Explanation:
EIGRP does not require a hierarchical physical topology. It uses Diffusing Update Algorithm (DUAL) to provide loop prevention, and it supports Message-Digest Algorithm 5 (MD5) authentication. It can differentiate between internal and external routes, and uses a 32-bit metric.

EIGRP is a classless protocol that allows the use of variable length subnet masks (VLSM) and supports classless interdomain routing (CIDR) for allocation of IP addresses. The following are characteristics of EIGRP:

– Supports large networks due to high scalability
– Provides fast convergence using the Diffusing Update Algorithm (DUAL) Performs equal and unequal load balancing by default
– Supports variable length subnet masks (VLSM) and classless interdomain routing (CIDR)
– Is a hybrid routing protocol (distance-vector protocol) that also provides link-state protocol characteristics Is a classless protocol
– Sends partial route updates only when there are changes, reducing bandwidth usage for routing updates
– Has an administrative distance of 90 for EIGRP internal routes, 170 for EIGRP external routes, and 5 for EIGRP summary routes Is used only with Cisco platforms
– Provides support for IP IPX and AppleTalk protocols Can differentiate between internal and external routes Uses a 32-bit metric

EIGRP can load-balance up to four unequal cost paths. To do so, use the variance n command to instruct the router to include routes with a metric of less than n times the minimum metric route for that destination. The variable n can take a value between 1 and 128. The default is 1, which means equal cost load balancing.

The option stating that EIGRP requires a hierarchical physical topology is incorrect because EIGRP does not require or support a hierarchical routing topology. The option stating that EIGRP uses Bellman-Ford algorithm to provide loop prevention is incorrect. EIGRP uses DUAL to provide loop prevention.

Explanation:
The router eigrp 10 command is used to enable EIGRP on a router. The network 10.0.0.0 and network 192.168.1.0 commands are used to activate EIGRP over the interfaces configured with IP addresses 10.2.2.2 and 192.168.1.1. If we were given the subnet mask for the two interfaces, we could include that in the network command as well.

The following command sequence is used to configure EIGRP on a router:

router(config) # router eigrp [autonomous-system] router (config-router) # network x.x.x.x [wildcard-mask] router (config-router) # network y.y.y.y [wildcard-mask]

The autonomous-system parameter of the router eigrp command specifies the autonomous system number. To ensure that all the routers in a network can communicate with each other, you should specify the same autonomous system number on all the routers.

The parameters of the network command are:

x.x.x.x – This is the major (classful) network number connected to the router.
x.x.x.y – This is the other major (classful) network number connected to the router.

If either the AS numbers do not match between two EIGRP routers or one end is not configured with EIGRP, no EIGRP routes will appear in the routing table of either router, because they will not have formed an EIGRP neighbor relationship. In this situation you will be able ping between the routers, but you will not be able
to ping LANs attached to the other router.

The router eigrp command is incorrect because you need to specify the autonomous system number after the command to enable EIGRP in a network. The router eigrp 10 command includes the autonomous-system parameter.

The network 192.168.1.1 and network 10.2.2.2 commands are incorrect because the command must be in terms of the network or subnet ID of the network in which the interfaces reside. It is not entered in terms of the address of the interfaces.

Explanation:
Response is not a packet type used by EIGRP. The following are the packet types used by EIGRP:

– Hello/Ack: Establish neighbor relationships. The Ack packet is used to provide acknowledgement of a reliable packet.
– Update: Send routing updates.
– Query: Ask neighbors about routing information.
– Reply: Provide response to queries about routing information.
– Requests: Gain specific information from one or more neighbors.