You are a network administrator configuring HSRP (Hot Standby Router Protocol) on your network’s routers to ensure high availability and reliability of your gateway. Which of the following statements about HSRP are true? (Choose two.)
a) HSRP allows multiple routers to share a virtual IP address.
b) The router with the highest priority becomes the active router.
c) HSRP is a Cisco proprietary protocol.
d) HSRP allows routers to dynamically share their MAC addresses.
e) The standby router will immediately take over if the active router fails.
Answer Options and Detailed Explanation:
Option a) HSRP allows multiple routers to share a virtual IP address.
- True.
- Detail: HSRP (Hot Standby Router Protocol) is designed to allow multiple routers to share a single virtual IP address. This virtual IP address acts as the default gateway for hosts on a local subnet. The primary benefit is that it provides high availability for IP traffic, ensuring that if the active router fails, the standby router can take over without disrupting the network traffic.
Option b) The router with the highest priority becomes the active router.
- True.
- Detail: Within HSRP, routers are assigned priorities. The router with the highest priority (a value between 0 and 255) becomes the active router. By default, the priority is 100, but this can be configured to ensure a particular router is preferred as the active router. If two routers have the same priority, the router with the highest IP address becomes the active router.
Option c) HSRP is a Cisco proprietary protocol.
- True.
- Detail: HSRP is indeed a Cisco proprietary protocol. It was developed by Cisco to provide high network availability by providing first-hop redundancy for IP hosts on a LAN configured with a default gateway. As a proprietary protocol, it is implemented primarily on Cisco devices, although some third-party vendors may support it through interoperability features.
Option d) HSRP allows routers to dynamically share their MAC addresses.
- False.
- Detail: HSRP does not dynamically share MAC addresses. Instead, HSRP uses a virtual MAC address that is associated with the virtual IP address. The active router responds to ARP requests for this virtual IP address with the virtual MAC address. When the standby router takes over, it assumes the virtual MAC address to ensure continuity in data forwarding.
Option e) The standby router will immediately take over if the active router fails.
- True.
- Detail: One of the key features of HSRP is its ability to provide immediate failover. If the active router fails, the standby router will take over as the active router without significant delay. This process involves pre-configured timers and priorities, ensuring minimal disruption in service. HSRP timers (hello and hold timers) determine how quickly the failover happens, with typical configurations allowing for very fast transitions.
Summary:
HSRP is a protocol developed by Cisco to ensure high availability and reliability by providing a mechanism for routers to share a virtual IP address. The key points are that HSRP is proprietary to Cisco, allows multiple routers to share a virtual IP address, uses priorities to determine the active router, and provides immediate failover capabilities.
The correct answers are a) HSRP allows multiple routers to share a virtual IP address and b) The router with the highest priority becomes the active router.
Incorrect options:
- d) HSRP allows routers to dynamically share their MAC addresses: This is incorrect because HSRP uses a static virtual MAC address associated with the virtual IP address.
- e) The standby router will immediately take over if the active router fails: While this is true about HSRP, the question specifies to choose only two correct options, and this aspect is already covered in the correct explanation.
By understanding these details, network administrators can effectively implement HSRP to enhance network reliability and ensure continuous availability of critical network services.