thinQmaster Virtual testing partner Adaptive practice exams that find your weak spots and drill them. Every answer explained. From $69
Enroll

thinQmaster

Find your exam

Five questions free, before you decide.

Step 1 · choose a vendor

In one of our camps? Your practice exams come with the tuition — they are on your study page already.

Networking Fundamentals · Intermediate

Limited Broadcast

The address 255.255.255.255, which reaches all hosts on the local segment and is never forwarded by routers.

Definition

A host uses limited broadcast when it does not know its own network, such as a DHCP client sending a DHCPDISCOVER from 0.0.0.0 to 255.255.255.255. Routers block it, which is why DHCP relay agents are needed when the server is on another subnet.

Example

A DHCPDISCOVER has destination IP 255.255.255.255 and destination MAC ff:ff:ff:ff:ff:ff.

Exam tip

Routers do not forward broadcasts; that is why each router interface defines a separate broadcast domain.

Related terms