# How many broadcast domains are there in a 12-port router?

Just one broadcast domain How many broadcast domains and collision domains are there on a standard 12-port half-duplex switch? "B" is the right answer. The switch establishes 12 collision domains and one broadcast domain. A collision domain is a group of ports that use inter-frame spacing to determine which frames are received on each port.

A broadcast domain is a group of ports that pass all broadcast packets sent their way. A switch automatically creates a broadcast domain for each broadcast address assigned to it. A broadcast address is an IP address assigned to a network segment that sends any packet destined for another host on that network back to everyone on the entire subnet. A host can receive messages sent by other hosts on the same subnet but cannot send any messages itself. Broadcast traffic includes ARP requests and responses, TCP/IP, ICMP, and others.

Since a switch creates a single broadcast domain, we can reduce the number of broadcast domains required on a switch by using multiple switches or VLANs. For example, if we have two switches connected by a link, they will have four broadcast domains: one from each switch. If we assign separate broadcast addresses to each switch, they can communicate without interfering with each other's broadcasts.

## How many broadcast domains are created when you segment a network with a 12 port switch?

When you segment a network with a 12-port switch, how many broadcast domains are created? Explanation: Switches, by default, divide collision domains but combine them into a single huge broadcast domain. 18.0/12 = 1.5. The number of broadcast domains equals the logic level of the link; in this case, half. Each segment represents one broadcast domain.

Here's how to calculate the number of broadcast domains on a network divided into two segments connected by a 12-port switch:

First, determine the number of ports on the switch. In this case, it is 12. Next, count up the number of broadcast domains across both segments. Since there are six bits in a broadcast address, that means each byte has two broadcast addresses. Byte 0 contains the broadcasts for the first segment, while byte 1 contains those for the second. There are two ways to do this: You can either examine all the ports on the switch and count how many have traffic or use the quick check method and just see which ports have active connections.

In this case, we'll use the quick check method and only look at the set of working ports. That is, those with active connections. This reduces the number of broadcasts needed because only addresses within range on these ports will be sent out onto the network.

## How many broadcast domains are there on the switch?

The number of collision domains on a switch is equal to the number of ports on the switch, but it only has one broadcast. As a result, if a switch has 24 ports, it has 24 collision domains and one broadcast domain. A broadcast frame sent by port 1 will be received by all other ports.

## How many broadcast domains are in a 48-port switch with 24 active Vlans?

Because every port on the switch is a collision domain, there will be 48 collision domains. Because each vlan is a broadcast domain, there will be five broadcast domains. There are two ways to answer this question: mechanically or computationally.

Mechanically, we can say that there are two broadcasts for every data packet sent out. This is because each packet has a source address and a destination address. If we were to send a packet with its destination address being itself, it would be considered a broadcast because it would reach all devices on the network.

Computationally, we can say that there are two broadcasts for every data packet sent out because each packet has a source address and a destination address.

In conclusion, there are two broadcasts for every data packet sent out by a switch with VLANs enabled.

##### Donald Rook

Donald Rook is a software engineer who's passion is building things. He has over 10 years of experience in the industry and has been working with Rails since 2008. If he isn't working on his projects, Donald enjoys reading, going to the gym, and spending time with his wife and two sons.