IP address and ip mask

[gmgbg]

Hi, if you enter address 192.168.xxx.xxx to a IP Office and ip mask 255.255.192.0 you get a warning, this is not a valid ip mask, should be 255.255.255.0.
I know this is not a normal ip mask for that ip address but is should be allowed to do.
There is a couple of strange issues if I enter this.
Is there anyone that knows the reason for this.

Thanks

 

[amriddle01]

It basically does not like invalid subnet masks, that address is a class C so should be 255.255.255.0 as the system suggests, I know it doesn't really matter and it is annonyoing.

ACS - IP Office Implement

"I'm just off to Hartlepool to buy some exploding trousers

 

[kholladay]

IP Office doesn't like it when you ignore the standards of classful addressing, perhaps they should have abandoned them back in the mid '90s like most others. Using an 18-bit mask on a 192.x.x.x network looks like a supernet to the system in that the 192 class is setup for 24-bit to 30-bit masks. They prefer that you stick to the mask that "should be" associated with the IP address you selected. You'd get the same error if you tried to use a 172.16.0.0 with a mask of 255.252.0.0 instead of 255.255.0.0.

Kyle Holladay
ACA-I, ACA Call Center, ACS-I, ACS-M, TIA-CTP, MCP/MCTS Exchange 2007
ACE Implement: IP Office

"Thinking is the hardest work there is, which is the probable reason why so few engage in it." - Henry Ford