what is the difference between net ID and host ID??

Discussion in 'QnA (read only)' started by iinfi, Jul 17, 2005.

Thread Status:
Not open for further replies.
  1. iinfi

    iinfi mekalodu

    Joined:
    Oct 22, 2004
    Messages:
    1,534
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Navi Mumbai
    what is the difference between net ID and host ID??
    in a class C IP address say, 192.52.56.8 the first 3 octets denote the net ID while the last octet shows the host ID. what are the 2 used for ?

    again in a class B IP address say, 172.52.36.5 the first 2 octets show the net ID while the last 2 denote the host ID.... what is the significance of the netID and hostID???

    i got this definition for host ID frm google search, but i still didn't understand ...
    plz HELP ....
    thanks ....
     
  2. digen

    digen New Member

    Joined:
    Feb 8, 2004
    Messages:
    745
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Belgaum
    Its very simple mate.The network id is the id of the network & resembles the network.The host id is the identification of the host in the network.

    Class A:Network.Node.Node.Node
    Class B:Network.Network.Node.Node
    Class C:Network.Network.Network.Node

    The above is the way upon which its classified depending upon which Class the IP address belongs to.

    If there is a network with a number of subnetted networks.How will a packet arriving at the default gateway/router determine where it should go?
    It all comes down to the "network id"[net id] portion which makes it possible to locate the network.The packet would then traverse its way through a switch/hub to the appropriate host with the help of the host id.
    Always remember routers dont care about hosts,all they care about is segmented networks.
    I hope this helps.
     
  3. OP
    iinfi

    iinfi mekalodu

    Joined:
    Oct 22, 2004
    Messages:
    1,534
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Navi Mumbai
    thanks for your reply ...
    i had seen this in my book also .....
    class A supports 16,777,216 hosts per network ..
    class B supports 16,384 hosts per network .
    class C 256 ....

    now how do u arrive at these figures (in bold .)...?
     
  4. digen

    digen New Member

    Joined:
    Feb 8, 2004
    Messages:
    745
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Belgaum
    Hmm although I suck when it comes to math I will try my level best here :)

    As i've already explained Class A is Network.Node.Node.Node

    Now what is a IP address? Its a 32 it[4 byte] long address.
    What does this mean?Each byte is equal to 8 bits.
    Thus how many node addresses can the Class A address have?
    2^24 [i.e 2 raise to the power 24]Why because the first byte makes the network id,the rest three bytes make the host id which equals to 24bits.So you want to find the hosts aint it?
    2^24=16,777,216
    You may ask why 2 raise to n? Simple because a bit is either a 1 or a 0.

    Similarly just follow the network classes classification for Class B & Class C & you will finally end at those numbers without any confusion.
     
  5. OP
    iinfi

    iinfi mekalodu

    Joined:
    Oct 22, 2004
    Messages:
    1,534
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Navi Mumbai
    hi network guru
    thanks for your help ..... will trouble u if i have any further confusion...
     
Thread Status:
Not open for further replies.

Share This Page