How can I fix the wireless connection problems with my BEFW11S4?
July 14, 2004 9:03 PM   Subscribe

Wireless Filter. I'm trying to make a Linksys BEFW11S4 v4's Internet light stop flashing so insanely. It's affecting internet speed in a big, big way. [MI]

So I'm at my girlfriend's, and her iBook's net connection is on the slow side. It's getting about 100kb/s down and 300kb/s up, according to net speed tests. I look at the linksys and the "internet" light is flashing constantly, even when the iBook's off.

So I connect the Book directly to the cable modem (ethernet), and after a modem restart, I'm seeing speeds of 2000kb/s down and 300 kb/s up. More like it.

So I'm guessing there's something up with the linksys. I've upgraded the firmware, and all the settings in the web config appear to be correct. I've googled a lot, but there's only unhelpful answers out there - "It's a virus!!!!" or "it's your cable company checking for serv3rs" - or one page that wants me to pay $9.99 to see an expert's answer.

I don't need none of that, hell, I've got a MeFi sign on. Anyone help?

(I'm sure that "expert" advice would amount to "ahem, good man, it may well be a virus, perhaps along the lines of Nimbda, forsooth. W00t!" anyway)
posted by bonaldi to Computers & Internet (17 answers total)
You know, not that this helps, but I was just thinking tonight about posting to AskMe about the same goddamn thing with *my* girlfriend's router. She's got a D-Link, herself, but it's doing the same thing... activity, lights, flashing non-stop.

My girlfriend recently purchased a brand new condo and was the first person to move into her neighborhood. It's one of those fancy-next-gen dwellings where everything is wired for web, but as it stands, the cable comes in, goes directly to the modem and wireless router, and none of the other room jacks are hooked up for ethernet yet.

When she first moved in, I thought it was odd because nobody lived around her, nor were there any other finished condos that any warchalking wi-fi junkie could be camping out in. The router claims a 150ft radius, but from the day she moved in and for about two months after, nobody lived near her.

She has a TiVo that is hooked up with a wireless adapter, but TiVo couldn't possibly be accessing the internet constantly 24-7 (literally).

Because I got a little paranoid, I set up MAC-address filtering, so currently, the only machines that should be able to access the router include her laptop, my laptop, and the tivo. But even after that, the damn modem and router are constantly flashing. I'm not talking intermittently... it looks like someone is downloading huge files constantly... extremely rapid flashing (no collisions) and without ceasing.

While I've never encountered speed problems like bonaldi, one very frequent problem is that our laptops (her win, my tibook) often will not recognize the signal. We'll then reset the modem, wait a sec, and everything will be fine again.

Is this activity just a fundamental characteristic of cable internet? I have DSL, myself, and unless I'm specifically making requests, my modem sits peacefully, lights never flinching. It's noticeable when someone is using my connection, whereas, it looks like someone is using hers every second of every day.
posted by Hankins at 10:04 PM on July 14, 2004

1. you have a mac, it is not a virus. Macs viruses have been demonstrated, but not found in the wild. And if they *were* released, there probably isn't enough macintosh density for them to propagate.

2. Your cable company can't get past the BEFW11S4 and into your network unless you have opened ports for them. It is theoretically possible to estimate how many computers are behind a NAT like the BEFW11S4, but (a) it is too much work for close to zero return and (b) it doesn't involve getting inside your network, so is irrelevant to your problem.

3. the BEFW11S4 devices support 802.11B, which is a frequency-hopping spread-spectrum technology. What that means is, when the unit gets interference it switches to a new channel and renegotiates the connection. It does this rapidly as a normal part of its operation, so when you get a *lot* of interference performance just degrades. Check to see if there are any 2.4 GHz cordless phones nearby. Big metal objects or blobs of water (people) also interfere. Check the signal strength on the mac (System Preferences, Network, Airport, I think).

4. Check for a firmware update at You don't actually need a PC to do the update - everything can be done through the BEFW11S4's micro-webserver (its address is
posted by Kwantsar at 10:16 PM on July 14, 2004

Cable modems *do* blink incessantly. Both my cable modem and my router are currently blinking away, with no real traffic coming to or from my computers. Cable is "shared" in a sense, as opposed to DSL in which you get your own connection all the way back to the telco. When cable was nothing but one-way delivery of content to the home, there was no reason to give each home its own connection, so every house in a neighborhood will generally share a single connection. If there is anyone else on the network in your neighborhood, you'll be seeing some of their packets.

So Hankins, I wouldn't worry. It seems normal.

Bonaldi, the blinking probably isn't a problem or a symptom of any problems. It sounds more like there's just something wrong with your wireless connection.
posted by whatnotever at 10:37 PM on July 14, 2004

My cable modem has a "data" light similar to the "internet" light on my router. Both blink more or less in unison, all the time. In fact, if they stop blinking (as they did last night for 15 minutes or so) I know I'm experiencing an outage.

So I say yes, this activity is just a fundamental characteristic of cable internet.
posted by hashashin at 10:51 PM on July 14, 2004

FWIW, the BEFW11S4 isn't a cable modem. The blinking light may just be indicating that the WiFi antenna is on and transmitting. It would be interesting to find out what it is actually doing.
posted by Kwantsar at 11:01 PM on July 14, 2004

Kwantsar, the blinking light on the router is probably the light indicating activity on the port to the cable modem. That's how it works on mine, anyway; the cable modem and the router blink in unison. The cable modem will ignore packets not intended for computers attached to it, I believe, but it still lets through lots of broadcasts that make it to the router.
posted by whatnotever at 11:05 PM on July 14, 2004

Like someone else said, maybe there's some 2.4ghz cordless phone activity. I bought a 900mhz phone just to keep that problem at bay.
posted by angry modem at 6:06 AM on July 15, 2004

I used to have that model before I went up to the 802.11g model. The lights used to flash a lot too but I didn't experience any slowdowns in throughput.

Try changing channels on the router. There might be some interference on that channel that causing the slowdown. I have 4 neighbors with networks and settled on channel 9 and saw a improvements.

Search Versiontracker for MacStumbler. It has a noise column when it shows the networks it stumbles upon.

You might want to check out this forum on broadband reports.

Or you could have a bad unit. My first Linksys was a lemon and I returned it to the store I bought it from and got a new one.
posted by birdherder at 6:22 AM on July 15, 2004

It's not limited to wifi. I have a linksys ethernet-only router hooked up to my cable modem, and it blinks ALL THE TIME. The wifi router connected behind it (netgear 802.11g) does not. I suppose I should test this by unplugging everything and seeing if it still does it.
posted by Caviar at 7:05 AM on July 15, 2004

There's no chance someone else is enjoying her 'net connection when the router is in the mix?
posted by yerfatma at 7:43 AM on July 15, 2004

(This is in addition to all the other excellent ideas so far): Try getting a wireless sniffer like Kismac or NetStumbler, turning off ALL other network applications on all your computers (this means closing Safari, iChat, NetNewsWire, etc, and heck, try turning off any machines other than the one you're sniffing with) and then looking at the network traffic with the sniffer. If you see a lot of crap scrolling by, it would be an indication of _something_ hogging your wireless bandwidth. If you do go this route, feel free to post a portion of the traffic here and I'm sure we can tell you what it means.
posted by cyrusdogstar at 7:55 AM on July 15, 2004

What "net speed tests" are you using?
posted by bshort at 8:27 AM on July 15, 2004

Step 1: Make sure no one else is sharing. (Turn on MAC filtering and/or encryption)

Step 2: Make sure your gear is good. Test the wireless with other laptops, test the laptop with other wireless. If either one shows slowness, replace the gear that seems to be the culprit.

Which internet light, specifically, is flashing incessantly? Is it "WAN", "LAN", "WAP" ...?
posted by SpecialK at 9:02 AM on July 15, 2004

Thanks for all the replies, everyone. I expected to get nothing, and instead I got great tips.

The light that's flashing is actually called "internet", and its flashing isn't always accompanied by flashing on the activity light of the cable modem. When I hook up directly to the cable modem, its activity lights pops on and off every now and then, but generally only when I'm sending traffic.

The "internet" light appears to be the cable-box link light. And the flashing is way too fast to be traffic (short of a torrent or similar), it's close to a blurring flicker. My current thought is that it might be a DHCP screwup or something.

(bshort: I used the test at )

It's definitely not related to actual computer traffic - I've locked it to only my MAC address, and the "wireless" light isn't flashing to show traffic other than my own at all.

I'm just about to try changing channels. I know the Airport card is OK because it worked in a hotspot on the other side of town last night.
posted by bonaldi at 11:09 AM on July 15, 2004

Bonaldi, that light means that your router is blocking, as it should, a whole bunch of portscans and other junk packets that would otherwise be hunting for something tasty at the end of your cable modem. It's unrelated to any speed issues you may be having with your wireless.
posted by SpecialK at 1:32 PM on July 15, 2004

Are you sure? It's going at a hell of a speed for that and there's no activity light activity on the cable modem at the same time and when there is it's not at anything like the same rate. Further, there's nothing in the router's logs to identify something like that happening, nor on the iBook's when I connect it directly to the cable modem

The massive speed drop also happens when I'm hooked to the router via ethernet, ruling out a wireless-only problem.

I'm beginning to think it's just a lemon.
posted by bonaldi at 1:45 PM on July 15, 2004

Actually, that light doesn't mean any of those things.

It means that there's a packet on the WAN interface that the router is 'interested' in. That's your inbound or outbound traffic, ARP's on the cable segment, and attack traffic aimed at your address... along with any other broadcast traffic on the segment, of which there is usual;y not much.

Mostly, it's ARP's from machines infected with Code Red, which scans the local subnet, generating ARP's for every address on it. Plug directly into the cablemodem and run a sniffer (such as Ethereal or tcpdump on Linux) and you'll see what's causing the flashes.

As for the speed problem, that might well be the router; Linky's suck.
posted by baylink at 5:12 PM on July 17, 2004

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