Which command is used to configure an IRB interface?

B

An IRB interface is configured similar to a physical Layer 3 interface, by specifying an interface type irb, a logical unit, a protocol family, and an IP address (using

CIDR notation).

The correct answer is B.

Explanation:

An Integrated Routing and Bridging (IRB) interface is a virtual Layer 3 interface that connects a Layer 2 bridge domain with a Layer 3 routing instance. It allows Layer 3 routing protocols to communicate with Layer 2 bridging domains.

The command to configure an IRB interface is:

kotlinCopy code
set interface irb unit 0 family inet address 192.168.1.1/24 

Let's break this command down:

• set: This is the Junos command to enter configuration mode.
• interface irb: This specifies the interface type as IRB.
• unit 0: This specifies the unit number for the IRB interface. By default, the unit number is 0.
• family inet: This specifies the address family for the IRB interface as IPv4.
• address 192.168.1.1/24: This sets the IP address and subnet mask for the IRB interface.

Option A is incorrect because it uses the set command to configure the address on the interface directly, without specifying the interface type. Option C is also incorrect because it uses the family irb command, which is not a valid configuration command. Option D is incorrect because it uses the bridge-domain command, which is not necessary for configuring an IRB interface.