Address range question

[mparry]

Hi,

I have a network which uses the following address range:

192.1.1.X

We only have a small network of about 50 nodes. I have servers on 192.1.1.2/6/8/16 etc. I am about to setup a firewall which will perform a NAT function. Is there any reason why I can't keep using my current address range - instead of changing to a qualified private address such as:
192.168.0.X

In the future I may setup terminal servers which may need to reside on their own subnets - is this a reason to change to a better address range?

Thanks for any help.

Marcus

 

[jimbopalmer]

If you never need to get to the internet, no. Those sites on the internet which REALLY own the addresses in 192.1.1.x will be inaccessable to your network, since your router will assume they are internal addresses, not internet addresses. I tried to remain child-like, all I acheived was childish.

 

[Morsing]

You can't do that!! One thing is that it's not allowed (*really*) but your router will get very confused.

If you've told your router about the internal network range correctly, you'll never be able to access those computers out there in that range.

If you haven't, then it simple won't work + you're in deep trouble because someone will be pissed off.

Change your addresses!!

Cheers Henrik Morsing
Certified AIX 4.3 Systems Administration
& p690 Technical Support

 

[mparry]

cheers... I'll change it.

 

[nohair]

Hi,
Really, you should have your addresses in RFC1918 format (eg 192.168.0.0) as these are the reserved private use. In reality, however, you can use whatever you want. You will be in a world of pain should you try to inject these routes into BGP as your private range, 192.1.1.x is allocated to Bolt Beranek and Newman Inc. (source:

http://www.arin.net

do a whois search, you'll find own is assigned what). Though your ISP will be smart enough to drop route updates from you should you try to advertise them...which is unlikely as ISP don't like to peer your routers with their, they like to do the advertising themselves (they're the experts).
As long as you configure NAT properly it doesn't matter what you have inside, but as mentioned above, if you use allocated ranges inside it will impact what you can reach on the outside...hence the reason you should use the addresses defined in 1918.

BR,
-Stephen

 

[mparry]

Hi

I've just been told that a company we have a WAN connection to is using the the private network address space 192.168.1.0/24 and I've been asked to choose another address. Is (for example) 192.168.6.x a viable private addeess to use?

Thanks

 

[jimbopalmer]

Yes all of 192.168.x.x is available, you may wish to agree to ave one company be below 192.168.127.x and the other above 192.168.128.x so you never conflict as you grow I tried to remain child-like, all I acheived was childish.

 

[mparry]

Thank you.