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Trying to Understand IP Addresses

I've been studying routing, and although I feel like I have a basic idea of routing and the different protocols associated with it, I've always had this IP address question.

If I you are given the whole network 70.70.0.0/16 by your ISP (I'm using classful addresses to keep it real simple), than why can't that same ISP give someone else the network 70.70.0.0/24.

Since the first network has a 70.70.0.0/16 address, and the other network would have a 70.70.0.0/24 network, wouldn't that mean that it's a whole separate network since the netmasks are different. I know you can't assign those two networks out to two separate companies, but can someone explain why? Thanks!

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VIP Purple

Re: Trying to Understand IP Addresses

One single public IP is not allowed to be on different networks. Each public IP has to be unique on the internet.


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3 REPLIES
VIP Purple

Trying to Understand IP Addresses

The network 70.70.0.0/16 includes the range 70.70.0.0 to 70.70.255.255 while network 70.70.0.0/24 includes the range 70.70.0.0 to 70.70.0.255. There you can see that 70.70.0.0/24 is part of 70.70.0.0/16 and you can't give it to a different customer.

-- 
Don't stop after you've improved your network! Improve the world by lending money to the working poor:
http://www.kiva.org/invitedby/karsteni


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Don't stop after you've improved your network! Improve the world by lending money to the working poor: http://www.kiva.org/invitedby/karsteni
New Member

Re: Trying to Understand IP Addresses

Bu isn't it on whole separate network if you have the address 70.70.0.50 with a netmask of /24 vs an address of 70.70.0.50 with a netmask of /16. Aren't those ip addresses different since they're on two different networks?

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VIP Purple

Re: Trying to Understand IP Addresses

One single public IP is not allowed to be on different networks. Each public IP has to be unique on the internet.


--
Don't stop after you've improved your network! Improve the world by lending money to the working poor:
http://www.kiva.org/invitedby/karsteni


--
Don't stop after you've improved your network! Improve the world by lending money to the working poor: http://www.kiva.org/invitedby/karsteni
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