Tuesday, August 17, 2010

Netgear WNDR3700: Let Me Repeat Myself, Wirelessly

After getting round to replacing our aging home PC late last year, I finally decided to tackle the next step in upgrading our home network, namely upping the transmission speed to 1 Gig. Thanks to the - fast growing - store of digital images we collectively produce, moving those things around really does take up an awful lot of bandwidth and our old Buffalo router only supported 10/100 Ethernet. Therefore, downloading from storage cards and saving the results to a network-attached drive was getting pretty painful, especially now I'm using 16 Gbyte CF cards!

In order to allow for future expansion, I opted for the NETGEAR WNDR3700, dual-band 2.4/5 Ghz unit, largely because it offered simultaneous dual-band support and wireless repeating, the latter being key because I wanted to extend the wireless aspect of the network out to the garage. In order to keep things simple, I bought two of them, largely to make sure that the wireless repeat function should operate flawlessly, free of any weird incompatibilities that might result from using dissimilar devices. (Yeah, I know it's a standard protocol these days, but experience tells me that madness lives down the road you travel by believing "it should just work, sir".)

I'll spare you all the extended tale of woe resulting from what I thought should be a simple half-hour job, but suffice it to say that a) the documentation for wireless repeating mode set-up for this unit is pretty much non-existent, b) configuring the two routers to play nicely together uncovers a number of limitations I wasn't aware of going-in and c) I may yet give up and run a cable from the router to the repeater because of poor end-to-end performance. Anyway, for those of you who want to try the same thing, here's how I finally got it going.

Step 1: get the first unit working as yer basic, bog-standard wired router. The provided documentation is OK here but one thing to note is that it will, on start-up, want to look for firmware updates. This was OK for me because I was swapping out a known, working (Buffalo) unit that demonstrably had working Internet access so that process was able to complete OK before going into set-up mode. Mostly, you can leave a lot of stuff in there at the default setting for now and it should basically work, though I should say that I used manual set up and not the provided wizard because I've never had good luck with those things.

Step 2: once working wired, the next step is to make sure you can access the main router wirelessly. Set-up your preferred security options. (I use pretty weak options here because the neighbours are so far away that they won't be able to get any 5 Ghz signal at all, and anyway drive-by Internet theft isn't much of a risk at our house!) One thing to note: once in repeat mode WPS won't work, so don't go relying on it, OK??

Step 3: in wireless repeat mode, there are a bunch of restrictions which you will now need to take into account as we move forwards :
- You can't repeat 5 Ghz and 2.4 Ghz at the same time. Yes, you read that right. Despite buying a parallel, dual-band router, it turns out that the repeater will only extend one of them. I opted for 2.4 Ghz coverage (the most common band) to be extended.
- WPS doesn't work, but I didn't really care. Setting up wireless clients isn't that taxing after all, and if you think it is then you are probably going to have a hell of a time getting all this stuff to work anyway :-)
- Auto channel selection is a no-no on the band you will be repeating, so just pick one. I noticed previously that in auto-channel mode the router set-up channel 1 so I just used that as the manual selection.
- You will have to restrict maximum link rate. I use 130 Mb on the 2.4 Ghz channel and that worked for me.
- The repeater needs a fixed IP address so you'll need to limit the DHCP range that the base station will grant addresses from in order to clear some head room. I set an upper limit of 240, leaving, for example, 250 available as a static address for the repeater.
- Enter the MAC address of the repeater into the appropriate place on the designated tab (named, cunningly, "Wireless Repeating Function").
Having done all the above, make sure that everything is still working. And by that I mean "turn it off and on again so you really know it works", OK? If so, shut that unit down and plug-in the other one, i.e. the unit that will become the repeater, and connect it up to the Internet and LAN.

Step 4: Kick-off by getting this device up and running as a wired router, as per step 1 above. The reasons for this are to make sure you have both units at the same firmware revision level and that it's working properly overall. Use the same basic settings (e.g. SSID, pass-key and channel one operation on 2.4 Ghz) entered into the base station.

Step 5: OK, so now we'll add the settings that this device, as a repeater, will work from. The tricky thing here is that each change, made on each separate tab on the administration menu, requires you to hit "apply" before moving on. Alas, that means that some of those changes render the device invisible, especially if you are trying to set it up from a wireless connection! (I wasted a lot of time trying to figure out how to work round that one ...) Therefore, save setting up the Wireless Repeating Function tab for last. (However, if memory serves me then there's one other step that causes problems and that's setting manually your static IP address, 10.0.0.250 in my case. You'll need to enter that directly into the browser you are using for configuration once the setting is applied in order to continue configuring the device.) So in summary, you will a) assign a static IP address to the repeater, b) enter in the MAC address of the base station, i.e. the one that's currently sitting on the floor not connected to anything, right?) and c) tick the box to make this a repeater.

Step 6: Put back the first router in place of the wireless repeater you just configured. All being well, it should be working for both direct wired and wireless connections, exactly as you left it.

Step 7: turn on the repeater while monitoring the configuration of the main router. You should be able to see from the status information that the repeater is seen on the network (look at attached devices for the 10.0.0.250 address).

Step 8: go to your static IP address (i.e. http://10.0.0.250/) and log-in to the repeater. The configuration menus should now show some items as greyed-out and the status information should show that it's operating happily. One thing to note, in my set-up I was getting a reported link speed of only 11 Mbits! Your mileage may vary but it's worth noting that the link quality was reported as "fair" so the radio signal wasn't that bad.

OK, you should now be up-and-running. However, I have to say that this network topology is a bit of a compromise to say the least. I now find that wireless devices, because they like the strongest signal, will attach to the repeater when in fact I want them to be on the base router for maximum throughput on the internal network. At some point, I'll try giving the repeater a separate SSID to see if I can control which devices lock-onto the repeater and which go direct to the base router. After all, a "good" signal at 130 Mb is way better than an "excellent" signal offering all of 11 Mbits! Still, on the plus side then my Internet radio in the garage now gets a signal and we can move around PCs more freely now that there's coverage everywhere.

Postscript:

Robert, a reader of the blog, contacted me to see if I had any additional advice as he was still having some issues getting this to work, albeit with the 3300 model.  The exchange, and additional input from Netgear, follows below ...
----------
Hi. Thank you so much for your post about setting up your WNDR3700. It’s way better than anything else I’ve found. Unfortunately, it’s not working for me. Would you mind answering some questions? If not, feel free to say no. But if so:

The symptom is that when I turn on the repeater, devices that were connecting to the router refuse to connect wirelessly at all. They report that they can’t get an IP address. I may be missing a few pieces of info:
What do you have set as your Gateway IP address? I set mine as my main router’s IP address as of that moment, but that’s dynamically assigned by my ISP. Also, my router shows its IP address as 192.168.1.1, but in reality it’s something like 76.14.67.xxx

What did you set as your DNS server(s)?

On the Wireless Repeating Function screen, what did you set as the repeater IP address?

One more detail: As you suggested, I was going to turn off DHCP on the repeater as my last step, but as soon as I enabled the repeating function the LAN setup link was greyed out. I assume that turned off the DHCP function but maybe not. Do you know?
----------
Hi Robert,
 
I am happy to answer questions but should begin by saying that, after just a couple of months running that configuration, I did indeed throw in the towel and ran a cable under the house. The throughput issue and lack of dual band repeating made working that way enough of a pain that drilling holes in the walls and through floor joists didn't see so unattractive all of a sudden! 

Therefore, I can't look at my present settings but instead have to rely on memory ... oh dear!

I don't think I changed the main router's gateway address, leaving it to be assigned by my ISP and set however it was when just the main router was connected on its own and working. Just to be clear, under "Basic Settings" I have Internet IP Address set to come from the ISP, as is the DNS address, and don't set those myself (though I have tried the Google open DNS settings in the past to see if lookup were any quicker, which it wasn't). I don't think it matters what shows up in the greyed-out boxes alongside what you see were you to set things manually; i.e. I don't think it's saying that those are the addresses your ISP has assigned.
 
However, under "LAN Setup" I then have it set to use IP addresses on my house network starting with 10.0.0.1 onwards and have the "use router as DHCP server" box checked. Alongside that, I restrict the range of IP addresses it can issue to 10.0.0.2 to 10.0.0.199. That leaves a small group of addresses, 10.0.0.200 onwards, that are unallocated and I used one of those as the fixed IP addess of the repeater. That should ensure you don't end up with the possibility of duplicate IP addresses being issued and it also means that you can then directly ping the repeater to see what's going on because you always know its fixed IP address (I used 10.0.0.250, for example).
 
The other thing to try that might help illuminate what's happening is to give the repeater a different SSID. That might make untangling who connects to what a bit easier, as least temporarily until things start behaving.
 
Hope this helps?
----------
After getting Netgear support to kick me up to phone support I got the repeater working. First, here are the instructions they sent:

The UI doesn’t match that of the WNDR3700, but it was close enough. The instructions say I can run at up to 270MBPS with WEP, but you can’t do that on the 3700 at least. I’m running it at 54MBPS with WEP, which is faster than what I can actually get. They also only briefly mention that you need to configure a static IP address on the repeater that’s outside the DHCP range of the base station. The key bit of information here is that the channel needs to be the same on both devices. I tried channel 1 at first and that didn’t work. I then tried channel 11 and that worked.

Also, the technician I spoke with said that I can repeat both the 2.4 and 5GHZ bands, but that the range of the 5GHZ band is so low that there’s no point. So I’m just repeating the 2.4 GHZ band. I now have a strong signal and 9 MBPS download speed in rooms that had had no signal before.

2 comments:

Iain said...

Funny....i just upgraded the home network as well....2.4Ghz/5Ghz. We have gone mac, so we used a time capsule (background backup kit) and they have an airport express kit as a repeater. Expected 3-4hrs of hard toil, but in the end, about 30 mins. Apple really have the sysadmin thing down to an art.

Harmanpreet Singh said...

Thanks For sharing this article....

netgear support