NAT

[aksher]

Can we use a statement like this

nat(inside) 1 10.20.2.2 255.255.255.251 ??

[m.sir]

255.255.255.251 is invalid mask

you must use 255.255.255.252 or 255.255.255.248

When using binary notation of IP mask you need all on ONEs from left... If we look to last octet you can have following masks

128 its binary 10000000

192 its binary 11000000

224 its binary 11100000

240 its binary 11110000

248 its binary 11111000

252 its binary 11111100

M.

hope that helps rate if it does

[aksher]

But for a wildcard mask we can specify any range know for ex in ACL on firewall

access-list 100 permit ip 10.1.1.1 255.255.255.251

here the range can be from 10.1.1.1 to 10.1.1.5 know?

[m.sir]

You CAN NOT use mask 251 its not possible

valid mask is 248 or 252

if you want host 10.1.1.1 to 10.1.1.5

its 10.1.1.0 255.255.255.248

M.