Error in ip configuring

[krahulbgp]

Why i am getting bad mask error can anyone explain ? 

[Kasun Bandara]

@krahulbgp 

hi, this for subnet 255.255.255.252 you can have total 4 IP addresses with 2 usable IPs. for the IP you entered, network range is 201.0.0.0/30. so your 4 IPs will be 201.0.0.0, 201.0.0.1, 201.0.0.2 and 201.0.0.3. each network have 2 IPs for network and broadcast addresses.

201.0.0.0 - network address

201.0.0.3 - broad cast address

so you cannot use 201.0.0.3 for interface. you need to use 201.0.0.1 or 201.0.0.2

[Joseph W. Doherty]

Possibly the error message is misleading.  The IP address and network mask COMBINATION is invalid.  You need to change the IP address (as it's the broadcast address for an /30, as explained in @Kasun Bandara's reply) or the network mask (or both).

BTW that IP address would be valid in a /32, /31, /29, /28, . . .  Just not the /30.