Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Whats the meaning of 10.0.0.1/24 address of my computer (ip addr - command)?

  1. 1/24 and not 0/8

  2. 10.0.0 range and not 192.168.10

share|improve this question
    
if your computer is getting the address via dhcp, it means that the "box" handing out ip's is set up to use the 10 net. some soho routers use this, most use 192.168.?.0 /24. –  dbasnett Jun 30 '10 at 13:49
add comment

3 Answers

up vote 10 down vote accepted

Thought I would expand on this with a few examples

/8 = 255.0.0.0

/16 = 255.255.0.0

/24 = 255.255.255.0

/32 = 255.255.255.255

192.168.1.0/24 = 192.168.1.0-192.168.1.255

192.168.1.5/24 is still in the same network as above we would have to go to 192.168.2.0 to be on a different network.

192.168.1.1/16 = 192.168.1.0-192.168.2.255

When you have a network you lose two IP addresses one for broadcast and one for the network. The first IP is reserved to refer to the network while the last ip of the range is reserved for the broadcast address.

share|improve this answer
    
Thank you very much! –  Yosef Jun 29 '10 at 21:40
    
According to RFC1878 "*Subnet all zeroes and all ones excluded. (Obsolete) *Host all zeroes and all ones excluded. (Obsolete) –  dbasnett Jul 1 '10 at 13:12
    
@chris isn't 192.168.1.1/16 = 192.168.0.0-192.168.255.255 ? –  Rajani Karuturi May 6 at 15:08
add comment

In addition to Tim's answer:

The /24 instead of /8 means that the first 3 octets of the ip address are used to specify the network. This is just a setting you can change if you want to. It's not super common to use the 10. private range with a /24 mask but there's no reason you can't do it.

/8 is using only the first octet to specify the network portion, which is what a 10. network explicitly meant back in the pre-CIDR days, and that's why you still see it more often with a /8 than with a 24.

As for the last octet being a 0 not a 1, that's because a 10.0.0.0 would in this case be the network address, with 10.0.0.1 being your computers ip.

share|improve this answer
    
Thank you very much! –  Yosef Jun 29 '10 at 21:40
add comment

RFC 1918 reserves 3 ranges for private IP addresses. Your DHCP server/router is configured to assign this range.

10.0.0.0 - 10.255.255.255/8

172.16.0.0 - 172.31.255.255/12

192.168.0.0 - 192.168.255.255/16

http://en.wikipedia.org/wiki/Private_network

share|improve this answer
    
Thanks for answer 2, What about number 1. 1/24 etc... –  Yosef Jun 29 '10 at 20:02
    
Sorry, didn't see that part. Dmatig answered above :-) So, your ip address is 10.0.0.1 and the /8 subnet mask or 255.255.255.0 –  TD1 Jun 29 '10 at 20:28
    
I think you got the /8 and /24 from the post switched around /24 is 255.255.255.0 /8 is 255.0.0.0 :) –  Chris Disbro Jun 29 '10 at 21:02
    
Thanks,Can you please explain to me more simple I dont know networks –  Yosef Jun 29 '10 at 21:05
    
see superuser.com/questions/54802/… A subnet mask can also be represented in CIDR notation, like /8. /8 means 255.0.0.0 because the first 8 bits equal 255. (think 8 binary 1's). Now from left to right if 24 binary ones and 8 0's were used we'd get /24 - 255.255.255.0 –  Dmatig Jun 29 '10 at 21:08
show 1 more comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

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