Linux - NetworkingThis forum is for any issue related to networks or networking.
Routing, network cards, OSI, etc. Anything is fair game.
Notices
Welcome to LinuxQuestions.org, a friendly and active Linux Community.
You are currently viewing LQ as a guest. By joining our community you will have the ability to post topics, receive our newsletter, use the advanced search, subscribe to threads and access many other special features. Registration is quick, simple and absolutely free. Join our community today!
Note that registered members see fewer ads, and ContentLink is completely disabled once you log in.
If you have any problems with the registration process or your account login, please contact us. If you need to reset your password, click here.
Having a problem logging in? Please visit this page to clear all LQ-related cookies.
Get a virtual cloud desktop with the Linux distro that you want in less than five minutes with Shells! With over 10 pre-installed distros to choose from, the worry-free installation life is here! Whether you are a digital nomad or just looking for flexibility, Shells can put your Linux machine on the device that you want to use.
Exclusive for LQ members, get up to 45% off per month. Click here for more info.
A broadcast address is the address used to broadcast packets to every client on the LAN. The broadcast address is always the highest number possible in a particular subnet.
A broadcast address is a logical address at which all devices connected to a multiple-access communications network are enabled to receive datagrams. A message sent to a broadcast address may be received by all network-attached hosts.[1]
You NIC setup looks correct provided the gateway is 126.
In a subnet you have the network address, which is the first IP Address, that can never be used and a broadcast address, which is the last IP Address, that also can never be assigned. That is why yopu see when referencing subnets are N-2 for usable addresses.
Take for example your subnet /26. That has 64 total addresses but only 62 are usable because the network identifier (172.25.1.64) and the broadcast (172.25.1.127) cannot be used leaving 65-126 usable. Looks like the network admin has chosen 172.25.1.126 as the gateway for this network.
If you read the Wikipedia article 255.255.255.255 is a special definition. In addition from the same article...
Quote:
The broadcast address for an IPv4 host can be obtained by performing a bitwise OR operation between the bit complement of the subnet mask and the host's IP address. In other words, take the host's IP address, and set to '1' any bit positions which hold a '0' in the subnet mask. For broadcasting a packet to an entire IPv4 subnet using the private IP address space 172.16.0.0/12, which has the subnet mask 255.240.0.0, the broadcast address is 172.16.0.0 | 0.15.255.255 = 172.31.255.255.
As stated it is the highest possible address in the subnet. From the image posted your subnet is defined as
172.25.1.64/26 (255.255.255.192) broadcast 172.25.1.127
This means the range is 172.25.1.64 - 172.25.1.127. Since you can not use lowest or highest address i.e. one defines the subnet, the other the broadcast, the number of possible hosts is 62 i.e. 172.25.1.65 - 172.25.1.126.
LinuxQuestions.org is looking for people interested in writing
Editorials, Articles, Reviews, and more. If you'd like to contribute
content, let us know.