Subnetting

[slowimport96]

How come most of the Subnetting books state you cant use subnet Zero, but you can?

[AbecX]

Wrong forum, so no answer from the Internet God.

[White_lightning]

because up untill recently you couldnt. Older router IOS didnt support routing 0.x.x.x.

but thats just a random guess.

[V-SICK]

Any body have a WEP Key I can borrow ?

[Shoot To Kill]

Any body have a WEP Key I can borrow ?
10 bucks and it's yours for life.

[Mustangman_2000]

yes, you can use a subnet zero.

old school IT teaches you not to subnet zero because you should not assign all zeros to a physical subnet. having all zeros makes them numerically indistinguishable.

in theory...

however, even though you can use a subnet zero, i would recommend that your answer be no if you run across it on a networking exam.

[AbecX]

abecx.net is on subnet 0.0.0.0

:O

Possible yes, smart, fuck no.

[slowimport96]

yes, you can use a subnet zero.

old school IT teaches you not to subnet zero because you should not assign all zeros to a physical subnet. having all zeros makes them numerically indistinguishable.

in theory...

however, even though you can use a subnet zero, i would recommend that your answer be no if you run across it on a networking exam.


Cool, Thanks
I usually just assign router interfaces the first or last usable address anyway.

[line-em-up]

Why would you want to use a zero subnet?

[AbecX]

Why would you want to use a zero subnet?
so you can put windows boxes on the network and see how long it takes for them to find each other via netbios.

[Mustangman_2000]

Why would you want to use a zero subnet?

it's typically not done to avoid confusion when setting up a network, but some people like to do it just because they can.

many network admins don't consider submit zero a legal subnet.

[Osiris]

Any body have a WEP Key I can borrow ?


Damn you're irritating.

[ceyko]

Prior RFCs stated that the first/last subnets should not be used at all. As of around 2000/2001 the newer RFCs state it is okay to use.

For exam purposes the answer is NO - although newer IOS comes standard with ip subnet-zero in the config. In the past you had to specifically type in that command.

Also in the past, even though the first/last were okay via RFCs - some gear was either bugged if you did it or they'd reject it. That's no longer an issue at all.

MM2000, I'm curious what Network guys worth a damn don't consider the first/last subnet....usuable in most situations.

Take care,