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Harold Ritter Sat, 03/18/2006 - 12:30
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  • Cisco Employee,

The network address would be 10.0.0.0/8 if you take in consideration the classful model. The subnet address would be 10.144.32.0/23.


Hope this helps,

akachroo123 Sat, 03/18/2006 - 12:57
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I was basically calculating it wrongly.Now i have found it.

Thanks a lot.

insccisco Sat, 03/18/2006 - 19:43
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Hi,


but how did you come to this info? can you show the formula on how you solve this?


I am new to this and I want to learn, so excuse my ignorance


thanks

Harold Ritter Sat, 03/18/2006 - 20:11
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To obtain the subnet number, you need to consider only the bits dictated by the subnet mask from the IP address as follow:

10.144.33.254/23 (IP address and subnet mask)


0000 1010.1001 0000.0010 0001.1111 1110 (IP address)

1111 1111.1111 1111.1111 1110.0000 0000 (subnet mask)


0000 1010.1001 0000.0010 0000.0000 0000 (resulting subnet number in binary)


10.144.32.0 (resulting subnet number in decimal)


Hope this helps,

insccisco Sat, 03/18/2006 - 21:30
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"To obtain the subnet number, you need to consider only the bits dictated by the subnet mask from the IP address as follow: "


That's exactly my problem. When given only 10.144.33.254/23, I don't know how to read this. So far I know 10.144.33.254 is the IP address, but the slash (/) throws me off... and the 23, I don't remember how to use it


How do you know 1111 1111.1111 1111.1111 1110.0000 0000 (255.255.254.0) is the subnet mask?


pkhatri Sun, 03/19/2006 - 00:11
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Hi,


The number after the slash signifies the length of the mask. To convert this number to a subnet mask, simply write down that number of 1s, followed by a number of zeros until you have 32 digits in total. For the /23, that gives you:

1111 1111.1111 1111.1111 1110.0000 0000


Note that there are 23 ones followed by 9 zeros.


If you now convert each of the 8-bit blocks into decimal, you get 255.255.254.0


Hope that helps - pls rate the post if it does.

Paresh

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