We help IT Professionals succeed at work.

subnetting

263 Views
Last Modified: 2013-11-16
Hi,,

i am little bit confused about using ip range.  for example i have 3 sites with 200 nodes on each site. so i need three networks connected with router

can i use 192.168.10.0/24   192.168.11.0/24    192.168.13.0/24    networks....

or should use private b class ip and subnet.

thanks..

F
Comment
Watch Question

The 3 you mentioned are fine. They are private subnets.
EricSystem Admin

Author

Commented:
thanks,, okay,,what if i need more then 250 nodes on one site.  what can i do for that site..

and will you tell me please,, why some companies use public ip s in their internal network.. i thought internal networks better use private networks
If you want more than 250 or more than a /24 can hold then just exspand the subnet range by changing the subnet mask. if you go to a /23 mask (255.255.254.0) then you can have up to 510 ips.
here is a good tool to use when working with subnetting.
http://www.subnet-calculator.com/
 
using a public IP for internal server is usually only used when those servers manage web services such as web sites or e-commerce servers.
there are several reasons (that i can think of off the top of my head) that you would use a public IP for these servers:
1) You can advertise the server to multiple ISPs or through BGP so that the whole internet knows how to get to that specific server directly instead of through 1 ISP.
2) With private IPs you must NAT your public ip to a private ip. this causes extra resource usage and a small amount of delay when the router must translate the address. With high traffic web sites or delay sensitive applications NAT would not be a good option.
EricSystem Admin

Author

Commented:
i see,, then i can use 192.168.10.0/24 and 192.168.11.0/24 and 192.168.12.0/23


right ?
yes your thrid range will be 192.168.12.1 - 192.168.13.255
Just watch out for the range you select. How subnetting works you wouldnt be able to use the range 192.168.13.1 - 192.16.14.255. they split up in groups so you could only use 12.1 - 13.255 and then 14.1 - 15.255.
hope that makes sense. That is why i recommend playing around with the calculator i linked to. give you all the info you need.
EricSystem Admin

Author

Commented:
thanks for your input but let me ask you this

 those kind of server ( web , dns, e-commerse ) are generally place in dmz and they can still use private ips for security , i guess or just use public ips.

but why would you want to use public ips for your intranet such as for your desktops etc...for the same NAT reason may be ?

thanks

F.


using a public IP for internal server is usually only used when those servers manage web services such as web sites or e-commerce servers.

there are several reasons (that i can think of off the top of my head) that you would use a public IP for these servers:

1) You can advertise the server to multiple ISPs or through BGP so that the whole internet knows how to get to that specific server directly instead of through 1 ISP.

2) With private IPs you must NAT your public ip to a private ip. this causes extra resource usage and a small amount of delay when the router must translate the address. With high traffic web sites or delay sensitive applications NAT would not be a good option.
"but why would you want to use public ips for your intranet such as for your desktops etc...for the same NAT reason may be"
I have no clue why someone would use a public ip for internal workstations. Its a waste of an external IP and provides no additional functionality. NAT can provide all the resources for workstations that a end-user would need.
EricSystem Admin

Author

Commented:
yes,, but i have seen environment like that.

thanks .
This one is on us!
(Get your first solution completely free - no credit card required)
UNLOCK SOLUTION
EricSystem Admin

Author

Commented:
thanks..this subnetting i understand little bit not much.

anyway i just use then 192.168.10 and 11/24 for 2 sites
and 12.1 - 13.255 range  for the last site/

thanks again



yes your thrid range will be 192.168.12.1 - 192.168.13.255

Just watch out for the range you select. How subnetting works you wouldnt be able to use the range 192.168.13.1 - 192.16.14.255. they split up in groups so you could only use 12.1 - 13.255 and then 14.1 - 15.255.

hope that makes sense. That is why i recommend playing around with the calculator i linked to. give you all the info you need.
Unlock the solution to this question.
Join our community and discover your potential

Experts Exchange is the only place where you can interact directly with leading experts in the technology field. Become a member today and access the collective knowledge of thousands of technology experts.

*This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

OR

Please enter a first name

Please enter a last name

8+ characters (letters, numbers, and a symbol)

By clicking, you agree to the Terms of Use and Privacy Policy.