple wires and it would run internet until the battery died, but I didn't want to mess with that. Eventually the internal battery went bad and they make you pay for the replacement, so I finally ran an outlet from my UPS through the attic down to the ONT. As long as my desktop is asleep or off, it backs up my switch, router, and ONT for 8-10 hours, and have never had an outage that long.

I just got a free Smart UPS 750, much less runtime but plenty for what I need. Unfortunately the batteries are down to about 50% runtime and prices are sky high right now. So sticking with the 20 year old Smart UPS 1400 for a while. Main issue with the old one is it draws 10-20 watts just keeping the rectifier and float charging circuit running, and the rectifier has gotten a bit louder over the years making me wonder when it will finally give up. The new ones have all gotten much more efficient, the 750 draws like 3-5 watts when the batt is fully charged and has network management built in too.

Then there is the insane backups RS (simulated wave) that takes 6 batteries and has massive runtime. But the batteries are all dead, would cost more than I paid for it to replace them right now, and I don't like using simulated wave on sensitive electronics. Can run a floor lamp with LED bulb all day though.

Too many UPSes laying around The LiFeP04 based power stations like EcoFlow are coming down in price and adding line-interactive UPS functionality (switchover time is still a bit too high and they don't tell your PC to shut down yet) so keeping an eye on those before I invest any more in batteries for these ones. I think in a year or two those will obsolete these SLA based UPSes. APC's lithium ones are crazy expensive but they'll probably start switching over the cheaper ones soon to stay competitive.

 

[coxhaus]

You're both confusing and misunderstanding my statements.

If you have residential service and aren't paying for extra IPs (which you usually can't even do with residential service), it is extremely unlikely plugging two devices into a straight modem will work. If it is a modem/router combo, obviously it will work, but they will be private IPs just like any other router (including your own) would hand out.

I am confusing you are just not listening to what I said. My friend had a modem only from AT&T no router with 5 IP static Outside IP addresses.

 

[drinkingbird]

I am confusing

Agreed

you are just not listening to what I said. My friend had a modem only from AT&T no router with 5 IP static Outside IP addresses.

Never disagreed that was possible for an extra fee. Some ISPs require you to use their router when you purchase extra IPs. Not all. Comcast does, FIOS doesn't. Apparently AT&T doesn't either.

However if you aren't paying for extra IPs or static IPs there is almost no chance you'll be able to connect a second device directly to the modem (or via a switch).