Odd Glitch on 2700 - Anyone any ideas ?

[JB]

I have just had a strange glitch on my 2700 and wondered if anyone else has had this?

We just realised that none of the browsers in the house could connects out to distant web sites. Everything else on the internet connection was fine. (SSH, Email, News, VOIP). All the browsers are hardwired to the 2700 and they all acted the same with a response from the 2700 stating that it could not connect to the remote sites. I can't remember the exact text but it wasn't a timeout message. Carrying out a reboot of the 2700 didn't resolve the issue.

At first I put it down to an internet glitch but after an hour decided to try a different router (Linksys) which worked perfectly.

So I've now carried out a factory reset of the 2700 and re-input all the details. It is working fine now but I'm curious as to what went wrong. The unit was manufactured in 2008 and six months ago I flashed it (down) to v5.29.107.12 firmware to prevent the dreaded v6 OTA upgrade.

Has this happened to anyone else or anyone got any ideas?

[Rik]

Did you check to see if it was picking up DNS correctly, JB?

[JB]

Good point Rik. As far as I can tell it was.

As it is the weekend family were waiting to use the internet so I didn't have much time to analyse the effect. If it happens again I'll ensure DNS is one of the checks I make.

Edit: Thinking about it, other protocols which use DNS were working, just not http (port 80).

[Rik]

Odd. I wonder if the router was blocking the port for some reason?

[JB]

That's what it looked like Rik. If it happens again I'll check and reset DNS and Firewall settings.

I vaguely think this may have happened before but I had attributed it to an internet glitch and I think I recall it cleared on it's own.

[Rik]

Maybe the router just wanted a break?

[JB]

Found the answer. It was in the firewall advanced configuration. I had the "Excessive Session Detection" ticked, which is the default. At the time I was using uTorrent to download two major distros from multiple seeds. I guess the 2700 saw this as some form of attack although quite why it screwed up port 80 I am not sure.

Unticking the box brought a resolution and it has been fine for days now.

[Rik]

Thanks for that, JB.