MAC address cloning with router or not?

SuperCow · 12-07-2005, 18:19

Hello everyone

I recently purchased a Linksys router (BEFSR41 v3) to link up 3 PCs in my house. Since I had previously been using NTL's internet connection directly with a PC network card I have been assuming that I would need to clone the NIC's MAC address on the router to keep my internet connection. However I didn't need to and the Internet connection worked straight away with the router, which I don't quite understand. I didn't re-register or anything, and I thought NTL required the MAC address used during the registration process to obtain Internet?
Obviously this shouldn't be a problem as such, but I've been having disconnection problems with this router (once a day on average) that are only resolved by resetting the router, and I've been reading on the net that the MAC address used by the router could be a factor in this problem (i.e. I am wondering whether I should clone the original NIC's MAC address after all).
Any idea?

Raistlin · 12-07-2005, 18:20

Are you using a Stand Alone Cable Modem (SACM) or a Set Top Box (STB. Also used to provide the TV services)?

SuperCow · 12-07-2005, 18:56

I am using a stand-alone cable modem provided by NTL (Terayon).

Paul K · 12-07-2005, 19:14

Did you follow the standard routine of
power everything off,
connect SACM to Router and router to SACM,
power on SACM,
wait till lights lock,
power on router,
wait till lights settle,
power on PC,
open browser.
Also are you running default settings on the router?

nibbles · 12-07-2005, 19:17

maybe ur routers firewall is blocking dhcp requests?

Raistlin · 12-07-2005, 19:27

Quote:

Originally Posted by nibbles

maybe ur routers firewall is blocking dhcp requests?

Good thought, I had the same idea myself. Not sure why rebooting the router would cause that though.....

If you can, it would be worth testing the router with another machine just to rule it out as the cause.

Are you running a software firewall (such as ZoneAlarm, Sygate, the XP firewall) by any chance?

eerrrr · 12-07-2005, 20:08

Have you tried upgrading the router's firmware?

This may not be the case, but if your router's second hand then it might be on its way out, or it may just be faulty anyway. Linksys' BEF series are known for their crashing and dying I'm afraid. I've already been through 2 (each lasted a year) and my third one's going as well.

I recommend doing some reading here:
http://www.dslreports.com/forum/linksys

SuperCow · 12-07-2005, 20:40

>Also are you running default settings on the router?
>Have you tried upgrading the router's firmware?
Yes. Tried static IP or DHCP, no changes. I also upgraded the firmware to 1.05, then back down to 1.04.17, same problem (I'm now back on the most recent version 1.05). I am not using any software firewall. My BEFSR41 v3 router is also brand new (bought it from Dabs a few weeks ago).

Just so that it's clear, the router works most of the time, it's just that sometimes, roughly once a day, the connection will drop and I won't even be able to connect to the router itself (using the 192.168.1.1 address). Pressing the router's reset button briefly will put everything back to normal.

So you guys don't think the MAC address cloning could be an issue here? Is it expected that NTL's internet connection would "just work" without cloning the MAC of the NIC that was used for registration?

Raistlin · 12-07-2005, 20:45

Mine "just works" without any problems at all.

The only time my router or modem get rebooted is if I have a power cut or if I'm doing any moving about or anything.

FYI both my machines have static IP addresses (one laptop and one desktop), so the DHCP server on the router is switched off.

There shouldn't be any need to clone the MAC address of the NIC to the router, the SACM will reprovision itself to whatever device it is attached to if it is rebooted.

The fact that it's dropping once a day makes me think that it's a firewall issue (since you aren't running a software firewall it's most likely the internal firewall of the router). I had exactly the same problems when I was running ZoneAlarm before I got the router.

TBH, other than suggesting you try the router on another machine (or, better still try a completely different router) I can't think of anything else that you can try.

My inclination is that it's something either not set up correctly, or not working correctly, within the router. What it might be though I have no idea.

Does your router keep any logs at all? If there are any error logs or firewall logs that may throw some light on what is causing your problem.

12-07-2005, 20:46

Quote:

Originally Posted by SuperCow

So you guys don't think the MAC address cloning could be an issue here? Is it expected that NTL's internet connection would "just work" without cloning the MAC of the NIC that was used for registration?

On a SACM, providing you power the modem off before connecting a device with a different MAC - shouldn't be an issue. AFAIK, it is only STBs (Set Top Boxes) which require new MAC addresses to be registered.

Raistlin · 12-07-2005, 20:48

Actually, and I'll need one of the NTL bod's to help me out here, would the NTL modem error logs throw any light on this at all?

SuperCow · 12-07-2005, 20:51

>Does your router keep any logs at all?
The only logs available are the incoming and outcoming traffic; I will keep any eye on those though.

Raistlin · 12-07-2005, 21:00

Ok.

You need to look for wany requests that your router is blocking, it could be that the modem is trying to communicate with the router (or vice versa) and that the communication is being blocked for some reason.