Clustering information on ip address failover

      15

In a same block of IPv4 addresses, can there be same IPs with different submasks?For example, can I have this:

180.70.65.140/26180.70.65.140/25180.70.65.140/24All the 3 addresses above have the same numbers but different subnet mask. Are all the 3 addresses distinct of their own? In other words, 180.70.65.140/25 belongs to User A, 180.70.65.140/25 belongs to lớn User B và 180.70.65.140/24 belongs to User C?

After applying the submask, their network addresses look lượt thích this:

180.70.65.140/26 --> 180.70.65.128/26180.70.65.140/25 --> 180.70.65.128/25180.70.65.140/24 --> 180.70.65.0/24If the addresses are recognised uniquely, how is it so? How would each of the these addresses being recognised to be unique?

I am thinking like once I have 180.70.65.140/26, I can"t reuse the same numbers of 180.70.65.140 again but since classless is meant lớn increase the number of IP addresses, it would vày much if I can"t reuse.


chia sẻ
Improve this question
Follow
edited Apr 13, 2017 at 12:14
*

CommunityBot
1
asked Nov 16, 2011 at 8:25

xenonxenon
29122 gold badges66 silver badges1111 bronze badges
0
add a phản hồi |

3 Answers 3


Sorted by: Reset to default
Highest score (default) Date modified (newest first) Date created (oldest first)
15
There are numerous reasons, but the simplest is that this will break any routing, because a host will have no way of knowing that they"re going lớn an address on a different network.

So, basically, no. An IP address needs lớn be unique, regardless of subnet.

In other words, if I"m on

192.168.1.1255.255.0.0

And I try to lớn access 192.168.1.2, then it"s going khổng lồ assume it"s on the same subnet.

On a fundamental level, subnets are there khổng lồ separate broadcast domains and improve efficiency. They"re not for sharing IP addresses.


giới thiệu
Improve this answer
Follow
answered Nov 16, 2011 at 8:27
*

DanDan
15.3k11 gold badge3636 silver badges6767 bronze badges
showroom a bình luận |
4
As an answer to lớn your question above, the answer is: No you can"t... It is the address itself that must be unique.

The IP(v4) address in each of the three examples would be: 180.70.65.140 (regardless of subnet mask)

The subnet mask can be thought of as: "what defines the limits of my LOCAL network"In order khổng lồ reach any IP outside of this range, the computer would need to liên hệ the "gateway" khổng lồ pass the IP-packet to an external route.

So, for example

180.70.65.140/26 just means that IPs 180.70.65.129 -> 180.170.65.191 are accessible 180.70.65.140/25 just means that IPs 180.70.65.129 -> 180.170.65.255 are accessible 180.70.65.140/24 just means that IPs 180.70.65.1 -> 180.170.65.255 are accessible

Wikipedia has a reasonable links here


nội dung
Improve this answer
Follow
answered Nov 28, 2011 at 23:35
*

Steven_WSteven_W
25233 silver badges1010 bronze badges
1
showroom a phản hồi |
0
The way I look at it is , your subnet specifications are like a venn diagram. The bigger subnets incompass the smaller subnets. So one IP could exist in all three subnets. So they vì chưng have be unique if they are all on the same machine & Vlan etc.


giới thiệu
Improve this answer
Follow
edited Nov 16, 2011 at 9:15
answered Nov 16, 2011 at 8:52
*

AndyMAndyM
90322 gold badges1414 silver badges2626 bronze badges
địa chỉ cửa hàng a comment |
Not the answer you're looking for? Browse other questions tagged or ask your own question.
The Overflow Blog Featured on Meta
Linked
472
How does IPv4 Subnetting Work?
Related
472
How does IPv4 Subnetting Work?
132
How does IPv6 subnetting work and how does it differ from IPv4 subnetting?
2
Why do all computers on my network have the same MAC address?
0
In the routing decision, why is only the source's subnet mask used & applied khổng lồ both source IP và destination IP?
0
confused about CIDR interpretation
Hot Network Questions more hot questions
hệ thống Fault
Company
Stack Exchange Network

Site kiến thiết / logo © 2022 Stack Exchange Inc; user contributions licensed under CC BY-SA. Rev2022.10.31.43000


Your privacy

By clicking “Accept all cookies”, you agree Stack Exchange can store cookies on your device và disclose information in accordance with our Cookie Policy.