###BeginTicket16###
Ticket 16: IPv6 Routing Issue 3
Topology Overview (Actual Troubleshooting lab design is for below network design)
Client Should have IP 10.2.1.3
EIGRP 100 is running between switch DSW1 & DSW2
OSPF (Process ID 1) is running between R1, R2, R3, R4
Network of OSPF is redistributed in EIGRP
BGP 65001 is configured on R1 with Webserver cloud AS 65002
HSRP is running between DSW1 & DSW2 Switches
The company has created the test bed shown in the layer 2 and layer 3 topology exhibits.
This network consists of four routers, two layer 3 switches and two layer 2 switches.
In the IPv4 layer 3 topology, R1, R2, R3, and R4 are running OSPF with an OSPF process
number 1.
DSW1, DSW2 and R4 are running EIGRP with an AS of 10. Redistribution is enabled where necessary.
R1 is running a BGP AS with a number of 65001. This AS has an eBGP connection to AS 65002
in the ISP’s network. Because the company’s address space is in the private range.
R1 is also providing NAT translations between the inside (10.1.0.0/16 & 10.2.0.0/16) networks and
outside (209.65.0.0/24) network.
ASW1 and ASW2 are layer 2 switches.
NTP is enabled on all devices with 209.65.200.226 serving as the master clock source.
The client workstations receive their IP address and default gateway via R4’s DHCP server.
The default gateway address of 10.2.1.254 is the IP address of HSRP group 10 which is running
on DSW1 and DSW2.
In the IPv6 layer 3 topology R1, R2, and R3 are running OSPFv3 with an OSPF process number 6.
DSW1, DSW2 and R4 are running RIPng process name RIP_ZONE.
The two IPv6 routing domains, OSPF 6 and RIPng are connected via GRE tunnel running over the
underlying IPv4 OSPF domain. Redistrution is enabled where necessary.
Recently the implementation group has been using the test bed to do a ‘proof-of-concept’ on
several implementations. This involved changing the configuration on one or more of the devices.
You will be presented with a series of trouble tickets related to issues introduced during these
configurations.
Note: Although trouble tickets have many similar fault indications, each ticket has its own issue
and solution.
Each ticket has 3 sub questions that need to be answered & topology remains same.
Question-1 Fault is found on which device,
Question-2 Fault condition is related to,
Question-3 What exact problem is seen & what needs to be done for solution
###EndTicket16###
The implementation group has been using the test bed to do an IPv6 ‘proof-of-concept1.
After several changes to the network addressing and routing schemes, a trouble ticket has
been opened indicating that the loopback address on R1 (2026::111:1) is not able to ping
the loopback address on DSW2 (2026::102:1).
Use the supported commands to isolate the cause of this fault and answer the following
question.
On which device is the fault condition located?
A.
R1
B.
R2
C.
R3
D.
R4
E.
DSW1
F.
DSW2
G.
ASW1
H.
ASW2
Explanation:
Start to troubleshoot this by pinging the loopback IPv6 address of DSW2 (2026::102:1). This can
be pinged from DSW1, and R4, but not R3 or any other devices past that point. If we look at the
routing table of R3, we see that there is no OSPF neighbor to R4:This is due to mismatched tunnel modes between R3 and R4:
Problem is with R3, and to resolve the issue we should delete the “tunnel mode ipv6” under
interface Tunnel 34.
