Name Server?

[Мастер]

So in my new place, there is "free" internet, and they even left me a wireless router.

I also have my own wireless router, which in the old place was hooked up to the "complimentary" internet service which came with the cable television. This set up has been replicated at the new place.

At the moment (I'm probably going to change this), I therefore have wireless internet service provided from one side of the living room, and also from the other side.

A strange phenomenon may be observed today. Certain web sites (e.g., an astronomy board someone posted a link to from this board) are completely inaccessible through the one wireless router, but no problem through the other. Other web sites (e.g., this one) are no problem through either wireless router.

What would cause this sort of behaviour? I am thinking maybe it is a name server issue, but could there be other explanations?

[Lance]

Well, you can test it by setting the name servers on your PC itself. You could use Google DNS, 8.8.8.8 and 8.8.4.4

If everything works on both routers then you've proved the DNS theory. If not, then the ISP may have some filtering in place.

[Мастер]

Modified the approach slightly, and just did a ping to cosmoquest.org.

The ping failed, through either route, but it did tell me what IP address it was pinging. So I put that IP address into a browser window. Works through the one router, not through the other. So name service appears not to be the issue.

[Lance]

So it must be filtered somewhere is all I can think of.

[Мастер]

OK, I'm having all kinds of problems here, and it works both ways - on each router, there are sites I can't reach that I can reach through the other.

I believe it is a local problem, for the following reason - the one wireless router, I can't access BAUT. But if I plug a network cable from the same computer into the back of the same router, all of a sudden it magically works no problem.

So I think it is some issue of using two wireless routers close together (in both time and space) using a similar address space.

One wireless router occupies 192.168.45.X, subnet 255.255.255.0, and the other is 192.168.2.X, subnet 255.255.255.0. So I don't think there should be any conflict.

And yet, it seems like there is.

[Lance]

Can you temporarily shut one down for testing?

[Мастер]

Can you temporarily shut one down for testing?

Did that, and problems generally persisted.

Tried various things to flush the name cache and the routing table on the computer.

[Lance]

It's odd that it works wired but not wirelessly on the same router. Perhaps a master reset on the router?

[Lianachan]

What make and model are the routers?

[Мастер]

What make and model are the routers?

One of them is a Linksys, and it worked (mostly) without difficulty at the other location, distributing the interent coming out of the same cable/television box as before.

Not sure what the other is, I can check when I get home late tonight.

[Lianachan]

Was just wondering, as I've seen that exact symptom (works wired, but not wireless) suddenly appear on a Cisco 527W that had previously been working perfectly happily. Fixed by upgrading the firmware.

[Мастер]

Was just wondering, as I've seen that exact symptom (works wired, but not wireless) suddenly appear on a Cisco 527W that had previously been working perfectly happily. Fixed by upgrading the firmware.

Huh. I think Linksys is owned by Cisco.

I should have a look. However, I most likely do not have access to the administration of the other router. (I don't own it, the landlord owns it.) The Linksys one, I can control, provided I reset it (the administrative password I recorded, doesn't seem to work :()

[Lianachan]

Linksys are essentially Cisco's cheap and cheerful brand intended mainly for the domestic market, aye. The kit is generally quite different from Cisco stuff though, so it may be a coincidence that you're seeing that same problem I saw.

[Мастер]

FWIW, I am now able to access sites which weren't working before through the wireless side of the Linksys, without having done anything that seems like it should have an effect.

[Lianachan]

Yes, that sounds like a Linksys.

[Lance]

Not that it matters but Cisco recently sold LinkSys to Belkin.

[Lianachan]

It matters even less, but I don't think that's happened yet. I think they just announced the intention to sell it to Belkin a couple of weeks ago.

[Мастер]

Hmm, it occurs to me, maybe this other problem I've been having is related.

Sometimes the wireless connectivity would stop working. Disconnecting and reconnecting (which took just a few seconds) would inevitably fix the problem. I assumed this was a result of a new computer/OS, because I did not have the problem with the previous computer/OS using the same router. But maybe it is router-related.

[Мастер]

I've had the Linksys wireless router working no problem for some time. This is connected to the cable television box, which includes internet for free.

The other wireless router, which seems to be connected to the in-house internet, had issues. In particular, it did not seem to allow access to anything with a similar IP address (never worked out which bit exactly was the cut off point).

The other day, the Linksys quit. Well, the router kept working perfectly, but it seemed to be connected to something which provided no internet service. So I could log into a configure the wireless router, and possibly also other machines on the local network if I liked, but that was it.

I suspect the reason is that the "free internet" that came with the cable television was limited-time offer which has now come to an end. Need to look into that.

So I was left with a less-than-fully-functional internet connection, through the wall jack. Then I got the bright idea - switch the wireless routers. The Linksys, now connected into the wall jack instead of the cable television box, provides full access to the internet and everything on it.

So I think probably there was some misconfiguration in the other wireless router, with the subnet mask set as being "too big" - so when accessing similar IP addresses, it mistakenly treated those addresses as on my side of the router, rather than out on the internet. Does that make sense?

I don't have the administrative login for this other wireless router. I tried the defaults I found at some web page, they didn't work. I doubt the owner of the router will give me the information. However, I probably can reset it to the factory defaults.

[Lance]

That is certainly possible but I don't know how probable.

[Мастер]

That is certainly possible but I don't know how probable.

I don't know that I have any way of ever finding out for sure, since I can't access the router settings :(

But, symptoms - multiple devices (Apple computers, Windows computers, iPhone) unable to access web sites and mail servers within a particular range of addresses through the one wireless router, no trouble accessing other sites. When using a different wireless router (physically located in the same room, but connected to the internet through a completely different service), some of those same machines (Apple computers, iPhone, never tested the Windows computer) would be able to access the sites they couldn't access through the other wireless router. When the half-working wireless router is replaced by the fully working wireless router, everything fine. So same devices accessing the internet through the same connection, trouble accessing some sites with one wireless router, no trouble using another wireless router.

[Lance]

Yes, it sounds right, but for a private and public IP range to overlap shouldn't be able to happen.

I still think it could be filters.

[Мастер]

Yes, it sounds right, but for a private and public IP range to overlap shouldn't be able to happen.

I still think it could be filters.

Could it also be that maybe there was some static entry in the routing table that was incorrect, or that became obsolete at some point?

I don't know that I have any way ever really to tell for sure. Thinking about doing the factory reset thing on the other wireless router (the one that was giving the trouble) - any reason not to?

[Lance]

Not that I can think of. Go for it.