Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

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
Network 1
Network 2
Router 2
Network 3

Router one is the IP assigned by the ISP

share|improve this question

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

As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, visit the help center for guidance.If this question can be reworded to fit the rules in the help center, please edit the question.

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

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.

Address:           10100010.00001010.00000000.0 0000000
Netmask: = 25 11111111.11111111.11111111.1 0000000
Wildcard:            00000000.00000000.00000000.0 1111111
Network:        10100010.00001010.00000000.0 0000000
HostMin:           10100010.00001010.00000000.0 0000001
HostMax:         10100010.00001010.00000000.0 1111110
Broadcast:         10100010.00001010.00000000.0 1111111

Address:         10100010.00001010.00000000.1 0000000
Netmask: = 25 11111111.11111111.11111111.1 0000000
Wildcard:            00000000.00000000.00000000.0 1111111
Network:      10100010.00001010.00000000.1 0000000
HostMin:         10100010.00001010.00000000.1 0000001
HostMax:         10100010.00001010.00000000.1 1111110
Broadcast:         10100010.00001010.00000000.1 1111111

Network 1

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

Address:           10100010.00001010.0000000 0.00000000
Netmask: = 23   11111111.11111111.1111111 0.00000000
Wildcard:            00000000.00000000.0000000 1.11111111
Network:        10100010.00001010.0000000 0.00000000
HostMin:           10100010.00001010.0000000 0.00000001
HostMax:         10100010.00001010.0000000 1.11111110
Broadcast:         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.

share|improve this answer
So if router 1 has the ip address, 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 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, then network 1 - with the Host address and the broadcast – mitchnufc Apr 12 '12 at 17:57
What do you think the word host means? Calling 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 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

Not the answer you're looking for? Browse other questions tagged or ask your own question.