Is there mask for class D ip address? As it is for multicast, I am not sure about it. I read somewhere that D ip addressas are 32-bit network addresses and they dont have hostID, but in the following link I read that the number of bits for network and host is undefined in the class D. I am a little confuse a bout it, would you please guide me?
First classful addressing isn't used anymore, it's classless now.
Class D like any other Classes, all IPv4 addresses , are 32-bit.
Now, Judging by this link.. http://www.tcpipguide.com/free/t_IPMulticastAddressing.htm
it doesn't have network and host bits. If it's a multi-cast address then one IP would go to multiple machines anyway 'cos they'd all have that IP.
That tcpipguide link about Class D addresses has a table with more than the table on the wikipedia page on classful addressing.
I suppose in this case not defined means no network fields and host bit fields which is what you say you read, which makes sense and I think that's what the wikipedia page really meant when it said undefined. There are also going to be some addresses that IANA never assigned..but no doubt some multi-cast addresses were given out.
I don't know if you'd call the whole thing a network address. Network address is normally an address ending in .0 representing the subnet. I don't think a multi-cast address is referred to as a network address.
A netmask is used to divide an IP address into a network part and a host part. Multicast addresses don't have network parts and host parts, so it is meaningless to talk about a netmask.
A multicast address is just a 32-bit address within a well-known range that hosts subscribe to using a protocol such as IGMP.
Class D IP addresses have the first four bits set to 1110, the rest of the bits are available. So the range for class D addresses is from 126.96.36.199 to 188.8.131.52.
And the netmask will be 11110000.00000000.00000000.00000000 in binary and 240.0.0.0 in decimal.