[mythtv-users] Multiple boxes on different networks

[Jawaad Ahmad]

Here is some FYI for anyone Googling error messages...

Since I changed the IP addresses to point to the next-level port-forwarded
router, I have seen a message similar to the following every night on
mythbackend, followed by the mythbackend stopping:

--- BEGIN mythbackend.log ---
2006-11-06 22:00:51.250 Event socket closed. No connection to the backend.
[mpeg2video @ 0xb72a1188]invalid cbp at 4 4
[mpeg2video @ 0xb72a1188]Warning MVs not available
2006-11-06 22:16:10.580 Connecting to backend server: 192.168.1.3:6543 (try
1 of
 5)
2006-11-06 22:16:10.586 Connection timed out.
                        You probably should modify the Master Server
                        settings in the setup program and set the
                        proper IP address.
--- END mythbackend.log---

I guess that takes care of that, Lucas. Yesterday, I simply restarted
mythbackend; however, today, I specified the IP address in mythtv-setup as
the original 192.168.0.x, and pointed it towards itself using the original
192.168.0.x address; then I restarted mythbackend. This didn't happen before
I changed these two IP addresses to 192.168.1.3. Let's see if it stays up.
(Good thing Smallville wasn't on!)


Lucas,

> If you are runing routed(8) (or some other routing daemon) on all hosts,
then
> you probably won't need to modify anything, as long as the subnets are set
up
> correctly. A quick check with netstat -r will tell you if something is
amiss.

I'm not familiar with routed. I'll research it before I do anything else in
order to digest your post. I know it's not running; I just did a ps on both
hosts and got nothing (...well, except of course the grep).

> on the internal gateway (192.168.0.1/192.168.1.3) make sure there is no
NAT (I
> can understand your need for NAT on the border gateway 192.168.1.1).

Can this be done simply via configuration, or would I physically move my
router around for this?

> sysctl net.ipv4.ip_forward=1

I'm guessing this would stay in-effect until the next reboot. I'll have to
figure out how to make it persist, if necessary.

> if you post the copy of the netstat -r for the following hosts, we can get
a > > good look at what is actually happening:
> 
> 192.168.1.3
> 192.168.1.2
> 192.168.0.2
> 
> and the output of
> 
> sysctl net.ipv4.ip_forward
> 
> on the internal gateway.

Alright! I confess!! There is no host with IP address 192.168.0.2; I lied to
try to keep things simple. The true IP address is 192.168.0.76, subnet mask
255.255.255.192, with gateway 192.168.0.65. I had this set up from a prior
exercise and have left it alone, but the rest of it is as I stated.

Here is the real conceptual diagram:

            [ ] 192.168.1.1/24
             |
    +--------+---------+
    |                  |  192.168.1.3/24
   [ ] 192.168.1.2/24 [ ] 192.168.0.65/26
                       |
              +--------+---------+
              |                  |
             [ ]                [ ] 192.168.0.76/26

So take your pick - the simple setup with the 24 netmask, or the complex
setup with the 26 netmask. I apologize for any confusion.

The tables I provided below have been copied unaltered.

[user at 192.168.1.2]$ netstat -r
Kernel IP routing table
Destination     Gateway         Genmask         Flags   MSS Window  irtt
Iface
192.168.1.0     *               255.255.255.0   U         0 0          0
eth0
default         192.168.1.1     0.0.0.0         UG        0 0          0
eth0

[user at 192.168.0.76]$ netstat -r
Kernel IP routing table
Destination     Gateway         Genmask         Flags   MSS Window  irtt
Iface
192.168.0.64    *               255.255.255.192 U         0 0          0
eth0
default         192.168.0.1     0.0.0.0         UG        0 0          0
eth0

[user at 192.168.1.3]$ netstat -r
(From the router's Web interface...)

Routing Table Entry List

Destination LAN IP  Default Gateway  Subnet Mask      Interface
192.168.0.64        0.0.0.0          255.255.255.192  LAN
192.168.1.0         0.0.0.0          255.255.255.0    WAN(Internet)
239.0.0.0           0.0.0.0          255.0.0.0        LAN
0.0.0.0             192.168.1.1      0.0.0.0          WAN(Internet)

[user at internal_gateway]$ sysctl net.ipv4.ip_forward

If this is my poor li'l Linksys WRTP54G, I have no idea how to get/set this
information...unless someone's figured out how to ssh into it by now. ;)

Sorry I can't provide more info!

> if the internal gateway is not a computer, you could just set it up in
bridged
> mode, and have everything on the same subnet (much easier)

I'll research this and see if I can set it to bridged mode. If I remember
correctly, this goes by another name, correct?

Thanks for the help!