Lab 18: Configuring PVCs on Cisco 7XXX Routers, RFC 2684-Part II

Lab 16: Configuring PPP Authentication, Callback, and Multilink over ISDN

The ABC network consists of the network topology in Figure 7-11. The primary communications link is the Frame Relay circuit, with the ISDN line used only as specified in the requirements. The CEO of this network is set in his ways. He has asked you to design a network for him that meets some specific requirements:

Figure 7-11. Network Topology for This Lab

1. Configure the network using OSPF as the routing protocol, as shown in Figure 7-11.

2. Maintain site-to-site connectivity even after a Frame Relay outage. The ISDN link should be utilized only when there is a physical break in the frame network or when the primary frame link exceeds 50 percent utilization. The ISDN call should wait 10 seconds after the Frame Relay link goes down in case of a brief outage . The call also should get disconnected after 2 minutes upon restoration of the Frame Relay link, or after the load on this link goes back down to 25 percent. Only one PVC is expected to be used on the Frame Relay interfaces.

3. Both ISDN B channels are to be utilized immediately whenever a connection is made.

4. Use authentication, but ensure that the passwords are not encrypted over the ISDN link.

5. Both routers must be capable of initiating ISDN calls.

6. No static routes are to be used.

Figure 7-11 shows the network topology for this lab.

Lab 16 Solution

Example 7-61 shows the complete solution to this lab, followed by a discussion pertaining to it.

Example 7-60 Configurations for Phoenix2, Phoenix, Green Bay, San Diego, and Minneapolis Routers

 Phoenix2#  show running-config  Building configuration... Current configuration: ! version 11.2 no service password-encryption no service udp-small-servers no service tcp-small-servers ! hostname Phoenix2 ! enable password cisco ! ! interface Ethernet0  ip address 170.10.35.2 255.255.255.0 ! interface Ethernet1  no ip address  shutdown ! interface Serial0  no ip address  shutdown  no fair-queue ! interface Serial1  no ip address  shutdown ! router ospf 1  network 170.10.0.0 0.0.255.255 area 1 ! no ip classless ! ! line con 0  exec-timeout 0 0  privilege level 15  logging synchronous line aux 0 line vty 0 4  password cisco  login ! end _______________________________________________________________________ Phoenix#  show running-config  Building configuration... Current configuration: ! version 12.0 service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname Phoenix ! logging buffered 9096 debugging ! ip subnet-zero isdn switch-type basic-dms100 ! ! ! interface Ethernet0  ip address 170.10.35.1 255.255.255.0  no ip directed-broadcast ! interface Serial0  no ip address  no ip directed-broadcast  shutdown ! interface Serial1  description POINT TO POINT LINK TO GREEN BAY  bandwidth 64  ip address 170.10.23.2 255.255.255.252  no ip directed-broadcast  clockrate 125000 ! router ospf 1  network 170.10.0.0 0.0.255.255 area 1 ! no ip classless ! ! ! line con 0  privilege level 15  logging synchronous  transport input none line aux 0 line vty 0 4  login ! end _______________________________________________________________________ Green_Bay#  show running-config  Building configuration... Current configuration: ! version 12.0 service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname Green_Bay ! ! username San_Diego password 0 isdnlab ip subnet-zero isdn switch-type basic-dms100 ! ! ! interface Ethernet0  ip address 170.10.22.1 255.255.255.0  no ip directed-broadcast  no keepalive ! interface Serial0  backup delay 10 120  backup interface BRI0  backup load 50 25  no ip address  no ip directed-broadcast  encapsulation frame-relay  logging event subif-link-status  logging event dlci-status-change  no fair-queue  clockrate 125000 ! interface Serial0.1 point-to-point  ip address 170.10.29.1 255.255.255.252  no ip directed-broadcast  frame-relay interface-dlci 300 ! interface Serial1  description POINT TO POINT LINK TO PHOENIX  bandwidth 64  ip address 170.10.23.1 255.255.255.252  no ip directed-broadcast ! interface BRI0  ip address 170.10.129.1 255.255.255.252  no ip directed-broadcast  encapsulation ppp  dialer map ip 170.10.129.2 name San_Diego broadcast 6129319360  dialer load-threshold 1 either  dialer-group 1  isdn switch-type basic-dms100  isdn spid1 61293199371111  isdn spid2 61293199381111  ppp authentication pap  ppp pap sent-username Green_Bay password 7 141E010F02082B29  ppp multilink ! router ospf 1  network 170.10.22.1 0.0.0.0 area 1  network 170.10.23.1 0.0.0.0 area 1  network 170.10.29.1 0.0.0.0 area 0  network 170.10.129.1 0.0.0.0 area 0 ! no ip classless ! dialer-list 1 protocol ip permit ! ! line con 0  privilege level 15  logging synchronous  transport input none line aux 0 line vty 0 4  login ! end _______________________________________________________________________ San_Diego#  show running-config  Building configuration... Current configuration: ! version 11.2 no service password-encryption no service udp-small-servers no service tcp-small-servers ! hostname San_Diego ! enable password cisco ! username Green_Bay password 0 isdnlab ip subnet-zero no ip domain-lookup isdn switch-type basic-dms100 ! interface Ethernet0  no ip address  no keepalive  media-type 10BaseT ! interface Serial0  backup delay 10 120  backup interface BRI0  backup load 50 25  no ip address  encapsulation frame-relay ! interface Serial0.1 point-to-point  ip address 170.10.29.2 255.255.255.252  frame-relay interface-dlci 200 ! interface Serial1  ip address 170.10.49.2 255.255.255.252  clockrate 125000 ! ! interface BRI0  ip address 170.10.129.2 255.255.255.252  encapsulation ppp  isdn spid1  61293193601111  isdn spid2  61293197761111  dialer map ip 170.10.129.1 name Green_Bay broadcast 6129319937 dialer load-threshold 1 either  dialer-group 1  no fair-queue  ppp authentication pap  ppp pap sent-username San_Diego password 7 09455D0D17091610  ppp multilink ! interface BRI1  no ip address  shutdown ! interface BRI2  no ip address  shutdown ! interface BRI3  no ip address  shutdown ! router ospf 1  network 170.10.0.0 0.0.255.255 area 0 ! ip classless ! dialer-list 1 protocol ip permit ! line con 0  exec-timeout 0 0  privilege level 15  logging synchronous line aux 0 line vty 0 4  exec-timeout 0 0  privilege level 15  logging synchronous  no login ! end _______________________________________________________________________ Minneapolis#  show running-config  Building configuration... Current configuration: ! version 11.2 no service password-encryption no service udp-small-servers no service tcp-small-servers ! hostname Minneapolis ! enable password cisco ! ! interface Ethernet0  ip address 170.10.44.1 255.255.255.0  no keepalive ! interface Serial0  no ip address  shutdown  no fair-queue ! interface Serial1  ip address 170.10.49.1 255.255.255.252 ! router ospf 1  network 170.10.0.0 0.0.255.255 area 0 ! no ip classless ! ! line con 0  privilege level 15  logging synchronous line aux 0 line vty 0 4  privilege level 15  password cisco  no login ! end 

Lab 16 Solution Discussion

We will keep our discussion here to the Green Bay and San Diego routers because the configuration for the other three routers is fairly straightforward.

Because this lab asked that the ISDN link be utilized after a physical break in the ISDN connection, using the backup interface command was the most appropriate solution. In addition, the lab asked you to utilize the ISDN connection if the frame link became congested , so the backup load command also was used. Using PPP multilink and setting the dialer load-threshold to 1 either way satisfied requirement 3. Using PAP authentication completed requirement 4. Finally, both routers used dialer maps in their configurations, satisfying requirement 5. This lab did not specifically ask you to use dialer maps, so you could have just as easily used dialer strings or dialer profiles.