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IP address range

Posted on 2011-11-01
Medium Priority
Last Modified: 2012-05-12

I am currently looking at setting up my own small office.  I have been sent my network details by the building management company:

DHCP addresses:
Local Network:
Gateway IP:

The management company has informed me i have 2 dhcp addresses and up to 13 additional IPs.
 Looking at the above IP details, would i simply use upwards?  Im slightly confused by the 'Local Network address'.  All other details im fine with.

The management company IT guy is away on holiday and i could do with getting up and running.

Many Thanks
Question by:support360

Accepted Solution

haoss earned 252 total points
ID: 37061701
here is /28 subnet description
you have 16 addresess 14 of them usable
gataway is .193 and DHCP are .194-.195 that means you have left with addreses from .196 - .206

Expert Comment

ID: 37061703
LVL 37

Assisted Solution

by:Neil Russell
Neil Russell earned 248 total points
ID: 37061719

As your Gateway IP is, you cant assign that so you can use .194 through to .206 BUT .194 and .195 have reserved for DHCP address so you must NOT statically assign those.

you can have 2 machines connected via DHCP , .194 and .195 and upto 11 machines with a static IP in the rance of .196-.206
LVL 21

Expert Comment

ID: 37061745
I make it 16 addresses, ( through inclusive) 2 of which are not available (first and last), leaving 14 for you to use.

193 is the gateway
194 and 195 are DHCP

You can use 196 through 206 inclusive for other (internal) machines.

To work it out, you have to think in bits.

The /28 means that you must match the first 28 out of 32 bits of the IP address.

An IP4 address is four numbers, 0 up to 255 each.  2^8 = 256, so those four numbers make 2^32 combinations (32 bits).

Yuo have to match the first 28 bits, and can vary the remaining 4 which is (in binary):

0000101000001000001001101100 - 0000
0000101000001000001001101100 - 1111

If you convert those to four sets of 8 bits, and convert those 8 bit numbers to decimals you get:



Author Closing Comment

ID: 37061749
Thanks Guys.  Seems very straight forward when explained.

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