Section 1: Bridging and Switching (16 Points)

Section 1.1: Frame Relay Configuration (6 Points)

• Configure the Frame Relay portion of the network as shown in Figure 2-11 and ensure that DLCIs 110 and 104 between R1 and R6 are not used.

The question clearly states that DLCIs 110 and 104 are not to be used; you must, therefore, disable inverse-arp on the routers. It is good practice to ensure that all routers do not rely on inverse-arp so if you have configured no frame-relay inverse-arp under routers R1, R4, and R6 serial interfaces, you have scored 1 point.

If you experience difficulties and can not clear any dynamic map entries, reload your routers to remove these, a drastic measure but every point counts.

• Use point-to-point subinterfaces with a number equal to that of 10 + the listed DLCIs.

You will need to configure your Frame Relay interfaces as follows: R1- interface Serial0/1.111 point-to-point, R4 - interface Serial0/0.110 point-to-point and interface Serial0/0.112 point-to-point, and finally R6 - interface Serial5/0.113 point-to-point. If you have configured these items correctly, you have scored 1 point.

• Ensure that the Frame Relay subinterfaces contain purely Layer 2 information, configure virtual Layer 3 addresses elsewhere for the Frame Relay connectivity, and make this connectivity as secure as possible. This configuration does not require any form of bridging.

Usually, you would keep your Layer 3 information under the subinterface, but it can be configured in another place. The clues to the question are in keeping it at Layer 2, making it secure, and putting the Layer 3 elsewhere on a virtual interface. The only way to achieve this is by using PPP. Frame Relay is capable of running PPP but it requires the dlci statement to point to a virtual template, which, by default, is a PPP-encapsulated virtual interface. Once created, the virtual template can then contain the Layer 3 address and CHAP statement required to make the PPP connection secure. You will also need a username and password as with ISDN CHAP. If you have configured these items correctly as in Example 2-1 through Example 2-3, you have scored 3 points.

Example 2-1. R1 PPP Frame Relay Solution Configuration

 username R4 password 0 cisco ! interface Serial0/1  no ip address  encapsulation frame-relay  no frame-relay inverse-arp ! interface Serial0/1.111 point-to-point  frame-relay interface-dlci 101 ppp Virtual-Template1 ! interface Virtual-Template1 ip address 10.100.100.1 255.255.255.240  ppp authentication chap ! 

Example 2-2. R4 PPP Frame Relay Solution Configuration

 username R1 password 0 cisco username R6 password 0 cisco ! interface Serial0/0  no ip address  encapsulation frame-relay  no frame-relay inverse-arp ! interface Serial0/0.110 point-to-point  frame-relay interface-dlci 100 ppp Virtual-Template1 ! interface Serial0/0.112 point-to-point  frame-relay interface-dlci 102 ppp Virtual-Template2 ! ! interface Virtual-Template1  ip address 10.100.100.3 255.255.255.240  ppp authentication chap ! interface Virtual-Template2 ip address 10.100.101.1 255.255.255.240  ppp authentication chap ! 

Example 2-3. R6 PPP Frame Relay Solution Configuration

 username R4 password 0 cisco ! interface Serial5/0  no ip address  encapsulation frame-relay  no frame-relay inverse-arp ! interface Serial5/0.113 point-to-point  frame-relay interface-dlci 103 ppp Virtual-Template1 ! interface Virtual-Template1  ip address 10.100.101.2 255.255.255.240  ppp authentication chap 

• For IGP metric calculation, PVC 103-102 has a CIR of 512 kbps and PVC 101-100 has a CIR of 256 kbps. Use these figures appropriately as an IGP reference for the maximum capacity of the links.

Simply configure bandwidth statements under your virtual-template interfaces, R1- bandwidth 256, R4 - bandwidth 256 (interface virtual-template 1) and bandwidth 512 (interface virtual-template 2), and R6 - bandwidth 512. If you have configured this correctly, you have scored 1 point.

Section 1.2: 3550 LAN Switch Configuration (9 Points)

• Configure VLAN numbers, VLAN names, and port assignment as per the topology diagram.

The switch in this instance is isolated as in Chapter 1, but you can still use the default mode of VTP Server. From the VLAN database, add the required VLANs and name them accordingly. You should note that you cannot change the VLAN name of VLAN1. You must ensure that the port speed and duplex is fixed to 100 Mbps and full duplex if your routers support this; leaving your ports in auto mode could cause connectivity problems. If you have configured these items correctly as in Example 2-4, you have scored 2 points.

Example 2-4. 3550 Switch1 Initial Configuration

 Switch1#vlan database Switch1(vlan)#vlan 2 name VLAN2 VLAN 2 modified:     Name: VLAN2 Switch1(vlan)#vlan 3 name VLAN3 VLAN 3 modified:     Name: VLAN3 Switch1(vlan)#vlan 4 name VLAN4 VLAN 4 modified:     Name: VLAN4 Switch1(vlan)#vlan 5 name VLAN5 VLAN 5 modified:     Name: VLAN5 Switch1(vlan)#exit APPLY completed. Exiting.... interface FastEthernet0/1  switchport access vlan 2  switchport mode access  no ip address  duplex full  speed 100 ! interface FastEthernet0/2  switchport mode access  no ip address  duplex full  speed 100 ! interface FastEthernet0/3  switchport mode access  no ip address  duplex full  speed 100 ! interface FastEthernet0/4  switchport access vlan 3  switchport mode access  no ip address  duplex full  speed 100 ! interface FastEthernet0/5  switchport access vlan 4  switchport mode access  no ip address  duplex full  speed 100 ! interface FastEthernet0/6  switchport access vlan 2  switchport mode access  no ip address  duplex full  speed 100 ! interface FastEthernet0/7  switchport access vlan 5  switchport mode access  no ip address  duplex full  speed 100 ! interface FastEthernet0/8  switchport access vlan 2  switchport mode access  no ip address  duplex full  speed 100 ! interface FastEthernet0/9  switchport access vlan 5  switchport mode access  no ip address  duplex full  speed 100 

NOTE

The VLAN configuration is completed under Vlan database.

• Your customer has decided to test Voice over IP (VoIP) and is trialing Cisco 7960 and 7905 IP phones. The customer wants to take advantage of the auxiliary VLAN feature where possible. The 7960 is to be installed on port 0/16 and the 7905 on port 0/17. Use a separate VLAN for the voice of VLAN50 and assume that the customer will also require data access to VLAN2 for this trial; configure your switch appropriately.

First of all, you should be asking are the two Cisco phones identical, and why does it say "take advantage of the auxiliary VLAN feature where possible"? In fact, the phones are very different indeed. The 7960 has the capability to trunk to the 3550. Because it has an onboard 3 port switch, it can separate the voice and data traffic appropriately using the Auxillary VLAN feature and direct data traffic on a separate VLAN to the user port on the phone. The 7905 is a low-end IP phone, which is only 10BASE-T; it simply connects into the switch as a dedicated device and will require insertion manually into VLAN50. It is not typical to be asked product-specific information in the lab but it could happen. The question provides some big clues, so if you are not familiar with the technology, use your CD or online connection (if provided with one). It will save you valuable time and ensure you score the points you need. Example 2-5 shows the 7960 phone configuration for port 0/16. Ensure that you configure the port as a trunk using dot1q encapsulation and that the native VLAN is 2. The switchport voice vlan 50 command sets the Auxillary VLAN for voice communication to and from the 7960.

Example 2-5. 3550 Configuration for the 7960 IP Phone

 vlan 50  name VOICE-VLAN ! interface FastEthernet0/16  switchport access vlan 2  switchport trunk encapsulation dot1q  switchport trunk native vlan 2  switchport mode trunk  switchport voice vlan 50  no ip address  duplex full  speed 100  spanning-tree portfast 

The 7905 phone configuration for port 0/17. You should simply configure the port for access to VLAN50 and ensure the speed is set to 10Mbs as this is a 10BASE-T device. If you have configured these items correctly as in Example 2-5 and Example 2-6, you have scored 4 points.

Example 2-6. 3550 Configuration for the 7905 IP Phone

 interface FastEthernet0/17  switchport access vlan 50  no ip address  duplex half  speed 10 

• A server running Cisco CallManager and the associated IP requirements will also be installed with the IP phones and located in VLAN1; it will be reachable via the address of 172. 16.0.10. You have been allocated the network 10.70.70.0/24 for the voice VLAN. You are not required to advertise the voice VLAN network but ensure you have configured your switch sufficiently so that if connected, the IP phones within this VLAN would be able to load their configuration files from CallManager.

You should be aware that the majority of Cisco IP phones actually use DHCP to gain an IP address and their configuration files via TFTP from CallManager. From the information supplied, you will just need to configure an IP address and a helper address on VLAN50 in the switch, which will forward the DHCP requests to CallManager.

The specific IP address on VLAN50 of the switch can be any address within the range of 10.70.70.1 to 10.70.70.254/24. This information is required so when Call Manager receives the DHCP request from an IP phone, it can assign an address from the correct subnet. As instructed in the question, you will not be required to advertise network 10.70.70.0/24 as this network is purely required for the hypothetical DHCP operation to function correctly within CallManager.

If you have configured this correctly as shown in Example 2-7, you have scored 1 point.

Example 2-7. 3550 Configuration for CallManager Readiness

 interface Vlan50  ip address 10.70.70.1 255.255.255.0  ip helper-address 172.16.0.10 

• The customer also has a requirement to trial a standard OEM IP 10BASE-T telephone alongside the Cisco IP phones on port 0/18; configure your switch appropriately.

This question should give you a clue in regard to the 7960 and 7905 IP phones earlier. Configure port 0/18 similar to the configuration for the 7905 to provide access to VLAN50 with the speed set at 10Mbs. If you have configured this correctly, as shown in Example 2-8, you have scored 1 point.

Example 2-8. 3550 Configuration for Port 0/16 OEM IP Phone

 interface FastEthernet0/18  switchport access vlan 50  no ip address  duplex half  speed 10 

• Ensure the switch is reachable via the IP address of 10.80.80.8/24.

You will need to configure an ip default-gateway 10.80.80.1 onto the 3550; this could also point to 10.80.80.2. If you have configured this correctly, you have scored 1 point.

Section 1.3: ATM Configuration (1 Point)

• Configure the ATM PVCs as shown in Figure 2-12. Do not use subinterfaces and use the new format PVC vpi/vci when configuring the PVCs. Assume aal5snap; do not use the commands protocol ip destination address or broadcast under the PVC configuration mode.

This is a straightforward configuration that relies on inverse ARP to function. The ATM configuration should be performed under the physical interfaces and because broadcasts will not be sent, you will need to adjust the behavior of OSPF later in the lab. The question forces you into making the ATM into an OSPF Non Broadcast Multiple Access (NBMA) network. If you have configured this correctly as shown in Example 2-9 and Example 2-10, you have scored 1 point.

Examples 2-9 and 2-10 also show the dynamic ATM maps created using inverse ARP and a ping test across the ATM for both R5 and R6.

Example 2-9. R5 ATM Configuration: ATM Map and Ping Test

 interface ATM3/0  ip address 10.99.99.2 255.255.255.248  pvc 0/99   encapsulation aal5snap R5#sh atm map Map list ATM3/0_ATM_INARP : DYNAMIC ip 10.99.99.1 maps to VC 1, VPI 0, VCI 99, ATM3/0 R5#ping 10.99.99.1 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 10.99.99.1, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/3/4 ms 

Example 2-10. R6 ATM Configuration: ATM Map and Ping Test

 interface ATM1/0  ip address 10.99.99.1 255.255.255.248  pvc 0/99   encapsulation aal5snap R6#sh atm map Map list ATM1/0_ATM_INARP : DYNAMIC ip 10.99.99.2 maps to VC 1, VPI 0, VCI 99, ATM1/0 R6#ping 10.99.99.2 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 10.99.99.2, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms