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IS-IS levels and the attached bit
Service Provider Advanced 3 devices 5 checked tasks 100 points Plan lab
A backbone router, a border router and an access router in another area. Build the levels so the access router needs nothing but a default route. 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
A backbone router, a border router and an access router in another area. Build the levels so the access router needs nothing but a default route.
Your role: an engineer in the provider’s network operations centre. Level: Advanced Done when: all 5 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. A, B, C 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
A has one L2 neighbour (20 pts) A has the far loopback (25 pts) C has a default from the attached border router (25 pts) C holds no backbone prefix (10 pts) A reaches C (20 pts) The activity, in order
A has one L2 neighbour Why: Each goal is a state the lab can check on the running device. Verify with: show running-config A has the far loopback Why: If the prefix is not in the routing table, the router drops packets for it, whatever else is configured. Verify with: show ip route C has a default from the attached border router Why: If the prefix is not in the routing table, the router drops packets for it, whatever else is configured. Verify with: show ip route C holds no backbone prefix Why: A route that should not exist is a leak or a loop waiting to happen. Verify with: show ip route A reaches C Why: A ping needs a route in BOTH directions. This is the end-to-end proof that everything before it worked. Verify with: ping 3.3.3.3 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
A backbone router, a border router and an access router in another area. Build the levels so the access router needs nothing but a default route.
What you will be able to do
A has one L2 neighbour
A has the far loopback
C has a default from the attached border router
C holds no backbone prefix
The network
Catalyst 8000V — 3 devices in all, already cabled.
Gi1 Gi1 Gi2 Gi1 A B C Drawn from this lab: devices, cables, ports and the addresses already set. Device Model Address already set
A Catalyst 8000V configure it B Catalyst 8000V configure it C Catalyst 8000V configure it
Cabling
A Gi1 ↔ B Gi1 B Gi2 ↔ C 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 A has one L2 neighbour 20 Checked automatically against the device’s live state (isisNbrs). 2 A has the far loopback 25 On A: show ip route lists 3.3.3.3/32. 3 C has a default from the attached border router 25 On C: show ip route lists 0.0.0.0/0. 4 C holds no backbone prefix 10 On C: show ip route does not list 1.1.1.1/32. 5 A reaches C 20 On A: ping 3.3.3.3 must succeed.
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:
A interface Loopback0
ip address 1.1.1.1 255.255.255.255
ip router isis
exit
interface GigabitEthernet1
ip address 10.1.1.1 255.255.255.0
ip router isis
isis network point-to-point
no shutdown
exit
router isis
net 49.0001.0000.0000.0001.00
is-type level-2-only
metric-style wide
exit B interface GigabitEthernet1
ip address 10.1.1.2 255.255.255.0
ip router isis
isis network point-to-point
no shutdown
exit
interface GigabitEthernet2
ip address 10.2.2.2 255.255.255.0
ip router isis
no shutdown
exit
router isis
net 49.0002.0000.0000.0002.00
metric-style wide
exit C interface Loopback0
ip address 3.3.3.3 255.255.255.255
ip router isis
exit
interface GigabitEthernet1
ip address 10.2.2.3 255.255.255.0
ip router isis
no shutdown
exit
router isis
net 49.0002.0000.0000.0003.00
is-type level-1
metric-style wide
exit Related labs
Where to start
The lessons all guided labs plans
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