-ray <[EMAIL PROTECTED]> writes:

> And you see tons of netbios broadcasts.  At least i did on Cox cable modem 
> in Hammond.  I always wondered though, is this bridging done at the cable 
> modem itself, or further upstream at the headend?  Seems to me based on 
> the physical layout of the coax network, it'd be hard (impossible?) to 
> bridge upstream.  I never did figure out how to change the modem firmware 

If you're in Hammond you have a modem from Charter.  I'm assuming
we're talking DOCSIS and not the com21 stuff that was discontinued.
That was part of the network I built and managed until 10/02.  The
bridging is done inside the modem and not at the headend.

Firmware upgrades are 'pushed' from the provider.  You can either
put a setting in the DOCSIS config file telling the modem the name of
the version it needs to download and the tftp server IP to get it from
(usually the same as the one it got the DOCSIS file from) or you can
use SNMP to 'tell' a modem this information.  The latter method
is how you might do it locally.

> and/or connect a device outside the modem to see what traffic was really 
> coming down the line into my house.

You'd have to build an interesting device indeed to do that.  At the
CMTS itself, I could attach to an ethernet port and put it into a
monitoring mode and capture the DOCSIS frame activity which I could
then decode with ethereal on my Linux laptop (keeping it topical,
y'all)

-- 
Scott Harney<[EMAIL PROTECTED]>
"...and one script to rule them all."

Reply via email to