Gateway Load Balancing Protocol (GLBP) routers communicate between each other via what multicast address?
A) 224.0.0.102
B) 224.0.0.10
C) 224.0.0.0
D) 223.0.0.10
The correct answer and explanation is:
The correct answer is A) 224.0.0.102.
Explanation:
The Gateway Load Balancing Protocol (GLBP) is used to provide automatic load balancing and redundancy for IP networks. It allows multiple routers to work together and share the traffic load for a given virtual IP address, making it a highly available gateway solution.
In GLBP, the participating routers communicate with each other using a multicast address to share information such as the virtual gateway’s state, roles, and load balancing status. The specific multicast address used by GLBP routers to communicate with each other is 224.0.0.102. This address is reserved for GLBP routers within the local subnet, and it ensures that only GLBP routers participate in the exchange of load-balancing information.
This multicast address is a part of the IPv4 Class D range (224.0.0.0 to 239.255.255.255), which is designated for multicast communication. GLBP routers use this address to send messages to all other routers participating in the GLBP group. When a router sends a message to 224.0.0.102, only the routers that are configured to use GLBP and belong to the same GLBP group will receive and process the message.
The other options, such as 224.0.0.10 and 224.0.0.0, are reserved for different purposes. For instance, 224.0.0.10 is used for Routing Information Protocol (RIP) version 2 communication, and 224.0.0.0 is not a valid address for GLBP communication.
By using this dedicated multicast address, GLBP ensures that the load balancing and failover processes are efficiently managed without interfering with other network services.