Zero Subnet needs explaining to me?

BeanyBeany Member Posts: 177
in CCNA & CCENT
Morning,

is it just me or does everyone quite frequently come across some topics and think "what the f are you on about"? :)

Can someone please explain this topic to me? I've searched for this and still cant grasped the fundementals of Zero Subnet.

Maybe someone on this quality forum can provide a simple explanation for Zero subnet and allow me to move on with my studying.

thanks
· Share on FacebookShare on Twitter

Comments

  • jibbajabbajibbajabba Member Posts: 4,317 ■■■■■■■■□□
    Are you talking about the ip subnet-zero command ?

    It allows you to start at block zero in terms of available IP addresses (I think).

    When a /24 gives you 256 addresses for example, subnet-zero means you can start at 0 (0-255) rather than 256 ...

    I hope that makes sense (and is correct to begin with) - I am no Cisco monkey and I just remember a phone conversation I over-heard once ..
    My own knowledge base made public: http://open902.com :p
    · Share on FacebookShare on Twitter
  • atorvenatorven Member Posts: 319
    It's the very first subnet after subnetting(hope that makes sense) Take a look at the example below;
    192.168.0.0/24 <== subnet zero
    192.168.1.0/24
    192.168.2.0/24

    It will all become clear once you learn to subnet.
    · Share on FacebookShare on Twitter
  • DANMOH009DANMOH009 Member Posts: 241
    A quick way of me remembering is, If IP subnet zero is not configured, then we cant start at zero when counting the subnets involved.
    · Share on FacebookShare on Twitter
  • BeanyBeany Member Posts: 177
    DANMOH009 wrote: »
    A quick way of me remembering is, If IP subnet zero is not configured, then we cant start at zero when counting the subnets involved.

    So the command 'no ip subnet zero' is used when subnet zero is not configured/used?
    · Share on FacebookShare on Twitter
  • BeanyBeany Member Posts: 177
    atorven wrote: »
    It's the very first subnet after subnetting(hope that makes sense) Take a look at the example below;
    192.168.0.0/24 <== subnet zero
    192.168.1.0/24
    192.168.2.0/24

    It will all become clear once you learn to subnet.

    cool... so does the cisco devices by default allow us to use the subnet zero or do we have to manually configure the router?
    · Share on FacebookShare on Twitter
  • atorvenatorven Member Posts: 319
    Yes, by default most routers now days should have ip subnet zero turned on. If you don't want to use zero subnets then you turn it off by by issuing the no ip subnet zero command, from my studies so far I can't see what benefit you would gain by turning it off.
    · Share on FacebookShare on Twitter
  • FloOzFloOz Member Posts: 1,614 ■■■■□□□□□□
    I posted a very similiar question regarding subnet zero last week. here is the thread.
    http://www.techexams.net/forums/ccna-ccent/82174-subnet-zero-help.html
    · Share on FacebookShare on Twitter
  • BeanyBeany Member Posts: 177
    FloOz wrote: »
    I posted a very similiar question regarding subnet zero last week. here is the thread.
    http://www.techexams.net/forums/ccna-ccent/82174-subnet-zero-help.html

    Thanks for this
    · Share on FacebookShare on Twitter
Sign In or Register to comment.