Configuring multiple routers?

No... that's wrong.

The basic problems are that you have too many routers and probably a wiring problem. I'll assume that you want to use the Airport as the router and DHCP server.

Wire it this way:

WAN LAN LAN WAN(N/C) SB6121 ========= Airport Extreme =============== RP614v2 Modem Base Station =============== PC =============== PC

The trick is to set the RP614v2 to act as a wireless access point (AP) and *NOT* as a router. Note that the WAN (internet) port on the RP614v2 is not connected to anything. I'll assume that your using the default IP address for the Airport Extreme, which is 10.0.1.1. Connect the RP614v2 to a PC directly and go to: http://192.168.0.1 or http://192.168.1.1 which is the default IP for the RP614v2.

Change the following settings. IP address = 10.0.1.2 DHCP server = OFF Wireless SSID = not the same as the Airport SSID Encryption = WPA/WPA2 if available. RIP2 = OFF UPnP = OFF You may need to set a static IP address on the PC in order to access the RP614v2 after changing the IP address and disabling the DHCP server. When done, your RP614v2 is now an AP.

Plug the RP614v2 into the Airport Extreme and check if the ethernet cable lights illuminate at BOTH ends. If not, you'll need an ethernet crossover cable. Both devices should have auto-polarity, so that shouldn't be necessary.

When done, a laptop connecting via wireless to the RP614v2 will have its IP address, default gateway, and DNS servers delivered by the Airport Extreme. Setting the RP614v2 IP address to 10.0.1.2 is strictly to allow for reconfiguration of the RP614v2 if necessary.

Also, be sure to check the DHCP address range of the Airport Extreme. It should be something like 10.0.1.100 - 10.0.1.199 and should NOT overlap any IP addresses that you have assigned statically (such as printers and servers).

Please note that the RP614v2 is in my never humble opinion a lousy wireless router. I've had hangs, erratic disconnects, and general weirdness in the past when I was using them. If you must use it, please be sure you're running the latest firmware.

Thanks for your reply Jeff.

The Airport is far away from the modem and wiring closet. Impractical to run cable(s) to it (again).

Dave

The 614 is not a wireless router. Only Ethernet.

Well here is how I'm handling something similar. The modem feeds the wan input to the wifi/router. Then a switch connects to all ethernet clients and one wire goes from the switch back to the wifi/router.

I hate netgear with passion. Few companies I have allowed to burn me twice. They really suck.

Jeff had made a pretty good argument a few threads ago that you put all your clients on one switch. They come in 5, 8, and 16 ports, etc. The clients can actually use the bandwidth between each other. What you don't want to do is have clients on the wifi/router ethernet port and your switch. From what I recall of the thread, access between the clients on the switch and the few on the wifi/router would get funky.

In my case, I have the wireless set up to be isolated. I don't want them to talk to the wired devices for security reasons or each other for that matter. Essentially I set up a hotspot at home with DD-WRT. You should be able to put the wireless on the same network as the wired if you want.

Buffalo WZR-HP-G450H D-link dgs-2208

My requirements are simple. It has to work without locking up. Nothing pissed me off more than a router in nanoland. The Buffalo comes with DD-WRT on it. Basically it was pretty brain dead once I got past a weird issue with my modem.

One think you need to do is insure the firewall from the modem is not being used. Just declare the wifi/router to be the DMZ. You don't want to double firewall. The wifi/router should do the DNS, not the modem.

Now I have the address of the modem, which itself has a router on it, different than the address of the wifi/router and switch. Like Jeff said, if they are all on the same address then you need to insure there is no conflict. It seems easier to me to put them on different addresses.

That's pretty much how I do it, but I have some low-bandwidth devices that need Internet access so those are connected directly to 100Mb LAN ports on the gateway router rather than wasting ports on the Gig switch.

Do you remember the thread? Bandwidth contention on the link between the switch and router (which is really just linking two switches together) is about the only thing I can think of, but that shouldn't cause any funkiness and is easily worked around by placing the high bandwidth devices on the standalone switch and the low bandwidth devices on the router's LAN ports. That's an extremely common network configuration, which it wouldn't be if it carried funkiness.

He mentioned that he's using a Motorola SB6121 cable modem. To my knowledge, it has no firewall, no routing capabilities, no DNS, etc. It's just a cable modem, not a combo unit. RF on one side, Ethernet on the other side. Think of it as a bridge. The only reason it has an IP address (192.168.1.100) visible from the LAN side is so that you can check it's status.

Sorry, I missed the part where you wanted WIRED ethernet expansion. I also managed to get the RP614v2 and the WGR614 mixed up. Sorry, but that's what happens when I'm talking on the phone when trying to reply to problems.

I'll assume that you have a CAT5 cable between the Airport Extreme WAN port and the Rotomola SB6121 modem. That's a must and can't be replaced easily. You will need to either:

- Relocate the Airport Extreme near the SB6121 and add an additional wireless access point in the current remote location as described in my previous diagram.

- Run RG6/u CATV coax from the wiring closet to somewhere closer to the Airport Extreme location.

- Some other topology. You haven't described your layout so I can't be specific. In any arrangement, you MUST have a cable between the SB6121 and the Airport Extreme WAN port.

Using the RP614v2 as an ethernet switch is basically a bad idea. It can be done, but not worth the effort. What killed your network was that when you plugged into the LAN side, you still had the DHCP server enabled in the RP614v2. Now, with two DHCP servers in your system, your client computers would sometimes gets a 10.0.1.x IP address from the Airport, or a 192.168.0.x address from the RP614v2. That won't work. Replace the RP614v2 with a real ethernet switch.

Putting an ethernet switch BETWEEN the SB6121 modem and the WAN port of the SB6121 is not going to work. Your cable modem provider will deliver exactly one IP address to each customer, which normally goes to the router (Airport Extreme). The first device enabled will grab this one IP address, and everyone else will get a DHCP failure message. The ethernet switch will need to be plugged into one of the three LAN ports on the back of the Airport Extreme.

If you need more detail, please describe the layout and approximate cable distances.

Is there a file server involved? If so, the comments about putting everyone on the same ethernet switch should be considered. In these days of gigabit wire speeds, it's a good idea as daisy chaining

10/100Mbits/sec switches will work, but might also act as a bottleneck. However, if all your client traffic is to/from the internet, almost anything faster than your cable modem connection will suffice.

Also, if you can't run CAT5 between the SB6121 modem and the Airport Extreme router, you can try power line networking (HomePlug) or phone line networking (HomePNA) instead. I don't like these as (despite claims to the contrary), they are slow, unreliable, susceptible to interference, and very sensitive to power line and phone line layout. I have a pair of Netgear XE104 power line modems that I use for testing to see if it might work. The best I've done was about 50 wire feet of power line on the same circuit. If your power wiring at both ends is on the same circuit breaker, it should work. If on different breakers, it might work. If on different phases, toss a coin.

Well I've failed.

No matter what I try (and I've tried all suggestions made here) I get this: in the Netgear RP614v2's connected devices table, a directly-connected iMac shows up, but not the Airport Extreme (in bridge mode). (Yes I power-cycled and refreshed the table after each new configuration.)

I've tried connecting the AE to several different ports on the Netgear, first confirmed by plugging in the iMac.

Cables are not the issue because if I plug the AE (in non-bridge mode) into the cable modem (using the same or a different cable), it works.

I'm telling mgmt. that paying to have a 2nd cable run to the Airport (costly) is the solution. I don't like it but there it is.

I wish I knew enough about the whole IP configuration thing to be able to point to something and say "That is at fault", but it's all a foggy mess (in my head). I know that with experience comes competence, but isn't there a good starting point such as a web-seminar or e-book that can cover the basics and more?

Thanks for all who contributed to the discussion.

Dave

Perhaps this article at Gibson Research about multiple routers will help you understand.

Very clear writing. It distills the details down to a few rules.

Thanks!

His original request said it killed the wi-fi but the cabled Ethernet worked.

So that would be the obvious place to start.

Give the two routers different SSID names and passwords. That way there should be no possibility of their wireless interfering with each other.

Also different IP addresses eg 192.168.1.1 and 192.168.2.1 - even if this isn't necessary it will make it easier to see what is connected to what.

The second router's WAN will be its connection to the first router.

The first router's WAN will be the cable modem and broadband connection.

My Lady Friend's home network is set up this way using an older

802-11G router that supports WEP for her and her room-mate's home laptops, and a newer 802-11N (150Mbps) router for their work laptops which have been configured by their employers not to allow WEP.

I'm off this afternoon. Where do you live? :-) We could knock this out in no time.

Why not dump the Netgear and get a switch? For me, feeding the airport into the netgear on either wan or on the 4 port side is uncharted territory. I mean, yeah, the netgear should act like a switch, but they didn't build it for exclusively that purpose.

Switches are cheap. For the life of me, I don't know why they don't make wifi routers with more than 4 or 5 ports, because invariably with multiple PCs and internet appliances, you quickly run out of ports.

When the dust settles, I'm sure all the clients will be happiest if they are on one switch. [Well assuming what I guess is for small office that this is feasible physically. I think working backwards from the plan that all clients sit on the switch is the way to go.

The switch is kind of dumb. It takes its orders upstream. I have never had to program a switch for the very simple home networks I have set up. You just plug them in and they do magic.

So it would go Googlerola modem wherever the cable outlet is installed. Then Airport in the office in a central location. Modem feeds the wan input. As Char indicated, the modem doesn't have a firewall, i.e. behave like a one port router. [That is one headache removed.] One port of the switch goes to one port on the Airport. All clients go to the switch.

Incidentally, I have never heard anything good said about those Airport routers. Since you are posting on the UK forum and guessing you are there, you probably don't hear Leo Laporte's Tech Guy radio show. He is a total Apple fanboi, but suggests staying away from the Airport routers. Frys (our local electronics store) suggests Apple users avoid Airport, and if they do get an Airport, they suggest professional installation. This myth that Apple makes things easy is just that, i.e. a myth.

I have to say I really like DD-WRT, which my Buffalo uses as one of two firmwares you can run. There are so many posts on the net about set up that you can usually solve your problem in a google search. Otherwise you need to find a forum of users for your particular router, which is a smaller audience.

Worse of all, the manufacturer after a while simply stops updating the firmware. Why support old hardware when you can sell new hardware! I had to quit using a rather expensive Linksys router because Cisco got caught up in a GPL violation on the firmware and had to stop providing let alone fixing bugs in the firmware. You go to the support page and all they can do is give you the manual. DD-WRT is the way to go.

On the TWIT network, Steve Gibson is known as the "explainer in chief."

On an awful lot of my small consulting jobs, wireless routers get specified for installation just to future-proof things a bit, even when another kind of hardware might be a slightly better fit. I don't shy away from those situations. It's just too common to ignore.

A wireless router is the obvious choice if they need a wireless router, but sometimes they need a wired router, so we disable the wireless portion. Sometimes they need a small switch, so we bypass the router and wireless portions and make the few necessary config changes to turn it into a switch. Sometimes they just need an access point, so again, we make the few necessary config changes and go. The same goes for a wireless bridge...use a wireless router instead of a device labeled as a wireless bridge, saving money and keeping future options open.

Wireless routers are nearly as cheap as switches, as cheap as wired routers, and cheaper than access points and bridges, so not only does it frequently make financial sense to choose a wireless router over a more dedicated piece of hardware, but if their needs change in the foreseeable future, before enough time has passed to make the technology obsolete, they can just reconfigure the wireless router to make it fill an entirely different role. It wouldn't surprise me if, one of these days, a client said they needed a DHCP server and we'd fill the requirement by connecting a wireless router that does nothing but DHCP.

Unmanaged switches don't need to take orders. They know how to do their work without supervision.

I like dd-wrt, as well. I have it installed on all of my own "routers" scattered around the house and office. (Routers in quotes because all but two aren't actually doing any routing. The rest are acting as access points, wireless bridges, and switches, but all started out in life being called a wireless router.)

I agree with all except switches are way cheaper than wifi routers, at least in the US. Especially on a cost per port basis. Plus I haven't seen any wifi routers with more than 5 ports, and most are only 4.

Most people have a desktop and notebook. In the US, the average household size is 2.5. It doesn't take much to use up the 4 ports. Throw in a NAS, and you have hit the wall.

I acknowledged the price difference, but a wireless router can do everything that a switch can do, while the reverse isn't true. Sometimes that matters, sometimes not.

Agreed, but it's drop dead easy to plug in one or more additional switches, when additional ports are needed. Besides, a lot of new networking hosts are wireless these days, from TV's to BluRay players to of course portable devices like laptops, netbooks, tablets, smartphones, etc., so wired ports sometimes aren't quite as needed as they once were.

If you haven't managed to sort this yet, then there is possibly another way without you having to lay another cable.

This is assuming the connection between the Comcast modem and the AirPort is 10/100 and is not using PoE

Simply use a CAT5 Economiser like this both ends of the cable

Connect the A port one end to the Comcast Modem, and the other A port the other end to the AirPort

connect the LAN Ethernet side of the Airpoint to the B port, and a simple network switch to the B side near the Comcast modem.

If you like, you can use the Netgear as a switch by just disabling the DHCP server on it, and connecting to one of the LAN ports, just ignore the WAN port on this.