Topic 1, Layer 2 Technologies

QUESTION NO: 81

Which statement about the use of PAgP link aggregation on a Cisco switch that is running Cisco IOS Software is true?

A. PAgP modes are off, auto, desirable, and on. Only the combinations auto-desirable, desirabledesirable, and on-on allow the formation of a channel.
B. PAgP modes are active, desirable, and on. Only the combinations active-desirable, desirabledesirable, and on-on allow the formation of a channel.
C. PAgP modes are active, desirable, and on. Only the combinations active-active, desirabledesirable, and on-on allow the formation of a channel.
D. PAgP modes are off, active, desirable, and on. Only the combinations auto-auto, desirabledesirable, and on-on allow the formation of a channel.

 

 

Answer: A
Explanation:

PAgP modes are off, auto, desirable, and on. Only the combinations auto-desirable, desirabledesirable, and on-on will allow a channel to be formed.
The PAgP modes are explained below.
Only the combinations of auto-desirable, desirable-desirable, and on-on will allow a channel to be formed. If a device on one side of the channel does not support PAgP, such as a router, the device on the other side must have PAgP set to on.

 

 

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QUESTION NO: 82

Refer to the exhibit.

Which EtherChannel negotiation protocol is configured on the interface f0/13 – f0/15?

A. Link Combination Control Protocol
B. Port Aggregation Protocol
C. Port Combination Protocol

D. Link Aggregation Control Protocol

 

 

Answer: B
Explanation:

PAgP modes are off, auto, desirable, and on. Only the combinations auto-desirable, desirabledesirable, and on-on will allow a channel to be formed.

The Link Aggregate Control Protocol (LACP) trunking supports four modes of operation: In this example, we see that fa 0/13, fa0/14, and fa0/15 are all in Port Channel 12, which is operating in desirable mode, which is only a PAgP mode.

 

 

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QUESTION NO: 83

Refer to the exhibit.

 

Users of PC-1 experience slow connection when a webpage is requested from the server. To increase bandwidth, the network engineer configured an EtherChannel on interfaces Fa1/0 and Fa0/1 of the server farm switch, as shown here:

 

Server_Switch#sh etherchannel load-balance
EtherChannel Load-Balancing Operational State (src-mac):
Non-IP: Source MAC address
IPv4: Source MAC address
IPv6: Source IP address
Server_Switch#

 

However, traffic is still slow. Which action can the engineer take to resolve this issue?

A. Disable EtherChannel load balancing.
B. Upgrade the switch IOS to IP services image.
C. Change the load-balance method to dst-mac.
D. Contact Cisco TAC to report a bug on the switch.

 

 

Answer: C

Explanation:

Since this traffic is coming from PC-1, the source MAC address will always be that of PC-1, and since the load balancing method is source MAC, traffic will only be using one of the port channel links. The load balancing method should be changed to destination MAC, since the web server has two NICs traffic will be load balanced across both MAC addresses.

 

 

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QUESTION NO: 84

A network engineer changed the port speed and duplex setting of an existing EtherChannel bundle that uses the PAgP protocol. Which statement describes what happens to all ports in the bundle?

A. PAgP changes the port speed and duplex for all ports in the bundle.
B. PAgP drops the ports that do not match the configuration.
C. PAgP does not change the port speed and duplex for all ports in the bundle until the switch is rebooted.
D. PAgP changes the port speed but not the duplex for all ports in the bundle.

 

Answer: A
Explanation:

PAgP aids in the automatic creation of EtherChannel links. PAgP packets are sent between EtherChannel-capable ports in order to negotiate the formation of a channel. Some restrictions are deliberately introduced into PAgP. The restrictions are:

• PAgP does not form a bundle on ports that are configured for dynamic VLANs. PAgP requires that all ports in the channel belong to the same VLAN or are configured as trunk ports. When a bundle already exists and a VLAN of a port is modified, all ports in the bundle are modified to match that VLAN.

• PAgP does not group ports that operate at different speeds or port duplex. If speed and duplex change when a bundle exists, PAgP changes the port speed and duplex for all ports in the bundle.

• PAgP modes are off, auto, desirable, and on. Only the combinations auto-desirable, desirabledesirable, and on-on allow the formation of a channel. The device on the other side must have PAgP set to on if a device on one side of the channel does not support PAgP, such as a router.

 

 

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QUESTION NO: 85

Which statement about using EtherChannel on Cisco IOS switches is true?

A. A switch can support up to eight compatibly configured Ethernet interfaces in an EtherChannel. The EtherChannel provides full-duplex bandwidth up to 800 Mbps only for Fast EtherChannel or 8 Gbps only for Gigabit EtherChannel.
B. A switch can support up to 10 compatibly configured Ethernet interfaces in an EtherChannel. The EtherChannel provides full-duplex bandwidth up to 1000 Mbps only for Fast EtherChannel or 8 Gbps only for Gigabit EtherChannel.
C. A switch can support up to eight compatibly configured Ethernet interfaces in an EtherChannel. The EtherChannel provides full-duplex bandwidth up to 800 Mbps only for Fast EtherChannel or 16 Gbps only for Gigabit EtherChannel.
D. A switch can support up to 10 compatibly configured Ethernet interfaces in an EtherChannel. The EtherChannel provides full-duplex bandwidth up to 1000 Mbps only for Fast EtherChannel or 10 Gbps only for Gigabit EtherChannel.

 

 

Answer: A
Explanation:

An EtherChannel consists of individual Fast Ethernet or Gigabit Ethernet links bundled into a single logical link. The EtherChannel provides full-duplex bandwidth up to 800 Mbps (Fast EtherChannel) or 8 Gbps (Gigabit EtherChannel) between your switch and another switch or host. Each EtherChannel can consist of up to eight compatibly configured Ethernet interfaces. All interfaces in each EtherChannel must be the same speed, and all must be configured as either Layer 2 or Layer 3 interfaces.

 

 

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QUESTION NO: 86

Refer to the exhibit.

Which statement about switch S1 is true?

A. Physical port Fa0/13, Fa0/14, and Fa0/15 successfully formed a Layer 2 port-channel interface using an open standard protocol.
B. Logical port Fa0/13, Fa0/14, and Fa0/15 successfully formed a Layer 2 physical port-channel interface using a Cisco proprietary protocol.
C. Physical port Fa0/13, Fa0/14, and Fa0/15 successfully formed a Layer 3 port-channel interface using a Cisco proprietary protocol.
D. Logical port Fa0/13, Fa0/14, and Fa0/15 successfully formed a Layer 3 physical port-channel interface using an open standard protocol.

 

Answer: A
Explanation:

These three ports show that they are in Port Channel 1, and the (SU) means they are in use and operating at layer 2. The protocol used for this port channel shows as LACP, which is a standards based protocol, as opposed to PAgP, which is Cisco proprietary.

 

 

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QUESTION NO: 87

What happens on a Cisco switch that runs Cisco IOS when an RSTP-configured switch receives 802.1d BPDU?

A. 802.1d does not understand RSTP BPDUs because they are different versions, but when a RSTP switch receives an 802.1d BPDU, it responds with an802.1d BPDU and eventually the two switches run 802.1d to communicate.
B. 802.1d understands RSTP BPDUs because they are the same version, but when a RSTPswitch receives a 802.1d BPDU, it responds with a 802.1d BPDU and eventually the two switches run 802.1d to communicate.
C. 802.1d does not understand RSTP BPDUs because they are different versions, but when a RSTP switch receives a 802.1d BPDU, it does not respond with a 802.1d BPDU.
D. 802.1d understands RSTP BPDUs because they are the same version, but when a RSTP switch receives a 802.1d BPDU, it does not respond with a 802.1d BPDU and eventually the two switches run 802.1d to communicate.

 

Answer: A
Explanation:

For backward compatibility with 802.1D switches, RSTP selectively sends 802.1D configuration
BPDUs and TCN BPDUs on a per-port basis.
When a port is initialized, the migrate-delay timer is started (specifies the minimum time during which RSTP BPDUs are sent), and RSTP BPDUs are sent. While this timer is active, the switch processes all BPDUs received on that port and ignores the protocol type.
If the switch receives an 802.1D BPDU after the port migration-delay timer has expired, it assumes that it is connected to an 802.1D switch and starts using only 802.1D BPDUs. However, if the RSTP switch is using 802.1D BPDUs on a port and receives an RSTP BPDU after the timer has expired, it restarts the timer and starts using RSTP BPDUs on that port.

 

 

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QUESTION NO: 88

When two MST instances (MST 1 and MST 2) are created on a switch, what is the total number of spanning-tree instances running on the switch?

A. 1
B. 2
C. 3
D. 4

 

 

Answer: C
Explanation:

Unlike other spanning tree protocols, in which all the spanning tree instances are independent, MST establishes and maintains IST, CIST, and CST spanning trees:
• An IST is the spanning tree that runs in an MST region.
Within each MST region, MST maintains multiple spanning tree instances. Instance 0 is a special instance for a region, known as the IST. All other MST instances are numbered from 1 to 4094.In the case for this question, there will be the 2 defined MST instances, and the special 0 instance, for a total of 3 instances.
The IST is the only spanning tree instance that sends and receives BPDUs. All of the other spanning tree instance information is contained in MSTP records (M-records), which are encapsulated within MST BPDUs. Because the MST BPDU carries information for all instances, the number of BPDUs that need to be processed to support multiple spanning tree instances is significantly reduced.
All MST instances within the same region share the same protocol timers, but each MST instance has its own topology parameters, such as root bridge ID, root path cost, and so forth. By default, all VLANs are assigned to the IST.
An MST instance is local to the region; for example, MST instance 1 in region A is independent of MST instance 1 in region B, even if regions A and B are interconnected.
• A CIST is a collection of the ISTs in each MST region.
• The CST interconnects the MST regions and single spanning trees.

 

 

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QUESTION NO: 89

Refer to the exhibit.

f1/0 and f1/1 have the same end-to-end path cost to the designated bridge. Which action is needed to modify the Layer 2 spanning-tree network so that traffic for PC1 VLAN from switch SW3 uses switchport f1/1 as a primary port?

 

A. Modify the spanning-tree port-priority on SW1 f1/1 to 0 and f1/0 to 16.
B. Modify the spanning-tree port-priority on SW1 f1/1 to 16 and f1/0 to 0.
C. Modify the spanning-tree port-priority on SW2 f1/1 to 0 and f1/0 to 16.
D. Modify the spanning-tree port-priority on SW2 f1/1 to 16 and f1/0 to 0.

Answer: C
Explanation:

If a loop occurs, STP considers port priority when selecting a LAN port to put into the forwarding state. You can assign higher priority values to LAN ports that you want STP to select first and lower priority values to LAN ports that you want STP to select last. If all LAN ports have the same priority value, STP puts the LAN port with the lowest LAN port number in the forwarding state and blocks other LAN ports. The possible priority range is 0 through 240 (default 128), configurable in increments of 16. A lower path cost represents higher-speed transmission and is preferred.

 

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QUESTION NO: 90

Refer to the exhibit.

Why would the switch be considered as a root bridge?

A. The bridge priority is 1 and all ports are forwarding.
B. The switch priority for VLAN 1 and the macro specifies "This Bridge is the root".
C. The bridge priority is 128.19 and all ports are forwarding.
D. The switch priority value is zero, it has the lowest priority value for VLAN 1.

 

 

Answer: D
Explanation:

For priority, the range is 0 to 61440 in increments of 4096; the default is 32768. The lower the number, the more likely the switch will be chosen as the root switch.

 

 

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QUESTION NO: 91

Refer to the exhibit.

All ports are members of VLAN 10. Considering the default cost of upstream bridges to the root bridge is equal, which option will be the new root port for VLAN 10?

 

A. interface f0/13
B. interface f0/14
C. interface f0/15
D. interface f0/21

 

 

Answer: D
Explanation:

Each (non-Root) bridge has exactly one Root Port, which represents the best path to the Root Bridge. In this case, fa0/21 has the lowest cost, so it will be the root port.

 

 

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QUESTION NO: 92

A network engineer is trying to deploy a PC on a network. The engineer observes that when the PC is connected to the network, it takes 30 to 60 seconds for the PC to see any activity on the network interface card. Which Layer 2 enhancement can be used to eliminate this delay?

A. Configure port duplex and speed to auto negotiation.
B. Configure port to duplex full and speed 1000.
C. Configure spanning-tree portfast.
D. Configure no switchport.

 

 

Answer: C
Explanation:

When first powered on, each port goes through 4 states to ensure that there are no physical loops in the layer 2 broadcast domain. These steps are outlined as follows. With the initial version of spanning tree, this process could take from 30-60 seconds.
1. Blocking - A port that would cause a switching loop, no user data is sent or received but it may go into forwarding mode if the other links in use were to fail and the spanning tree algorithm determines the port may transition to the forwarding state. BPDU data is still received in blocking state.
2. Listening - The switch processes BPDUs and awaits possible new information that would cause it to return to the blocking state.
3. Learning - While the port does not yet forward frames (packets) it does learn source addresses from frames received and adds them to the filtering database (switching database)
4 .Forwarding - A port receiving and sending data, normal operation. STP still monitors incoming BPDUs that would indicate it should return to the blocking state to prevent a loop. STP PortFast causes a Layer 2 LAN interface configured as an access port to enter the forwarding state immediately, bypassing the listening and learning states.

 

 

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QUESTION NO: 93

A network engineer configured an Ethernet switch using these commands.

Switchone(config) # Spanning-tree portfast bpdufilter default

Which statement about the spanning-tree portfast feature on the switch is true?
A. If an interface is enabled for portfast receives BDPU, the port goes through the spanning-tree listening, learning, and forwarding states.
B. If an interface is enabled for portfast receives BDPU, the port does not go through the spanning-tree listening, learning, and forwarding states.
C. If an interface is enabled for portfast receives BDPU, the port is shut down immediately.
D. If an interface is enabled for portfast receives BDPU, the port goes into the spanning-tree inconsistent state.

 

 

Answer: A

Explanation:

STP PortFast causes a Layer 2 LAN interface configured as an access port to enter the forwarding state immediately, bypassing the listening and learning states. However, the “Spanning-tree portfast bpdufilter default” command specifies that if a BPDU is received on that port, then the default action of STPof listening, learning, and forwarding states should be used.

 

 

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QUESTION NO: 94

Which statement describes what happens when a port configured with root guard receives a superior BPDU?

A. The port goes into errdisabled state and stops forwarding traffic.
B. The port goes into BPDU-inconsistent state and stops forwarding traffic.
C. The port goes into loop-inconsistent state and stops forwarding traffic.
D. The port goes into root-inconsistent state and stops forwarding traffic.

 

Answer: D
Explanation:

The root guard ensures that the port on which root guard is enabled is the designated port. Normally, root bridge ports are all designated ports, unless two or more ports of the root bridge are connected together. If the bridge receives superior STP Bridge Protocol Data Units (BPDUs) on a root guard-enabled port, root guard moves this port to a root-inconsistent STP state. This rootinconsistent state is effectively equal to a listening state. No traffic is forwarded across this port. In this way, the root guard enforces the position of the root bridge.

 

 

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QUESTION NO: 95

Which statement about restrictions for multichassis LACP is true?

A. It is available only on a Cisco Catalyst 6500 Series chassis.
B. It does not support 1Gb links.
C. Converting a port channel to mLACP can cause a service disruption.
D. It is not available in VSS.

 

 

Answer: C
Explanation:

When configuring mLACP for Server Access, follow these guidelines and restrictions:
• PFC3A mode does not support the mLACP for server access feature.
• VSS mode does not support the mLACP for server access feature.
• No more than 100 VLANs can be active on a switch configured as a PoA.
• mLACP does not support half-duplex links.
• mLACP does not support multiple neighbors.
• Converting a port channel to mLACP can cause a service disruption.
• The DHD system priority must be lower (higher numerically) than the PoA system priority.

 

 

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QUESTION NO: 96

What is the maximum number of 10 Gigabit Ethernet connections that can be utilized in an EtherChannel for the virtual switch link?
A. 4
B. 6
C. 8
D. 12

 

Answer: C
Explanation:

The VSS is made up of the following:
• Virtual switch members: Cisco Catalyst 6500 Series Switches (up to two switches with initial release) deployed with the Virtual Switching Supervisor 720 10GE
• Virtual switch link (VSL): 10 Gigabit Ethernet connections (up to eight using EtherChannel) between the virtual switch members.

 

 

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QUESTION NO: 97

Which statement describes what happens if all VSL connections between the virtual switch members are lost?

A. Both virtual switch members cease to forward traffic.
B. The VSS transitions to the dual active recovery mode, and both virtual switch members continue to forward traffic independently.
C. The virtual switch members reload.
D. The VSS transitions to the dual active recovery mode, and only the new active virtual switch continues to forward traffic.

 

Answer: D
Explanation:

Q. What happens if all VSL connections between the virtual switch members are lost?
A. VSLs can be configured with up to eight links between the two switches across any combination of line cards or supervisor ports to provide a high level of redundancy. If for some rare reason all VSL connections are lost between the virtual switch members leaving both the virtual switch members up, the VSS will transition to the dual active recovery mode.
The dual active state is detected rapidly (subsecond) by any of the following three methods:
• Enhancement to PAgP used in MEC with connecting Cisco switches
• L3 Bidirectional Forwarding Detection (BFD) configuration on a directly connected link (besides VSL) between virtual switch members or through an L2 link through an access layer switch
• L2 Fast-Hello Dual-Active Detection configuration on a directly connected link (besides VSL) between virtual switch members (supported with 12.2(33)SXI)
In the dual active recovery mode, all interfaces except the VSL interfaces are in an operationally shut down state in the formerly active virtual switch member. The new active virtual switch continues to forward traffic on all links.

 

 

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QUESTION NO: 98

Which statement describes what happens when a switch enters dual active recovery mode?

A. The switch shuts down and waits for the VSL link to be restored before sending traffic.
B. All interfaces are shut down in the formerly active virtual switch member, but the new active virtual switch forwards traffic on all links.
C. The switch continues to forward traffic out all links and enables spanning tree on VSL link and all other links to prevent loops.
D. The VSS detects which system was last in active state and shuts down the other switch.

 

 

Answer: B
Explanation:

In the dual active recovery mode, all interfaces except the VSL interfaces are in an operationally shut down state in the formerly active virtual switch member. The new active virtual switch continues to forward traffic on all links.

 

 

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QUESTION NO: 99 Labrator

You work for SWITCH.com. They have just added a new switch (SwitchB) to the existing network as shown in the topology diagram.

RouterA is currently configured correctly and is providing the routing function for devices on SwitchA and SwitchB. SwitchA is currently configured correctly, but will need to be modified to support the addition of SwitchB. SwitchB has a minimal configuration. You have been tasked with competing the needed configuring of SwitchA and SwitchB. SwitchA and SwitchB use Cisco as the enable password.

Configuration Requirements for SwitchA
The VTP and STP configuration modes on SwitchA should not be modified.
• SwitchA needs to be the root switch for vlans 11, 12, 13, 21, 22 and 23. All other vlans should be left are their default values.

 

Configuration Requirements for SwitchB
• Vlan 21
Name: Marketing
will support two servers attached to fa0/9 and fa0/10
• Vlan 22
Name: Sales
will support two servers attached to fa0/13 and fa0/14
• Vlan 23
o Name: Engineering
o will support two servers attached to fa0/15 and fa0/16
• Access ports that connect to server should transition immediately to forwarding state upon detecting the connection of a device.
• SwitchB VTP mode needs to be the same as SwitchA.
• SwitchB must operate in the same spanning tree mode as SwitchA
• No routing is to be configured on SwitchB
• Only the SVI vlan 1 is to be configured and it is to use address 192.168.1.11/24

 

Inter-switch Connectivity Configuration Requirements
• For operational and security reasons trunking should be unconditional and Vlans 1, 21, 22 and 23 should tagged when traversing the trunk link.
• The two trunks between SwitchA and SwitchB need to be configured in a mode that allows for the maximum use of their bandwidth for all vlans. This mode should be done with a nonproprietary protocol, with SwitchA controlling activation.
• Propagation of unnecessary broadcasts should be limited using manual pruning on this trunk link.

Answer:

Here are steps:
hostname SWITCH_B
!
!
vlan 21
name Marketing
vlan 22
name Sales
vlan 23
name Engineering
!
!
interface FastEthernet0/3
switchport trunk allowed vlan 1,21-23
channel-protocol lacp
channel-group 1 mode passive
switchport mode trunk
!
interface FastEthernet0/4
switchport trunk allowed vlan 1,21-23
channel-protocol lacp
channel-group 1 mode passive
switchport mode trunk
!
interface FastEthernet0/9
switchport access vlan 21
switchport mode access
spanning-tree portfast

!
interface FastEthernet0/10
switchport access vlan 21
switchport mode access
spanning-tree portfast
!
interface FastEthernet0/13
switchport access vlan 22
switchport mode access
spanning-tree portfast
!
!
interface FastEthernet0/14
switchport access vlan 22
switchport mode access
spanning-tree portfast
!
interface FastEthernet0/15
switchport access vlan 23
switchport mode access
spanning-tree portfast
!
interface FastEthernet0/16
switchport access vlan 23
switchport mode access
spanning-tree portfast
!
!
interface GigabitEthernet1/1
!
interface GigabitEthernet1/2
!
interface Port-channel 1
switchport mode trunk
switchport trunk encapsulation dot1q
spanning-tree allowed vlans 1,21-23
!
interface Vlan1
ip address 192.168.1.11 255.255.255.0
!
end

 

SWITCH_B(config)#
hostname SWITCH_A
!
panning-tree vlan 11 root primary
spanning-tree vlan 12 root primary
spanning-tree vlan 13 root primary
spanning-tree vlan 21 root primary
spanning-tree vlan 22 root primary
spanning-tree vlan 23 root primary
!
interface FastEthernet0/3
switchport trunk allowed vlan 1,21-23
channel-protocol lacp
channel-group 1 mode active
switchport mode trunk
!
interface FastEthernet0/4
switchport trunk allowed vlan 1,21-23
channel-protocol lacp
channel-group 1 mode active
switchport mode trunk
!
interface FastEthernet0/21
switchport access vlan 21
switchport mode access
!
interface FastEthernet0/22
switchport access vlan 22
switchport mode access
!
interface FastEthernet0/23
switchport access vlan 23
switchport mode access
!
interface GigabitEthernet1/1
!
interface GigabitEthernet1/2
!
interface Port-channel 1
!
interface Vlan1

no ip address
shutdown
!
ip default-gateway 192.168.1.1
!
!
End

 

 

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QUESTION NO: 100

You have been tasked with configuring multilayer SwitchC, which has a partial configuration and has been attached to RouterC as shown in the topology diagram.
You need to configure SwitchC so that Hosts H1 and H2 can successfully ping the server S1. Also SwitchC needs to be able to ping server S1.
Due to administrative restrictions and requirements you should not add/delete vlans or create trunk links. Company policies forbid the use of static or default routing. All routes must be learned via EIGRP 65010 routing protocol.
You do not have access to RouteC. RouterC is correctly configured. No trunking has been configured on RouterC.
Routed interfaces should use the lowest host on a subnet when possible. The following subnets are available to implement this solution:
– 10.10.10.0/24
– 190.200.250.32/27
– 190.200.250.64/27
Hosts H1 and H2 are configured with the correct IP address and default gateway.
SwitchC uses Cisco as the enable password.
Routing must only be enabled for the specific subnets shown in the diagram.
Note: Due to administrative restrictions and requirements you should not add or delete VLANs, changes VLAN port assignments or create trunks. Company policies forbid the use of static or default routing. All routes must be learned via the EIGRP routing protocol.

Answer:

There are two ways to configure interVLAN routing in this case:
+ Use RouterC as a “router on a stick” and SwitchC as a pure Layer2 switch. Trunking must be established between RouterC and SwitchC.
+ Only use SwitchC for interVLAN routing without using RouterC, SwitchC should be configured as a Layer 3 switch (which supports ip routing function as a router). No trunking requires. The question clearly states “No trunking has been configured on RouterC” so RouterC does not contribute to interVLAN routing of hosts H1 & H2 -> SwitchC must be configured as a Layer 3 switch with SVIs for interVLAN routing.
We should check the default gateways on H1 & H2. Click on H1 and H2 and type the “ipconfig” command to get their default gateways.
Answer: \>ipconfig
We will get the default gateways as follows:
Host1:
+ Default gateway: 190.200.250.33
Host2:
+ Default gateway: 190.200.250.65
Now we have enough information to configure SwitchC (notice the EIGRP AS in this case is 650)
Note: VLAN2 and VLAN3 were created and gi0/10, gi0/11 interfaces were configured as access ports so we don’t need to configure them in this sim.
SwitchC# configure terminal
SwitchC(config)# int gi0/1
SwitchC(config-if)#no switchport -> without using this command, the simulator does not let you assign IP address on Gi0/1 interface.
SwitchC(config-if)# ip address 10.10.10.2 255.255.255.0 ->RouterC has used IP 10.10.10.1 so
this is the lowest usable IP address.
SwitchC(config-if)# no shutdown
SwitchC(config-if)# exit
SwitchC(config)# int vlan 2
SwitchC(config-if)# ip address 190.200.250.33 255.255.255.224
SwitchC(config-if)# no shutdown
SwitchC(config-if)# int vlan 3
SwitchC(config-if)# ip address 190.200.250.65 255.255.255.224
SwitchC(config-if)# no shutdown
SwitchC(config-if)#exit
SwitchC(config)# ip routing (Notice: MLS will not work without this command)
SwitchC(config)# router eigrp 65010
SwitchC(config-router)# network 10.10.10.0 0.0.0.255
SwitchC(config-router)# network 190.200.250.32 0.0.0.31
SwitchC(config-router)# network 190.200.250.64 0.0.0.31
NOTE: THE ROUTER IS CORRECTLY CONFIGURED, so you willnot miss within it in the exam, also don’t modify/delete any port just do the above configuration. Also some reports said the “no auto-summary” command can’t be used in the simulator, in fact it is not necessary because the network 190.200.0.0/16 is not used anywhere else in this topology.
In order to complete the lab, you should expect the ping toSERVER to succeed from the MLS, and from the PCs as well.
Also make sure you use the correct EIGRP AS number (in the configuration above it is 650 but it will change when you take the exam) but we are not allowed to access RouterC so the only way to find out the EIGRP AS is to look at the exhibit above. If you use wrong AS number, no neighbor relationship is formed between RouterC and SwitchC.

In fact, we are pretty sure instead of using two commands “network 190.200.250.32 0.0.0.31 and “network 190.200.250.64 0.0.0.31 we can use one simple command “network 190.200.0.0 because it is the nature of distance vector routing protocol like EIGRP: only major networks need to be advertised; even without “no auto-summary” command the network still works correctly. But in the exam the sim is just a flash based simulator so we should use two above commands, just for sure. But after finishing the configuration, we can use “show run” command to verify, only the summarized network 190.200.0.0 is shown.