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PIM sparse mode with a BSR
Enterprise Advanced 3 devices 4 checked tasks 100 points Plan lab
Three routers in a line. Elect a bootstrap router, let the edge routers learn the rendezvous point from it, and join a group at the far end. You build it in a browser, type real commands at each device, and every task below is
checked against the running configuration — so you find out it is wrong before anybody else does.
Open this lab in the simulator
The simulator runs in your browser with nothing to install. This lab is part of the full simulator: open it free for 7 days with a new account, then with a plan. It needs an account, which keeps your progress.
The scenario
Three routers in a line. Elect a bootstrap router, let the edge routers learn the rendezvous point from it, and join a group at the far end.
Your role: a network engineer on the enterprise team. Level: Advanced Done when: all 4 goals show as passed (100 points).
Network status
Devices: 3 routers, cabled as drawn. No Layer 1 or Layer 2 faults: every link is connected and up. R1, R2, R3 start with an empty configuration. Known problems
None: nothing is misconfigured. The network is simply not finished: what the goals list is what you have to build or secure. Goals
R1 knows the BSR (25 pts) R1 learned the RP (25 pts) R3 built the shared tree (25 pts) The group is joined on R3 (25 pts) The activity, in order
R1 knows the BSR Why: Reading a show command is the core skill of troubleshooting: the output is the truth, not your configuration. Verify with: show ip pim bsr-router R1 learned the RP Why: Reading a show command is the core skill of troubleshooting: the output is the truth, not your configuration. Verify with: show ip pim rp mapping R3 built the shared tree Why: Reading a show command is the core skill of troubleshooting: the output is the truth, not your configuration. Verify with: show ip mroute The group is joined on R3 Why: This is the task that checks your configuration directly: the line must really be there, not just look right. Verify with: show running-config Tips
Work in the order given: later goals depend on the earlier ones. After every change, run the verify command before moving on; do not guess. Stuck? Read the verify output first. It names the interface, neighbour or route that is wrong. Why this matters
Three routers in a line. Elect a bootstrap router, let the edge routers learn the rendezvous point from it, and join a group at the far end.
What you will be able to do
R1 knows the BSR
R1 learned the RP
R3 built the shared tree
The group is joined on R3
The network
Catalyst 8000V — 3 devices in all, already cabled.
Gi1 Gi1 Gi2 Gi1 R1 R2 R3 Drawn from this lab: devices, cables, ports and the addresses already set. Device Model Address already set
R1 Catalyst 8000V configure it R2 Catalyst 8000V configure it R3 Catalyst 8000V configure it
Cabling
R1 Gi1 ↔ R2 Gi1 R2 Gi2 ↔ R3 Gi1
What is configured at the start
Nothing is configured to start with beyond the addresses above: you build the configuration from a clean start.
Tasks, and how each one is checked
Every task is decided by reading the live network — a neighbour in FULL, a ping that succeeds, a line in the running configuration — not by looking for a keyword you typed. The same command shows you what the lab sees.
# Task Pts How to verify it yourself
1 R1 knows the BSR 25 On R1: show ip pim bsr-router output matches 2\.2\.2\.2. 2 R1 learned the RP 25 On R1: show ip pim rp mapping output matches 2\.2\.2\.2. 3 R3 built the shared tree 25 On R3: show ip mroute output matches \(\*, 239\.5\.5\.5\). 4 The group is joined on R3 25 On R3: show running-config contains the line(s) matching ip igmp join-group 239\.5\.5\.5.
Stuck? Ask the coach
Tell the coach what you see or what you tried. It gives you a hint, not the answer, the way a senior engineer would. Included with a free trial or any plan.
Ask the coach
Reference solution
Try it yourself first — the lab checks your work either way. This is one configuration that makes every task pass, device by device:
R1 ip multicast-routing distributed
interface GigabitEthernet1
ip address 10.1.1.1 255.255.255.0
ip pim sparse-mode
no shutdown
exit
interface Loopback0
ip address 1.1.1.1 255.255.255.255
exit
interface Loopback0
ip pim sparse-mode
exit
router ospf 1
network 0.0.0.0 255.255.255.255 area 0
exit R2 ip multicast-routing distributed
interface GigabitEthernet1
ip address 10.1.1.2 255.255.255.0
ip pim sparse-mode
no shutdown
exit
interface GigabitEthernet2
ip address 10.2.2.2 255.255.255.0
ip pim sparse-mode
no shutdown
exit
interface Loopback0
ip address 2.2.2.2 255.255.255.255
exit
interface Loopback0
ip pim sparse-mode
exit
router ospf 1
network 0.0.0.0 255.255.255.255 area 0
exit
ip pim bsr-candidate Loopback0
ip pim rp-candidate Loopback0 R3 ip multicast-routing distributed
interface GigabitEthernet1
ip address 10.2.2.3 255.255.255.0
ip pim sparse-mode
no shutdown
exit
interface Loopback0
ip address 3.3.3.3 255.255.255.255
exit
interface Loopback0
ip pim sparse-mode
exit
router ospf 1
network 0.0.0.0 255.255.255.255 area 0
exit
interface Loopback0
ip igmp join-group 239.5.5.5
exit Related labs
Where to start
The lessons all guided labs plans
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