1.1.2 Lab – Troubleshoot IPv4 and IPv6 Addressing Issues (Answers)

1.1.2 Lab – Troubleshoot IPv4 and IPv6 Addressing Issues (Answers)

Instructor Note: Red font color or gray highlights indicate text that appears in the instructor copy only.

Topology

1.1.2 Lab - Troubleshoot IPv4 and IPv6 Addressing Issues (Answers) 2

Addressing Table

Device Interface IPv4 Address/Mask IPv6 Address/Prefix IPv6 Link Local
R1 G0/0/0 10.10.20.1/24 2001:db8:a:b::1/64 fe80::1:1
G0/0/1 10.10.10.1/24 2001:db8:a:a::1/64 fe80::1:2
Lo0 209.165.200.225/29 2001:db8:a:c::1/64 fe80::1:3
R2 G0/0/0 10.10.20.254/24 2001:db8:a:b::1/64 fe80::2:1
D1 VLAN 10 10.10.10.2/24 2001:db8:a:a::2/64 fe80::d1:1
PC1 NIC DHCP SLAAC EUI-64
PC2 NIC DHCP SLAAC EUI-64

Objectives

Troubleshoot network issues related to IPv4 and IPv6 Addressing.

Background / Scenario

In this topology, router R1 provides connectivity to a simulated internet for VLAN 10. R2 serves as a DHCP server. Switch D1 provides connectivity for VLAN 10. You will be loading configurations with intentional errors onto the network. Your tasks are to FIND the error(s), document your findings and the command(s) or method(s) used to fix them. FIX the issue(s) presented here and then test the network to ensure both of the following conditions are met:

1) the complaint received in the ticket is resolved
2) full reachability is restored

Note: The routers used with CCNP hands-on labs are Cisco 4221 with Cisco IOS XE Release 16.9.4 (universalk9 image). The switches used in the labs are Cisco Catalyst 3650 with Cisco IOS XE Release 16.9.4 (universalk9 image). Other routers, switches, and Cisco IOS versions can be used. Depending on the model and Cisco IOS version, the commands available and the output produced might vary from what is shown in the labs. Refer to the Router Interface Summary Table at the end of the lab for the correct interface identifiers.

Note: Make sure that the switches have been erased and have no startup configurations. If you are unsure, contact your instructor.

Instructor Note: Refer to the Instructor Lab Manual for the procedures to initialize and reload devices.

Required Resources

  • 2 Routers (Cisco 4221 with Cisco IOS XE Release 16.9.4 universal image or comparable)
  • 1 Switch (Cisco 3560 with Cisco IOS XE Release 16.9.4 universal image or comparable)
  • 2 PCs (Choice of operating system with terminal emulation program installed)
  • Console cables to configure the Cisco IOS devices via the console ports
  • Ethernet cables as shown in the topology

Instructions

Part 1: Trouble Ticket 1.1.2.1

Scenario:

PC1 is unable to access resources on web server 209.165.200.225.

Use the commands listed below to load the configuration files for this trouble ticket:

Instructor Note: Commands for uploading the configuration are provided at the end of this document.

Device Command
R1 copy flash:/enarsi/1.1.2.1-r1-config.txt run
R2 copy flash:/enarsi/1.1.2.1-r2-config.txt run
D1 copy flash:/enarsi/1.1.2.1-d1-config.txt run

• PC1 and PC2 should be configured for and receive an address from an IPv4 DHCP server.
• Passwords on all devices are cisco12345. If a username is required, use admin.
• When you have fixed the ticket, change the MOTD on EACH DEVICE using the following command:

banner motd # This is $(hostname) FIXED from ticket <ticket number> #

• Then save the configuration by issuing the wri command (on each device).
• Inform your instructor that you are ready for the next ticket.
• After the instructor approves your solution for this ticket, issue the reset.now privileged EXEC command. This script will clear your configurations and reload the devices.

Instructor Notes:

This trouble ticket contains 1 intentional error. The default-router command on the DHCP server is assigning the wrong default-gateway address.

The commands used to fix these errors should be:

R2(config)# ip dhcp pool LAN4_10
R2(config-router)# no default-router 10.10.20.254
R2(config-router)# default-router 10.10.10.1
R2(config-router)# end

Part 2: Trouble Ticket 1.1.2.2

Scenario:

PC1 and PC2 are unable to lease IPv4 addresses from the DHCP server.

Use the commands listed below to load the configuration files for this trouble ticket:

Instructor Note: Commands for creating these files are at the end of this document.

Device Command
R1 copy flash:/enarsi/1.1.2.2-r1-config.txt run
R2 copy flash:/enarsi/1.1.2.2-r2-config.txt run
D1 copy flash:/enarsi/1.1.2.2-d1-config.txt run

• PC1 and PC2 should be configured for and receive an address from an IPv4 DHCP server.
• Passwords on all devices are cisco12345. If a username is required, use admin.
• When you have fixed the ticket, change the MOTD on EACH DEVICE using the following command:

banner motd # This is $(hostname) FIXED from ticket <ticket number> #

• Then save the configuration by issuing the wri command (on each device).
• Inform your instructor that you are ready for the next ticket.
• After the instructor approves your solution for this ticket, issue the reset.now privileged EXEC command. This script will clear your configurations and reload the devices.

Instructor Notes:

This trouble ticket contains 1 intentional error. The ip helper-address command has been configured on the wrong interface on R1.

The commands used to fix these errors should be:

R1(config)# interface g0/0/0
R1(config-if)# no ip helper-address 10.10.20.254
R1(config-if)# exit
R1(config)# interface g0/0/1
R1(config-if)# ip helper-address 10.10.20.254
R1(config-if)# end

Part 3: Trouble Ticket 1.1.2.3

Scenario:

PC1 and PC2 are unable to resolve IPv6 addresses to hostnames. Upon investigation, it appears that they are not receiving DNS server information from the DHCPv6 server.

Use the commands listed below to load the configuration files for this trouble ticket:

Instructor Note: Commands for creating these files are at the end of this document.

Device Command
R1 copy flash:/enarsi/1.1.2.3-r1-config.txt run
R2 copy flash:/enarsi/1.1.2.3-r2-config.txt run
D1 copy flash:/enarsi/1.1.2.3-d1-config.txt run

• PC1 and PC2 should be configured to assign an address via SLAAC.
• Passwords on all devices are cisco12345. If a username is required, use admin.
• When you have fixed the ticket, change the MOTD on EACH DEVICE using the following command:

banner motd # This is $(hostname) FIXED from ticket <ticket number> #

• Then save the configuration by issuing the wri command (on each device).
• Inform your instructor that you are ready for the next ticket.
• After the instructor approves your solution for this ticket, issue the reset.now privileged EXEC command. This script will clear your configurations and reload the devices.

Instructor Notes:

This trouble ticket contains 1 intentional error. The ipv6 nd other-config-flag command is not present in the R1 configuration.

R1(config)# interface g0/0/1
R1(config-if)# ipv6 nd other-config-flag
R1(config-if)# end

Router Interface Summary Table

Router Model Ethernet Interface #1 Ethernet Interface #2 Serial Interface #1 Serial Interface #2
1800 Fast Ethernet 0/0 (F0/0) Fast Ethernet 0/1 (F0/1) Serial 0/0/0 (S0/0/0) Serial 0/0/1 (S0/0/1)
1900 Gigabit Ethernet 0/0 (G0/0) Gigabit Ethernet 0/1 (G0/1) Serial 0/0/0 (S0/0/0) Serial 0/0/1 (S0/0/1)
2801 Fast Ethernet 0/0 (F0/0) Fast Ethernet 0/1 (F0/1) Serial 0/1/0 (S0/1/0) Serial 0/1/1 (S0/1/1)
2811 Fast Ethernet 0/0 (F0/0) Fast Ethernet 0/1 (F0/1) Serial 0/0/0 (S0/0/0) Serial 0/0/1 (S0/0/1)
2900 Gigabit Ethernet 0/0 (G0/0) Gigabit Ethernet 0/1 (G0/1) Serial 0/0/0 (S0/0/0) Serial 0/0/1 (S0/0/1)
4221 Gigabit Ethernet 0/0/0 (G0/0/0) Gigabit Ethernet 0/0/1 (G0/0/1) Serial 0/1/0 (S0/1/0) Serial 0/1/1 (S0/1/1)
4300 Gigabit Ethernet 0/0/0 (G0/0/0) Gigabit Ethernet 0/0/1 (G0/0/1) Serial 0/1/0 (S0/1/0) Serial 0/1/1 (S0/1/1)

Note: To find out how the router is configured, look at the interfaces to identify the type of router and how many interfaces the router has. There is no way to effectively list all the combinations of configurations for each router class. This table includes identifiers for the possible combinations of Ethernet and Serial interfaces in the device. The table does not include any other type of interface, even though a specific router may contain one. An example of this might be an ISDN BRI interface. The string in parenthesis is the legal abbreviation that can be used in Cisco IOS commands to represent the interface.

Uploading Configuration Files

Use the commands below to create the configuration files on the lab devices for each trouble ticket in this lab. The TCL script commands help create and copy the configurations. However, the configuration commands could also be copied and pasted directly into global config mode on each device. Simply remove the TCL script commands, enter the enable and configure t commands on the device, and copy and paste the configuration commands.

Important: The device requires a folder in flash named enarsi. Use the dir command to verify. If the folder is missing, then create it using the mkdir flash:/enarsi privileged EXEC command. For all switches, make sure the vlan.dat file is set to the default. Use the delete vlan.dat privileged EXEC command, if necessary.

Reset scripts

These TCL scripts will completely clear and reload the device in preparation for the next ticket. Copy and paste the appropriate script to the appropriate device.

Router Reset Script

tclsh
puts [ open "flash:/enarsi/reset.tcl" w+ ] {
typeahead "\n"
copy running-config startup-config
typeahead "\n"
erase startup-config
puts "Reloading the router"
typeahead "\n"
reload
}
tclquit

D1/D2 (Cisco 3650) Reset Script – The default 3650 SDM template supports IPv6, so it is not set by this script.

tclsh
puts [ open "flash:/enarsi/reset.tcl" w+ ] {
typeahead "\n"
copy running-config startup-config
typeahead "\n"
erase startup-config
delete /force vlan.dat
puts "Reloading the switch"
typeahead "\n"
reload
}
tclquit

A1 (Cisco 2960 Script) – The default 2960 SDM template does not support IPv6, so this script includes that setting.

tclsh
puts [ open "flash:/enarsi/reset.tcl" w+ ] {
typeahead "\n"
copy running-config startup-config
typeahead "\n"
erase startup-config
delete /force vlan.dat
delete /force multiple-fs
ios_config "sdm prefer lanbase-routing"
typeahead "\n"
puts "Reloading the switch"
typeahead "\n"
reload
}
tclquit

R1 Configuration File Scripts

!R1 – Trouble Ticket # 1

tclsh
puts [ open "flash:/enarsi/1.1.2.1-r1-config.txt" w+ ] {
hostname R1
banner motd # This is R1, Trouble Ticket 1.1.2.1 #
enable secret cisco12345
username admin privilege 15 algorithm-type scrypt secret cisco12345
ipv6 unicast-routing
interface g0/0/0
ip address 10.10.20.1 255.255.255.0
ipv6 address fe80::1:1 link-local
ipv6 address 2001:db8:a:b::1/64
no shutdown
exit
interface g0/0/1
ip address 10.10.10.1 255.255.255.0
ipv6 address fe80::1:2 link-local
ipv6 address 2001:db8:a:a::1/64
ipv6 nd other-config-flag
ip helper-address 10.10.20.254
ipv6 dhcp relay destination 2001:db8:a:b::2
no shutdown
exit
interface loopback0
ip address 209.165.200.225 255.255.255.248
ipv6 address fe80::1:3 link-local
ipv6 address 2001:db8:a:c::1/64
no shutdown
exit
ip route 0.0.0.0 0.0.0.0 loopback0
ipv6 route ::/0 loopback0
line con 0
exec-timeout 0 0
logging synchronous
exit
line vty 0 4
login local
transport input telnet
exit
alias exec reset.now tclsh flash:/enarsi/reset.tcl
end
}
tclquit

!R1 – Trouble Ticket # 2

tclsh
puts [ open "flash:/enarsi/1.1.2.2-r1-config.txt" w+ ] {
hostname R1
banner motd # This is R1, Trouble Ticket 1.1.2.2 #
enable secret cisco12345
username admin privilege 15 algorithm-type scrypt secret cisco12345
ipv6 unicast-routing
interface g0/0/0
ip address 10.10.20.1 255.255.255.0
ipv6 address fe80::1:1 link-local
ipv6 address 2001:db8:a:b::1/64
ip helper-address 10.10.20.254
no shutdown
exit
interface g0/0/1
ip address 10.10.10.1 255.255.255.0
ipv6 address fe80::1:2 link-local
ipv6 address 2001:db8:a:a::1/64
ipv6 nd other-config-flag
ipv6 dhcp relay destination 2001:db8:a:b::2
no shutdown
exit
interface loopback0
ip address 209.165.200.225 255.255.255.248
ipv6 address fe80::1:3 link-local
ipv6 address 2001:db8:a:c::1/64
no shutdown
exit
ip route 0.0.0.0 0.0.0.0 loopback0
ipv6 route ::/0 loopback0
line con 0
exec-timeout 0 0
logging synchronous
exit
line vty 0 4
login local
transport input telnet
exit
alias exec reset.now tclsh flash:/enarsi/reset.tcl
end
}
tclquit

!R1 – Trouble Ticket # 3

tclsh
puts [ open "flash:/enarsi/1.1.2.3-r1-config.txt" w+ ] {
hostname R1
banner motd # This is R1, Trouble Ticket 1.1.2.3 #
enable secret cisco12345
username admin privilege 15 algorithm-type scrypt secret cisco12345
ipv6 unicast-routing
interface g0/0/0
ip address 10.10.20.1 255.255.255.0
ipv6 address fe80::1:1 link-local
ipv6 address 2001:db8:a:b::1/64
no shutdown
exit
interface g0/0/1
ip address 10.10.10.1 255.255.255.0
ip helper-address 10.10.20.254
ipv6 address fe80::1:2 link-local
ipv6 address 2001:db8:a:a::1/64
ipv6 dhcp relay destination 2001:db8:a:b::2
no shutdown
exit
interface loopback0
ip address 209.165.200.225 255.255.255.248
ipv6 address fe80::1:3 link-local
ipv6 address 2001:db8:a:c::1/64
no shutdown
exit
ip route 0.0.0.0 0.0.0.0 loopback0
ipv6 route ::/0 loopback0
line con 0
exec-timeout 0 0
logging synchronous
exit
line vty 0 4
login local
transport input telnet
exit
alias exec reset.now tclsh flash:/enarsi/reset.tcl
end
}
tclquit

R2 Configuration File Scripts

!R2 – Trouble Ticket # 1

tclsh
puts [ open "flash:/enarsi/1.1.2.1-r2-config.txt" w+ ] {
hostname R2
banner motd # This is R2, Trouble Ticket 1.1.2.1 #
enable secret cisco12345
username admin privilege 15 algorithm-type scrypt secret cisco12345
ipv6 unicast-routing
ip dhcp excluded-address 10.10.10.1 10.10.10.100
ip dhcp pool LAN4_10
network 10.10.10.0 255.255.255.0
default-router 10.10.10.254
domain-name ccnp4lab.com
dns-server 10.10.20.254
exit
ipv6 dhcp pool LAN6_A
dns-server 2001:db8:a:b::1
domain-name ccnp6lab.om
exit
interface g0/0/0
ip address 10.10.20.254 255.255.255.0
ipv6 address fe80::2:1 link-local
ipv6 address 2001:db8:a:b::2/64
ipv6 dhcp server LAN6_A
no shutdown
exit
ip route 0.0.0.0 0.0.0.0 10.10.20.1
ipv6 route ::/0 2001:db8:a:b::1
line con 0
exec-timeout 0 0
logging synchronous
exit
line vty 0 4
login local
transport input telnet
exit
alias exec reset.now tclsh flash:/enarsi/reset.tcl
end
}
tclquit

!R2 – Trouble Ticket # 2

tclsh
puts [ open "flash:/enarsi/1.1.2.2-r2-config.txt" w+ ] {
hostname R2
banner motd # This is R2, Trouble Ticket 1.1.2.2 #
enable secret cisco12345
username admin privilege 15 algorithm-type scrypt secret cisco12345
ipv6 unicast-routing
ip dhcp excluded-address 10.10.10.1 10.10.10.100
ip dhcp pool LAN4_10
network 10.10.10.0 255.255.255.0
default-router 10.10.10.1
domain-name ccnp4lab.com
dns-server 10.10.20.1
exit
ipv6 dhcp pool LAN6_A
dns-server 2001:db8:a:b::1
domain-name ccnp6lab.om
exit
interface g0/0/0
ip address 10.10.20.254 255.255.255.0
ipv6 address fe80::2:1 link-local
ipv6 address 2001:db8:a:b::2/64
ipv6 dhcp server LAN6_A
no shutdown
exit
ip route 0.0.0.0 0.0.0.0 10.10.20.1
ipv6 route ::/0 2001:db8:a:b::1
line con 0
exec-timeout 0 0
logging synchronous
exit
line vty 0 4
login local
transport input telnet
exit
alias exec reset.now tclsh flash:/enarsi/reset.tcl
end
}
tclquit

!R2 – Trouble Ticket # 3

tclsh
puts [ open "flash:/enarsi/1.1.2.3-r2-config.txt" w+ ] {
hostname R2
banner motd # This is R2, Trouble Ticket 1.1.2.3 #
enable secret cisco12345
username admin privilege 15 algorithm-type scrypt secret cisco12345
ipv6 unicast-routing
ip dhcp excluded-address 10.10.10.1 10.10.10.100
ip dhcp pool LAN4_10
network 10.10.10.0 255.255.255.0
default-router 10.10.10.1
domain-name ccnp4lab.com
dns-server 10.10.20.1
exit
ipv6 dhcp pool LAN6_A
dns-server 2001:db8:a:b::1
domain-name ccnp6lab.om
exit
interface g0/0/0
ip address 10.10.20.254 255.255.255.0
ipv6 address fe80::2:1 link-local
ipv6 address 2001:db8:a:b::2/64
ipv6 dhcp server LAN6_A
no shutdown
exit
ip route 0.0.0.0 0.0.0.0 10.10.20.1
ipv6 route ::/0 2001:db8:a:b::1
line con 0
exec-timeout 0 0
logging synchronous
exit
line vty 0 4
login local
transport input telnet
exit
alias exec reset.now tclsh flash:/enarsi/reset.tcl
end
}
tclquit

R3 Configuration File Scripts – Not Used in This Lab

D1 Configuration File Scripts

!D1 – Trouble Ticket # 1

tclsh
puts [ open "flash:/enarsi/1.1.2.1-d1-config.txt" w+ ] {
hostname D1
banner motd # This is D1, Trouble Ticket 1.1.2.1 #
enable secret cisco12345
username admin privilege 15 algorithm-type scrypt secret cisco12345
interface range g1/0/1 - 24
switchport mode access
shutdown
exit
interface g1/0/11
switchport mode access
switchport access vlan 10
no shutdown
exit
interface range g1/0/23-24
switchport mode access
switchport access vlan 10
no shutdown
exit
interface vlan 10
ip address 10.10.10.2 255.255.255.0
no shutdown
exit
ip default-gateway 10.10.10.1
line con 0
exec-timeout 0 0
logging synchronous
exit
alias exec reset.now tclsh flash:/enarsi/reset.tcl
end
}
tclquit

!D1 – Trouble Ticket # 2

tclsh
puts [ open "flash:/enarsi/1.1.2.2-d1-config.txt" w+ ] {
hostname D1
banner motd # This is D1, Trouble Ticket 1.1.2.2 #
enable secret cisco12345
username admin privilege 15 algorithm-type scrypt secret cisco12345
interface range g1/0/1 - 24
switchport mode access
shutdown
exit
interface g1/0/11
switchport mode access
switchport access vlan 10
no shutdown
exit
interface range g1/0/23-24
switchport mode access
switchport access vlan 10
no shutdown
exit
interface vlan 10
ip address 10.10.10.2 255.255.255.0
no shutdown
exit
ip default-gateway 10.10.10.1
line con 0
exec-timeout 0 0
logging synchronous
exit
alias exec reset.now tclsh flash:/enarsi/reset.tcl
end
}
tclquit

!D1 – Trouble Ticket # 3

tclsh
puts [ open "flash:/enarsi/1.1.2.3-d1-config.txt" w+ ] {
hostname D1
banner motd # This is D1, Trouble Ticket 1.1.2.3 #
enable secret cisco12345
username admin privilege 15 algorithm-type scrypt secret cisco12345
interface range g1/0/1 - 24
switchport mode access
shutdown
exit
interface g1/0/11
switchport mode access
switchport access vlan 10
no shutdown
exit
interface range g1/0/23-24
switchport mode access
switchport access vlan 10
no shutdown
exit
interface vlan 10
ip address 10.10.10.2 255.255.255.0
no shutdown
exit
ip default-gateway 10.10.10.1
line con 0
exec-timeout 0 0
logging synchronous
exit
alias exec reset.now tclsh flash:/enarsi/reset.tcl
end
}
tclquit

D2 Configuration File Scripts – Not Used in This Lab

A1 Confgiuration Fiel Scripts – Not Used in This Lab

Download 1.1.2 Lab – Troubleshoot IPv4 and IPv6 Addressing Issues .PDF file:


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