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Using IP Subnet-zero? in which case is this cmd beneficial?
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| I have been asked what exactly does ip subnet-zero does? I answered that it enable you to use subnet 0 on an interface. Also, I believe that you may use all available subnets all 1's. Can anyone explain further, maybe a simpler answer.. | |
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| You've always been able to use the all ones subnet on an interface, it's just not a good idea sometimes. ip subnet-zero just allows you to use the all-zeros subnet on an interface. If I understand your question, I believe you answered correctly. You would use this anytime you needed to use the all zeros subnet, say if you needed assign the address 10.1.1.1 255.255.255.192 to an interface. Nothing too special about that.
MadChef | |
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| The problem from all using all zero subnet is that it is very proprietary and if have any other devices other that Cisco on your network then they won't be able to communicate
Lawrence CCNA MCSE NSNS A+ N+ www.nacse.com | |
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| lawrencej makes a good point. subnet zero became an option (in general networking, not the cisco command) only after CIDR became established. Many older devices may not be happy with using these addresses but I would imagine that most have been patched to fix this. This whole subject was brought to my attention initially because HP-UX 10.something wouldn't allow you to give it an address in the zero subnet without first patching the OS.
I wouldn't say that it's proprietary so much that it is not ubiquitous. Once CIDR came along, there was no such thing as an all ones or all zero subnet since there weren't classfull addresses anymore. Any device that supports CIDR should be just fine with this.
MadChef
[This message has been edited by MadChef (edited 10-24-2000).] | |
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| ip subnet-zero in a simpler term allows you the administrator to issue the first available subnets that in past due to classful routing techniques were wasted because the router didnt know how distributed those available subnets.It would also be good a suggestion to have ip classless enable also.
Lcooper
ccna,ccda | |
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| Thank you guys for your input. Madchef, very informative stuff! Where do you get all this info? | |
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| Experience. The more you do this stuff the more you pick up along the way.
MadChef |
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