[mythtv-users] Pixelation/Bad Recordings HDHR Prime -- I am at my wits end

[Greg Woods]

On Wed, 2013-08-28 at 12:09 -0700, Gary Buhrmaster wrote:

> With rare exceptions, the "management" address for all cable modems
> is 192.168.100.1 

Certainly not so any more. I just got a new modem from Comcast, a DOCSIS
3 to replace the old DOCSIS 2. This modem is clearly designed as a "one
size fits all" for all of their customers. It has jacks for the phone
service. It has a wireless access point built in and four ethernet
ports. It is hard-coded with an IP address of 10.0.0.1, and it insists
on assigning 10.0.0/24 addresses to every machine in the house. The old
dumb modem was really just a bridge; whatever machine you plugged in to
the ethernet port got the public IP.

For me, this change sucked, because I have IP addresses hard-coded in
all sorts of places (including MythTV of course). So I basically had to
reprogram my Linux system that was acting as my router to account for
this; it is attached to the "house" network, so that all the other
machines in the house can keep their IPs. And then it is attached to the
10.0.0/24 net and sets its default route to 10.0.0.1. Thus I have
another router between me and my public IP. I had to make a number of
other changes to make this work (IPSEC tunnels and so forth; fortunately
the Comcast box at least supports port forwarding). I continue to use my
Netgear router as the wireless base station (that's all the Netgear is
now, but it can be put into place to replace the Linux router if there
should be problems with that box). The Comcast wireless network is
useful as a "guest" network, so that I can give guests access to the
Internet without giving them access to the house net.

Comcast is in the process of replacing all of the modems in our area
with these new ones.


> After the modem downloads its config from the MSO it also gets a
> management IP address (in theory only available from the cable side)
> which is used to configure and poll the device for management purposes

There is no way to access this through the web interface. All I can see
is the "public" IP and the 10.0.0.1 internal one. But it wouldn't
surprise me if the external interface has an additional address. One
more reason to have another router between the Comcast device and my
other systems. I certainly don't trust them. Or the teenage hackers in
the neighborhood; how long before this "management" network is used to
break into somebody's house machines? 

--Greg