I presume you mean a 255.255.255.252 mask, right ?
One simply way of working out the number of useable addresses you can have in this case is to subtract the last octet from 256 and then take a further 2 away from it. You have to subtract 2 from this to account for the network and broadcast addresses, respectively.
255.255.255.252: 256-252-2 = 2
255.255.255.248: 256-248-2 = 6
This only works if the first three octets are 255. However, this can be extended to cases where the mask is less than /24 too.
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.