16.3.2 Packet Tracer - Troubleshoot IPv4 and IPv6 Static and Default Routes - Physical Mode Answers
Topology
Addressing Table
| Device | Interface | IP Address / Prefix | Default Gateway |
|---|---|---|---|
| R1 | G0/0/0 | 192.168.0.1/28 | N/A |
| 2001:db8:acad::1/64 | |||
| G0/0 | 192.168.0.17/28 | ||
| 2001:db8:acad:16::1/64 | |||
| G0/1 | 172.16.1.1/24 | ||
| 2001:db8:acad:171::1/64 | |||
| G0/2 | 209.165.200.1 /25 | ||
| 2001:db8:acad:209::1/64 | |||
| R2 | G0/0/0 | 192.168.0.14/28 | N/A |
| 2001:db8:acad::14/64 | |||
| G0/0 | 192.168.0.30/28 | ||
| 2001:db8:acad:16::2/64 | |||
| G0/1 | 172.16.2.1/24 | ||
| 2001:db8:acad:172::1/64 | |||
| G0/2 | 209.165.200.129/25 | ||
| 2001:db8:acad:210::1/64 | |||
| PC1 | NIC | 172.16.1.2 /24 | 172.16.1.1 |
| 2001:db8:acad:171::2/64 | fe80::1 | ||
| PC2 | NIC | 209.165.200.2/25 | 209.165.200.1 |
| 2001:db8:acad:209::2/64 | fe80::1 | ||
| PC3 | NIC | 172.16.2.2/24 | 172.16.2.1 |
| 2001:db8:acad:172::2/64 | fe80::2 | ||
| PC4 | NIC | 209.165.200.130/25 | 209.265.200.129 |
| 2001:db8:acad:210::2/64 | fe80::2 |
Objectives
- Part 1: Evaluate Network Operation
- Part 2: Gather Information, Create an Action Plan, and Implement Corrections
Background / Scenario
All the network devices in this Packet Tracer Physical Mode (PTPM) activity have been preconfigured to include intentional errors that are preventing the network from routing as intended. Your task is to evaluate the network, identify, and correct the configuration errors to restore full connectivity. You may find errors with the route statements or with other configurations that impact the accuracy of the route statements.
Note: The static routing approach used in this activity is used to assess your ability to configure different types of static routes only. This approach may not reflect networking best practices.
Instructions
Part 1: Evaluate Network Operation
Use the ping and/or traceroute commands from the router to test the following criteria and record the results.
Note: Use the PCs in the wiring closet to gain console access to networking devices in order to explore and change the device configurations.
- Traffic from R1 to the 172.16.2.1 address on R2 uses the next hop 192.168.0.14.
- Traffic from R1 to the 209.165.200.129 address on R2 uses the next hop 192.168.0.30.
- When the G0/0/0 interface on R1 is shut down, traffic from R1 to the 172.16.2.1 address on R2 uses the next hop 192.168.0.30.
- Traffic from R2 to the 2001:db8:acad:171::1 address on R1 uses the next hop 2001:db8:acad::1.
- Traffic from R2 to the 2001:db8:acad:209::1 address on R1 uses the next hop 2001:db8:acad:16::1.
- When the G0/0/0 interface on R2 is shut down, traffic from R2 to the 2001:db8:acad:171::1 address on R1 uses the next hop 2001:db8:acad:16::1.
Part 2: Gather Information, Create an Action Plan, and Implement Corrections
a. For each criterion that is not met, gather information by examining the running configuration and routing tables to develop a hypothesis for what is causing the malfunction.
b. Create an action plan that you think will fix the issue. Develop a list of all the commands you intend to use to fix the issue, and a list of all the commands you need to revert the configuration, should your action plan fail to correct the issue.
c. Execute your action plans one at a time for each criterion that fails, and record the fix actions.
Routing problems on both routers:
- 1. Wrong IP for next hop
- 2. AD set high versus default
- 3. Default AD used and wrong next hop IP
Device Configs - Final
ROUTER R1
! ============================================================== !--- 16.3.2 Packet Tracer - Troubleshoot IPv4 and IPv6 Static and Default Routes - Physical Mode !--- FIX SCRIPT FOR ROUTER R1 !--- Usage: from the console on R1, enter privileged EXEC mode with "enable", then paste this whole file. Every line beginning with "!" is a comment; IOS ignores it, so pasting a comment by accident is harmless. !--- Verified against the actual "show running-config" you provided: all three "no ip route" removals below match the real broken routes exactly (destination, mask, next-hop, and AD all confirmed) - no typos found, unlike some other troubleshooting labs. R1's IPv6 default route (via the switch path, 2001:DB8:ACAD:16::2) is untouched on purpose - Part 1's test criteria only exercise IPv4 behavior on R1 (IPv6 is R2's side of the testing split), so it's out of scope here. ! ============================================================== enable configure terminal ! -------------------------------------------------------------- !--- Problem 1 (Wrong IP for next hop): the route to R2's G0/2 subnet (209.165.200.128/25) pointed at 192.168.0.3, which isn't any real interface address on this /28. It should point at R2's G0/0 (the switch-redundant path). ! -------------------------------------------------------------- no ip route 209.165.200.128 255.255.255.128 192.168.0.3 ip route 209.165.200.128 255.255.255.128 192.168.0.30 ! -------------------------------------------------------------- !--- Problem 2 (AD set high versus default): the PRIMARY default route (via R2's direct WAN address, .14) had been given AD 80 - a floating-route AD - instead of the default AD of 1, so it was never actually winning over anything. ! -------------------------------------------------------------- no ip route 0.0.0.0 0.0.0.0 192.168.0.14 80 ip route 0.0.0.0 0.0.0.0 192.168.0.14 ! -------------------------------------------------------------- !--- Problem 3 (Default AD used and wrong next hop IP): the FLOATING default route had two stacked errors - it used the default AD (1, same as the primary, so it could never truly float) AND pointed at the same nonexistent 192.168.0.3 address as Problem 1. Fixed with the correct next-hop (R2's switch-path address, .30) and an explicit AD of 80. ! -------------------------------------------------------------- no ip route 0.0.0.0 0.0.0.0 192.168.0.3 ip route 0.0.0.0 0.0.0.0 192.168.0.30 80 end ! -------------------------------------------------------------- !--- Operational habit (not explicitly required by this lab): save to NVRAM. (Press Enter when prompted for the destination filename.) ! -------------------------------------------------------------- copy running-config startup-config ! ============================================================== !--- Verification (matches Part 1's stated test criteria exactly): !--- R1# show ip route static -> 209.165.200.128/25 via 192.168.0.30; 0.0.0.0/0 via 192.168.0.14 (AD 1, active) with 192.168.0.30 as a floating backup (AD 80, not shown unless the primary is down) !--- From R1, traffic to 172.16.2.1 (R2's LAN) -> next hop 192.168.0.14 !--- From R1, traffic to 209.165.200.129 -> next hop 192.168.0.30 !--- Shut down G0/0/0 on R1 -> traffic to 172.16.2.1 now uses next hop 192.168.0.30 ! ==============================================================
ROUTER R2
! ============================================================== !--- 16.3.2 Packet Tracer - Troubleshoot IPv4 and IPv6 Static and Default Routes - Physical Mode !--- FIX SCRIPT FOR ROUTER R2 !--- Usage: from the console on R2, enter privileged EXEC mode with "enable", then paste this whole file. Every line beginning with "!" is a comment; IOS ignores it, so pasting a comment by accident is harmless. !--- Verified against the actual "show running-config" you provided: all three "no ipv6 route" removals below match the real broken routes exactly (destination, next-hop, and AD all confirmed) - no typos found. In particular, the "DB7" in the first route really is the actual broken value in your configuration (not a mistake introduced here). R2's IPv4 default route (via the switch path, 192.168.0.17) is untouched on purpose - Part 1's test criteria only exercise IPv6 behavior on R2 (IPv4 is R1's side of the testing split), so it's out of scope here. ! ============================================================== enable configure terminal ! -------------------------------------------------------------- !--- Problem 1 (Wrong IP for next hop): the route to R1's G0/2 subnet (2001:db8:acad:209::/64) pointed at 2001:DB7:ACAD:16::1 - "DB7" instead of "DB8" - which isn't a real address anywhere in this topology. It should point at R1's G0/0 (the switch-redundant path). ! -------------------------------------------------------------- no ipv6 route 2001:db8:acad:209::/64 2001:db7:acad:16::1 ipv6 route 2001:db8:acad:209::/64 2001:db8:acad:16::1 ! -------------------------------------------------------------- !--- Problem 2 (AD set high versus default): the PRIMARY default route (via R1's direct WAN address) had been given AD 90 - a floating-route AD - instead of the default AD of 1, so it was never actually winning over anything. ! -------------------------------------------------------------- no ipv6 route ::/0 2001:db8:acad::1 90 ipv6 route ::/0 2001:db8:acad::1 ! -------------------------------------------------------------- !--- Problem 3 (Default AD used and wrong next hop IP): the FLOATING default route had two stacked errors - it used the default AD (1, same as the primary, so it could never truly float) AND pointed at a nonexistent address (2001:DB8:ACAD:15::1 - "15" instead of "16"). Fixed with the correct next-hop (R1's switch-path address) and an explicit AD of 80. ! -------------------------------------------------------------- no ipv6 route ::/0 2001:db8:acad:15::1 ipv6 route ::/0 2001:db8:acad:16::1 80 end ! -------------------------------------------------------------- !--- Operational habit (not explicitly required by this lab): save to NVRAM. (Press Enter when prompted for the destination filename.) ! -------------------------------------------------------------- copy running-config startup-config ! ============================================================== !--- Verification (matches Part 1's stated test criteria exactly): !--- R2# show ipv6 route static -> 2001:db8:acad:209::/64 via 2001:db8:acad:16::1; ::/0 via 2001:db8:acad::1 (AD 1, active) with 2001:db8:acad:16::1 as a floating backup (AD 80) !--- From R2, traffic to 2001:db8:acad:171::1 (R1's LAN) -> next hop 2001:db8:acad::1 !--- From R2, traffic to 2001:db8:acad:209::1 -> next hop 2001:db8:acad:16::1 !--- Shut down G0/0/0 on R2 -> traffic to 2001:db8:acad:171::1 now uses next hop 2001:db8:acad:16::1 ! ==============================================================
