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EtherChannel 11 — Po3, active/passive
Enterprise Intermediate 4 devices 3 checked tasks 100 points Plan lab
Two cables join SW-A and SW-B. Bundle Gi0/1-2 into port-channel 3 with active on A and passive on B, so the pair carries traffic as one link and spanning tree sees one port. 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
Two cables join SW-A and SW-B. Bundle Gi0/1-2 into port-channel 3 with active on A and passive on B, so the pair carries traffic as one link and spanning tree sees one port.
Your role: a network engineer on the enterprise team. Level: Intermediate Done when: all 3 goals show as passed (100 points).
Network status
Devices: 2 switchs, 2 PCs, cabled as drawn. No Layer 1 or Layer 2 faults: every link is connected and up. PC-A is a host with 10.30.0.11/24. PC-B is a host with 10.30.0.12/24. SW-A, SW-B 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
SW-A has Po3 with both ports bundled (35 pts) SW-B shows Po3 in use (SU) (35 pts) The PCs reach each other (30 pts) The activity, in order
SW-A has Po3 with both ports bundled Why: EtherChannel joins links into one logical link, so spanning tree does not block the extras. Verify with: show etherchannel summary SW-B shows Po3 in use (SU) Why: Reading a show command is the core skill of troubleshooting: the output is the truth, not your configuration. Verify with: show etherchannel summary The PCs reach each other Why: A ping needs a route in BOTH directions. This is the end-to-end proof that everything before it worked. Verify with: ping 10.30.0.12 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. Common mistake: Mixing LACP with PAgP modes Common mistake: Different speed/duplex/VLAN settings on the member ports Common mistake: Both sides passive or auto — nobody starts the negotiation Why this matters
Parallel links between switches would normally leave one blocked by spanning tree. An EtherChannel bundles them into one logical link, so the bandwidth is used and a cable failure costs nothing.
What you will be able to do
Configure LACP, PAgP or static channel groups
Pick compatible modes on both ends
Read show etherchannel summary
The network
Catalyst 2960-24TT, PC — 4 devices in all, already cabled.
Gi0/1 Gi0/1 Gi0/2 Gi0/2 Fa0/1 Fa0 Fa0/1 Fa0 SW-A SW-B PC-A 10.30.0.11/24 PC-B 10.30.0.12/24 Drawn from this lab: devices, cables, ports and the addresses already set. Device Model Address already set
SW-A Catalyst 2960-24TT configure it SW-B Catalyst 2960-24TT configure it PC-A PC 10.30.0.11 / 255.255.255.0 PC-B PC 10.30.0.12 / 255.255.255.0
Cabling
SW-A Gi0/1 ↔ SW-B Gi0/1 SW-A Gi0/2 ↔ SW-B Gi0/2 SW-A Fa0/1 ↔ PC-A Fa0 SW-B Fa0/1 ↔ PC-B Fa0
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 SW-A has Po3 with both ports bundled 35 On SW-A: show etherchannel summary — the port-channel has 2 bundled members. 2 SW-B shows Po3 in use (SU) 35 On SW-B: show etherchannel summary output matches Po3\(SU\). 3 The PCs reach each other 30 On PC-A: ping 10.30.0.12 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
Common mistakes
Mixing LACP with PAgP modes
Different speed/duplex/VLAN settings on the member ports
Both sides passive or auto — nobody starts the negotiation
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:
SW-A interface range g0/1 - 2
channel-group 3 mode active
exit SW-B interface range g0/1 - 2
channel-group 3 mode passive
exit Where this is examined
CCNA 2.0 EtherChannel; CCNP ENCOR Layer 2.
This lab practises these topics in the zNetLaB certification courses:
EtherChannel (LACP/PAgP) — CCNA · Network Access Trunking, EtherChannel, RSTP and MST — CCNP Enterprise · ENCOR · Infrastructure Switched campus: VTPv3, MST, EtherChannel, UDLD, loop guard — CCIE Enterprise Infrastructure · Network Infrastructure VLANs, trunking, STP, EtherChannel, VTP — CompTIA Network+ · Network Implementation EtherChannel — Switching and VLAN Mastery · Loop prevention and bundling
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