IP Addresses

[sleepytom]

I wonder if anyone has any thoughts on best practices when choosing IP addresses for AV equipment?

 

is it better to use class B or class C addresses? does it matter? why?

 

I'm able to get either class B or C working, both with and without a router, but I wondered if there was any theory to backup choosing one over the other?

 

Increasingly kit seems to default to class C 192.168.x.x type addresses but I presume this is to simplify setup with standard domestic routers rather than anything else.

 

I'd be interested to know what others have chosen to use and why.

 

cheers

tom

[bruce]

If connected directly to the global (routed) internet, you use the address range allocated by your service provider. Of course, that's relatively uncommon these days, unless you are one of the organisations that were allocated significant blocks of adddress space in the early internet days, so we generally use private address space and NAT.

 

Private address space is described in http://www.ietf.org/rfc/rfc1918.txt

Basically, 3 address blocks are available for private use, and are not globally routed.

 

These are:

 

10.0.0.0/8 10.0.0.0 - 10.255.255.255

172.16.0.0/12 172.16.0.0 - 172.31.255.255

192.168.0.0/16 192.168.0.0 - 192.168.255.255

 

As to which one you use - there's no technical reason to use one over the other, other than the size of the address space. The 192.168 addresses tend to be commonly used as defaults on domestic/consumer equipment, which is possibly a good argument to use another range.

 

The terms "class B" and "class C" are pretty much obsolete these days, but are still sometimes used to mean /16 and /24 netmasks respectively. In practice, you choose your netmask to suit the size of (number of devices on) your network.

[xllx]

The classful network model is a bit old school nowadays. It hasn't really existed since the mid 90's.

 

As long as you stick within the private address blocks mentioned above, you will be fine.

 

The only thing to consider is other companies/suppliers address schemes. I would suggest sticking clear of commonly chosen blocks, like 192.168.1.xxx just in case you end up on the same network as someone else using those addresses. Consider the address scheme used by other companies you regularly work with or sub hire off.

 

In an ideal world you would be on different networks or at least VLANs, but the last thing you want to do is find your projector address is the same as lighting's desk if you do find yourself on the same network.

[Wol]

10.0.0.0/8 10.0.0.0 - 10.255.255.255

172.16.0.0/12 172.16.0.0 - 172.31.255.255

192.168.0.0/16 192.168.0.0 - 192.168.255.255

 

/me looks at Art-Net

 

/me dies a little inside

[dbuckley]

I used to be really angry about Artistic Licence being clever enough to invent a half decent protocol, but not having the nouse to actually check if what they were doing was standards compliant. Internet standards, unlike those from some standards produicting bodies, are both free and readily available.

 

Perhaps this proves once again that common sense isn't actually common...