Camera Subnet

[nothappy]

Sweet, I found this site...someone actually found the serial port....

Poking the Swann NVR-7400 – The Rantings and Ravings of a Madman

poking around I can actually change the subnet of the Cams but it doesn't look like the cameras are getting their IP from the NVR, must be hard coded on the camera? I don't see a dhcp daemon running in the process list.

And I was able to change the subnet that the NVR gets to a 172.16.0.x/255.255.255.0 and it's able to route packets as long as the PC IP address is in the 172.16.0.x pool. If I try to ping the NVR from 172.16.3.x/16, it doesn't work.

 

[Hammerhead786]

<Snip>….

If I try to ping the NVR from 172.16.3.x/16, it doesn't work.

That is exactly how it should be because it is on a different subnet. You are using a 24 bit subnet mask (255.255.255.0) on the pc network which is /24 and not /32 as you keep referring to. /16 is a 16 bit subnet mask (255.255.0.0).

For a /16 network you can have 2^16 network addresses and 2^16 -2 host addresses. Of these the address ranges 172.16.0.0. to 172.31.255.255 are in the private ip address space.

For a /32 network you can have 2^24 network addresses and 2^8 -2 host addresses.

 

[nothappy]

That is exactly how it should be because it is on a different subnet. You are using a 24 bit subnet mask (255.255.255.0) on the pc network which is /24 and not /32 as you keep referring to. /16 is a 16 bit subnet mask (255.255.0.0).

For a /16 network you can have 2^16 network addresses and 2^16 -2 host addresses. Of these the address ranges 172.16.0.0. to 172.31.255.255 are in the private ip address space.

For a /32 network you can have 2^24 network addresses and 2^8 -2 host addresses.

Crap, your right, replace every where I say 32 with 24.....can't multiple 8x3.....had 255.255.255.0 notation right

 

[Hammerhead786]

Crap, your right, replace every where I say 32 with 24.....can't multiple 8x3

Just for the record, I'm not trying to be an a$$ about this ^^. Are you not able to manually assign the cameras with an ip address as per the user manual?

 

[nothappy]

I must have missed that in the manual, let me go look.

There is nothing in the manual that says you can change the IP address of the cameras.

 

[Hammerhead786]

Apologies, I misread the manual.

 

[nothappy]

Just when I think I got it figured out, Swann has just got to make it difficult....there is no config file I can find anywhere on the file system. They have one executable that does everything called "dvr". Once you start it, it whacks all interfaces and reconfigures it with a hardcoded 172.16.25.x. That's the dumbest thing I've heard of. When we did it, we used the Linux resources and init scripts to configure everything. Hell, at least put it in a config file not hard coded in an executable....that's just stupid.

 

[Hammerhead786]

Just when I think I got it figured out, Swann has just got to make it difficult....there is no config file I can find anywhere on the file system. They have one executable that does everything called "dvr". Once you start it, it whacks all interfaces and reconfigures it with a hardcoded 172.16.25.x. That's the dumbest thing I've heard of. When we did it, we used the Linux resources and init scripts to configure everything. Hell, at least put it in a config file not hard coded in an executable....that's just stupid.

This is one of the reasons I try to avoid proprietary crap.

 

[nothappy]

Well, I think I got a work around. The cameras are actually on a /16 subnet, which exactly matched my network. if I reconfigure the camera network as a 172.16.25.x/24 everything works, and it doesn't seem to mess up the dvr executable listening on all the ports.

# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         172.16.0.1      0.0.0.0         UG    0      0        0 eth0
172.16.0.0      0.0.0.0         255.255.0.0     U     0      0        0 eth0
172.16.25.0     0.0.0.0         255.255.255.0   U     0      0        0 eth1

Given their stupid executable that whacks everything, I need to figure out how to run the ifconfig command after dvr is started. Unfortunately their file system is cramfs, so I'll have to extract it, modify it, and reflash it......what a pain this has been.

Nice forum, best response time I've seen....thanks again!