Cisco (200-301) Exam Questions And Answers page 60

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.
• y.y.y.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.
Objective:
Routing Fundamentals
Sub-Objective:
Configure, verify, and troubleshoot EIGRP for IPv4 (excluding authentication, filtering, manual summarization, redistribution, stub)
Cisco > Support > Cisco IOS Software > Configuring EIGRP > Enabling EIGRP

Both routers have been configured with the ip host command. This command creates a name to IP address mapping, thereby enabling the pinging of the device by address. On R1, the mapping is incorrect and needs to be corrected. Currently it is configured as ip host R1 192.168.5.6. It is currently mapping its own name to the IP address of R2.
To fix the problem, you should remove the incorrect IP address mapping and create the correct mapping for R2, as follows:
R1(config)#no ip host R1
R1(config)# ip host R2 192.168.5.6 255.255.255.252

Once this is done, the ping on R2 will succeed.
The IP address of the S1 interface on R1 does not need to be changed to 192.168.5.9 /30. In fact, if that is done the S1 interface on R1 and the S1 interface in R2 will no longer be in the same network. With a 30-bit mask configured, the network they are currently in extends from 192.168.5.4 - 192.168.5.7. They are currently set to the two usable addresses in that network, 192.168.5.5 and 192.168.5.6.
The hostnames of the two routers do need to be set correctly using the hostname command for the ping to function, but they are correct now and do not need to be changed.
The subnet mask of the S1 interface on R2 does not need to be changed to 255.255.255.0. The mask needs to match that of R1, which is 255.255.255.252.
Objective:
Infrastructure Services
Sub-Objective:
Troubleshoot client connectivity issues involving DNS
References:

VLAN 1 traffic cannot be pruned. Cisco recommends that VLAN 1 be used for management of VLANs.
VTP pruning is a Cisco VTP feature that allows switches to dynamically delete or add VLANs to a trunk for traffic transmission. It creates an efficient switching network by optimal use of available trunk bandwidth.
The options 10, 100, and 1000 are incorrect because these VLAN numbers can be pruned. By default, VLANs 2 to 1000 are eligible for pruning.
Objective:
LAN Switching Fundamentals
Sub-Objective:
Configure, verify, and troubleshoot VLANs (normal/extended range) spanning multiple switches
Cisco Press Home > Articles > Cisco Certification > CCNA > CCNA Self-Study (ICND Exam): Extending Switched Networks with Virtual LANs

You could either configure separate VLANs for each department or configure separate subnets for each department. Either approach has the effect of restricting each department's traffic to its local subnet or VLAN, unless you configure and allow inter-VLAN routing.
VLANs logically divide a switched network into multiple independent broadcast domains. Broadcast traffic within one VLAN will never be sent to hosts in other VLANs. In this respect, VLANs operate exactly as subnets do. The only way for hosts in different VLANs to communicate is through a router or multilayer switch configured to perform inter-VLAN routing between the VLANs.
The VLAN Trunking Protocol (VTP) is used to synchronize VLAN databases across multiple switches, and is not a method for isolating departmental traffic.
Collision domains cannot be used to isolate traffic between departments. Multiple departments cannot share a collision domain when using switches. Every port on a switch is a separate collision domain, which allows the switch to forward more than one frame at a time. This also reduces collisions, since each host is therefore in a separate collision domain. The switch processes data based only on MAC addresses, and has no knowledge of which host is in which IP subnet or department.
Trunk links are used to connect switches to other switches and to routers for the purpose of carrying traffic from multiple VLANs, and are not a method of isolating traffic between different departments.
Objective:
LAN Switching Fundamentals
Sub-Objective:
Configure, verify, and troubleshoot VLANs (normal/extended range) spanning multiple switches
Cisco > Internetwork Design Guide > Designing Switched LAN Internetworks > Benefits of VLANs

From the output we can see there are Designated Router & Backup Designated Router for this OSPF domain so this is a broadcast network (point-to-point and point-to-multipoint networks do not elect DR & BDR).
By default, the timers on a broadcast network (Ethernet, point-to-point and point-to-multipoint) are 10 seconds hello and 40 seconds dead. The timers on a non-broadcast network are 30 seconds hello 120 seconds dead.
From the line Neighbor Count is 3 , we learn there are four OSPF routers in this OSPF domain.