1.5.10 Packet Tracer - Verify Directly Connected Networks Answers
Topology
Addressing Table
| Device | Interface | IP Address / Prefix | Default Gateway |
|---|---|---|---|
| R1 | G0/0/0 | 172.16.20.1/25 | N/A |
| G0/0/1 | 172.16.20.129/25 | N/A | |
| S0/1/0 | 209.165.200.225/30 | N/A | |
| PC1 | NIC | 172.16.20.10/25 | 172.16.20.1 |
| PC2 | NIC | 172.16.20.138/25 | 172.16.20.129 |
| R2 | G0/0/0 | 2001:db8:c0de:12::1/64 | N/A |
| G0/0/1 | 2001:db8:c0de:13::1/64 | N/A | |
| S0/1/1 | 2001:db8:c0de:11::1/64 | N/A | |
| fe80::2 | N/A | ||
| PC3 | NIC | 2001:db8:c0de:12::a/64 | fe80::2 |
| PC4 | NIC | 2001:db8:c0de:13::a/64 | fe80::2 |
Objectives
- Verify IPv4 Directly Connected Networks
- Verify IPv6 Directly Connected Networks
- Troubleshoot connectivity issues.
Background
Routers R1 and R2 each have two LANs. Your task is to verify the addressing on each device and verify connectivity between the LANs.
Note: The user EXEC password is cisco. The privileged EXEC password is class.
Instructions
Part 1: Verify IPv4 Directly Connected Networks
Step 1: Verify IPv4 addresses and port status on R1.
a. Check the status of the configured interfaces by filtering the output.
R1# show ip interface brief | exclude unassigned
Interface IP-Address OK? Method Status Protocol
GigabitEthernet0/0/0 172.16.20.1 YES manual administratively down down
GigabitEthernet0/0/1 172.16.20.129 YES manual up up
Serial0/1/0 209.165.200.229 YES manual up upb. Based on the output, correct any port status problems that you see.
GigabitEthernet0/0/0 is administratively down. To enable it:
R1(config)# interface gigabitethernet 0/0/0 R1(config-if)# no shutdown
c. Refer to the Addressing Table and verify the IP addresses configured on R1. Make any corrections to addressing if necessary.
R1# show running-config
Building configuration...
Current configuration : 977 bytes
!
version 15.4
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname R1
!
<output omitted>
!
interface Serial0/1/0
description Circuit ID BCB123450001
ip address 209.165.200.229 255.255.255.248
clock rate 2000000The IP address and subnet mask on interface Serial0/1/0 are incorrect. To correct them:
R1(config)# interface serial 0/1/0 R1(config-if)# ip address 209.165.200.225 255.255.255.252
d. Display the routing table by filtering to start the output at the word Gateway.
Note: Terms that are used to filter output can be shortened to match text as long as the match is unique. For example, Gateway, Gate, and Ga will have the same effect. G will not. Filtering is case-sensitive.
R1# show ip route | begin Gate
Gateway of last resort is 209.165.200.226 to network 0.0.0.0
172.16.0.0/16 is variably subnetted, 4 subnets, 2 masks
C 172.16.20.0/25 is directly connected, GigabitEthernet0/0/0
L 172.16.20.1/32 is directly connected, GigabitEthernet0/0/0
C 172.16.20.128/25 is directly connected, GigabitEthernet0/0/1
L 172.16.20.129/32 is directly connected, GigabitEthernet0/0/1
209.165.200.0/24 is variably subnetted, 2 subnets, 2 masks
C 209.165.200.224/30 is directly connected, Serial0/1/0
L 209.165.200.225/32 is directly connected, Serial0/1/0
S* 0.0.0.0/0 [1/0] via 209.165.200.226What is the Gateway of last resort address?
209.165.200.226
e. Display interface information and filter for Description or connected.
Note: When using include or exclude multiple searches can be performed by separating the search strings with a pipe symbol ( | ).
R1# show interfaces | include Desc|conn
GigabitEthernet0/0/0 is up, line protocol is up (connected)
Description: Connection to SW1
GigabitEthernet0/0/1 is up, line protocol is up (connected)
Description: Connection to SW2
Serial0/1/0 is up, line protocol is up (connected)
Description: Circuit ID BCB123450001
R1#What is the Circuit ID displayed from your output?
BCB123450001
f. Display specific interface information for G0/0/0 by filtering for duplex.
R1# show interfaces gigabitethernet 0/0/0 | include duplex Full-duplex, 100Mb/s, media type is RJ45
What is the duplex setting, speed, and media type?
Full-duplex, 100Mb/s, media type is RJ45
Step 2: Verify connectivity.
PC1 and PC2 should be able to ping each other and the Dual Stack Server. If not, verify the status of the interfaces and the IP address assignments.
Part 2: Verify IPv6 Directly Connected Networks
Step 1: Verify IPv6 addresses and port status on R2.
a. Check the status of the configured interfaces.
R2# show ipv6 interface brief GigabitEthernet0/0/0 [up/up] FE80::2 2001:DB8:C0DE:12::1 GigabitEthernet0/0/1 [up/up] FE80::2 2001:DB8:C0DE:14::1 Serial0/1/0 [administratively down/down] unassigned Serial0/1/1 [up/up] FE80::2D0:BCFF:FE32:7C24 2001:DB8:C0DE:11::1 Vlan1 [administratively down/down] unassigned R2#
What is the status of the configured interfaces?
All configured interfaces are up/up.
b. Refer to the Addressing Table and make any corrections to addressing as necessary.
Note: When changing an IPv6 address it is necessary to remove the incorrect address since an interface is capable of supporting multiple IPv6 networks.
R2(config)# interface gigabitethernet 0/0/1 R2(config-if)# no ipv6 address 2001:db8:c0de:14::1/64
Configure the correct address on the interface.
R2(config-if)# ipv6 address 2001:db8:c0de:13::1/64
c. Display the IPv6 routing table.
Note: Filtering commands do not presently work with the IPv6 commands.
R2# show ipv6 route
IPv6 Routing Table - 8 entries
Codes: C - Connected, L - Local, S - Static, R - RIP, B - BGP
U - Per-user Static route, M - MIPv6
I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary
O - OSPF intra, OI - OSPF inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2
ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2
D - EIGRP, EX - EIGRP external
S ::/0 [1/0]
via Serial0/1/1, directly connected
C 2001:DB8:C0DE:11::/64 [0/0]
via Serial0/1/1, directly connected
L 2001:DB8:C0DE:11::1/128 [0/0]
via Serial0/1/1, receive
C 2001:DB8:C0DE:12::/64 [0/0]
via GigabitEthernet0/0/0, directly connected
L 2001:DB8:C0DE:12::1/128 [0/0]
via GigabitEthernet0/0/0, receive
C 2001:DB8:C0DE:13::/64 [0/0]
via GigabitEthernet0/0/1, directly connected
L 2001:DB8:C0DE:13::1/128 [0/0]
via GigabitEthernet0/0/1, receive
L FF00::/8 [0/0]
via Null0, received. Display all IPv6 addressing configured on interfaces by filtering the output of the running-config.
Filter the output on R2 for ipv6 or interface.
R2# show running-config | include ipv6|interface ipv6 unicast-routing no ipv6 cef interface GigabitEthernet0/0/0 ipv6 address FE80::2 link-local ipv6 address 2001:DB8:C0DE:12::1/64 ipv6 enable interface GigabitEthernet0/0/1 ipv6 address FE80::2 link-local ipv6 address 2001:DB8:C0DE:13::1/64 ipv6 enable interface Serial0/1/0 interface Serial0/1/1 ipv6 address 2001:DB8:C0DE:11::1/64 ipv6 enable interface Vlan1 ipv6 route ::/0 Serial0/1/1
How many addresses are configured on each Gigabit interface?
There are 2 IPv6 addresses. The IPv6 /64 address and the IPv6 link-local address.
Step 2: Verify connectivity.
PC3 and PC4 should be able to ping each other and the Dual Stack Server. If not, verify the interface status and IPv6 address assignments.
Device Configs - Final
Issues Found and Solutions
Both routers are preconfigured, but three faults were introduced. Each one is found by reading the filtered show output described in the lab.
| # | Device | Issue | Solution |
|---|---|---|---|
| 1 | R1 — G0/0/0 | Interface is administratively down, so the PC1 LAN is unreachable | Apply no shutdown |
| 2 | R1 — S0/1/0 | Wrong IPv4 address 209.165.200.229 — this lands in the 209.165.200.228/30 subnet, so the default-route next hop 209.165.200.226 is unreachable |
Set it to 209.165.200.225 255.255.255.252 |
| 3 | R2 — G0/0/1 | Wrong IPv6 prefix 2001:db8:c0de:14::1/64 — PC4's LAN is 2001:db8:c0de:13::/64 |
Remove the wrong address, then apply 2001:db8:c0de:13::1/64 |
Why the serial address matters: a /30 has only two usable hosts. With 209.165.200.225, the subnet is 209.165.200.224/30 and the two hosts are .225 and .226 — so the gateway of last resort (.226) sits on the same link. With the faulty .229, the subnet becomes 209.165.200.228/30 (hosts .229 and .230), and .226 is no longer directly connected at all.
ROUTER R1
! ============================================================== !--- 1.5.10 Packet Tracer - Verify Directly Connected Networks !--- FIX SCRIPT FOR ROUTER R1 !--- Usage: on the R1 console, log in with the user EXEC password "cisco", type "enable" and enter the privileged EXEC password "class", then paste this whole file at the R1# prompt. Every line beginning with "!" is a comment; IOS ignores it, so pasting a comment by accident is harmless. !--- This is a VERIFY / TROUBLESHOOT lab: the script applies only the corrective commands for the faults found with the show commands. ! ============================================================== configure terminal ! -------------------------------------------------------------- !--- Fault 1: G0/0/0 was administratively down, so the PC1 LAN (172.16.20.0/25) was unreachable. Found with: show ip interface brief | exclude unassigned ! -------------------------------------------------------------- !--- Bring the LAN interface back up. interface gigabitethernet 0/0/0 no shutdown exit ! -------------------------------------------------------------- !--- Fault 2: S0/1/0 had the wrong IPv4 address (209.165.200.229 instead of 209.165.200.225), which put it in the wrong /30 subnet - the default route next hop 209.165.200.226 was therefore unreachable. ! -------------------------------------------------------------- !--- Correct the WAN address. On IPv4 the new primary address automatically replaces the old one, so no 'no ip address' is needed first. interface serial 0/1/0 ip address 209.165.200.225 255.255.255.252 exit end ! -------------------------------------------------------------- !--- Save the configuration to NVRAM. (Press Enter when prompted for the destination filename.) ! -------------------------------------------------------------- copy running-config startup-config ! ============================================================== !--- Verification: !--- show ip interface brief | exclude unassigned -> all three interfaces up/up !--- show ip route | begin Gate -> Gateway of last resort is 209.165.200.226 !--- show interfaces | include Desc|conn -> descriptions and link state !--- show interfaces gigabitethernet 0/0/0 | include duplex -> Full-duplex, 100Mb/s, RJ45 !--- From PC1 and PC2: ping each other and the Dual Stack Server. ! ==============================================================
ROUTER R2
! ============================================================== !--- 1.5.10 Packet Tracer - Verify Directly Connected Networks !--- FIX SCRIPT FOR ROUTER R2 !--- Usage: on the R2 console, log in with the user EXEC password "cisco", type "enable" and enter the privileged EXEC password "class", then paste this whole file at the R2# prompt. Every line beginning with "!" is a comment; IOS ignores it, so pasting a comment by accident is harmless. !--- This is a VERIFY / TROUBLESHOOT lab: the script applies only the corrective commands for the faults found with the show commands. ! ============================================================== configure terminal ! -------------------------------------------------------------- !--- Fault 3: G0/0/1 had the wrong IPv6 prefix (2001:db8:c0de:14::1/64 instead of :13::1/64), so PC4's LAN did not match its gateway. Found with: show ipv6 interface brief ! -------------------------------------------------------------- !--- IMPORTANT: unlike IPv4, an interface can hold MULTIPLE IPv6 addresses - a new one does NOT replace the old one. The wrong prefix must be removed explicitly, or both will stay active. interface gigabitethernet 0/0/1 no ipv6 address 2001:db8:c0de:14::1/64 !--- Apply the correct prefix from the Addressing Table. The link-local fe80::2 (PC4's default gateway) is already configured on this interface and is not affected. ipv6 address 2001:db8:c0de:13::1/64 exit end ! -------------------------------------------------------------- !--- Save the configuration to NVRAM. (Press Enter when prompted for the destination filename.) ! -------------------------------------------------------------- copy running-config startup-config ! ============================================================== !--- Verification: !--- show ipv6 interface brief -> G0/0/1 shows 2001:DB8:C0DE:13::1 + FE80::2 !--- show ipv6 route -> the connected IPv6 LANs !--- show running-config | include ipv6|interface -> 2 addresses per Gigabit interface !--- From PC3 and PC4: ping each other and the Dual Stack Server. ! ==============================================================
Important IPv4 vs IPv6 difference: on an IPv4 interface, a new primary address automatically replaces the old one. On an IPv6 interface, an interface can hold multiple addresses, so the incorrect address must be removed explicitly with no ipv6 address — otherwise both prefixes stay active on the interface.
