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I am designing a small network and have came up with the following table I am just wondering if this seems right, would appreciate some feedback, thanks.

Network/Router    First IP    Last IP   Subnet             Host         Broadcast

Router 1          162.10.0.1  162.10.0.7   255.255.255.248 162.10.0.0   162.10.0.8
Network 1         162.10.1.1  162.10.2.253 255.255.254.0   162.10.1.0   162.10.2.254
Network 2         162.10.0.9  162.10.0.14  255.255.255.248 162.10.0.8   162.10.0.15
Router 2          162.10.0.17 162.10.0.18  255.255.255.252 162.10.0.16  162.10.0.19
Network 3         162.10.0.21 162.10.0.146 255.255.255.128 162.10.0.20  162.10.0.147

Router one is the IP assigned by the ISP

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closed as not constructive by EEAA, Scott Pack, Ward, Skyhawk, Khaled Apr 13 '12 at 6:03

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1 Answer 1

Network/Router    First IP    Last IP   Subnet             Host         Broadcast

Change the host label to Network or network ID, that would be more accurate. Calling those addresses a host address doesn't make any sense. The Network ID, or Network Address, is the address within a subnet where all the host bits are zero.

Network 3         162.10.0.21 162.10.0.146 255.255.255.128 162.10.0.20  162.10.0.147

Sorry, but this one is wrong. There is no way you can take a /25 chunk out of the middle like that. The arithmetic, simply doesn't work out that way. If you need a /25 you only have 2 choices.

162.10.0.1   162.10.0.126 255.255.255.128 162.10.0.0    162.10.0.127
162.10.0.129 162.10.0.254 255.255.255.128 162.10.0.128  162.10.0.255

Address:   162.10.0.0           10100010.00001010.00000000.0 0000000
Netmask:   255.255.255.128 = 25 11111111.11111111.11111111.1 0000000
Wildcard:  0.0.0.127            00000000.00000000.00000000.0 1111111
Network:   162.10.0.0/25        10100010.00001010.00000000.0 0000000
HostMin:   162.10.0.1           10100010.00001010.00000000.0 0000001
HostMax:   162.10.0.126         10100010.00001010.00000000.0 1111110
Broadcast: 162.10.0.127         10100010.00001010.00000000.0 1111111

Address:   162.10.0.128         10100010.00001010.00000000.1 0000000
Netmask:   255.255.255.128 = 25 11111111.11111111.11111111.1 0000000
Wildcard:  0.0.0.127            00000000.00000000.00000000.0 1111111
Network:   162.10.0.128/25      10100010.00001010.00000000.1 0000000
HostMin:   162.10.0.129         10100010.00001010.00000000.1 0000001
HostMax:   162.10.0.254         10100010.00001010.00000000.1 1111110
Broadcast: 162.10.0.255         10100010.00001010.00000000.1 1111111

Network 1         162.10.1.1  162.10.2.253 255.255.254.0   162.10.1.0   162.10.2.254

Sorry, this one won't work either. A /23 that included the address 162.10.1.1 would need to start at 162.10.0.1, and go to 162.10.1.254. Like this.

Address:   162.10.0.0           10100010.00001010.0000000 0.00000000
Netmask:   255.255.254.0 = 23   11111111.11111111.1111111 0.00000000
Wildcard:  0.0.1.255            00000000.00000000.0000000 1.11111111
=>
Network:   162.10.0.0/23        10100010.00001010.0000000 0.00000000
HostMin:   162.10.0.1           10100010.00001010.0000000 0.00000001
HostMax:   162.10.1.254         10100010.00001010.0000000 1.11111110
Broadcast: 162.10.1.255         10100010.00001010.0000000 1.11111111

So to summarize, you have a lot of impossible subnets on that table. You need to take some time, and go back to the subletting fundamentals.

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So if router 1 has the ip address 162.10.0.0, how can the network address of network 1 be the same? –  mitchnufc Apr 12 '12 at 17:28
    
I understand the network 3 problem as I would have to start with the largest first then break it down from there –  mitchnufc Apr 12 '12 at 17:29
    
@mitchnufc, not sure were you are seeing me suggest a router address of 162.10.0.0. That would not be a valid IP address that could be assigned to a host unless you had a mask between /1 and /14. –  Zoredache Apr 12 '12 at 17:46
    
SO i could use Router 1 address 162.10.0.0, then network 1 162.10.0.1/23 - 162.0.1.254/23 with the Host address 162.10.0.0 and the broadcast 162.10.0.2545 –  mitchnufc Apr 12 '12 at 17:57
    
What do you think the word host means? Calling 162.10.0.0 a host address doesn't make any sense. A host is just a computer or a system. A host address would be a valid IP that could be assigned to a computer. As I mentioned 162.10.0.0 isn't a valid IP, unless you have a really large network, but what actually could be is a NETWORK ID, or Network address. A network address the address where all the host bits are 0. –  Zoredache Apr 12 '12 at 18:10

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