About this interactive
From the lesson:
- **On:** static. No negotiation; it bundles only with **on** at the other end.
- **LACP** (the IEEE standard): **active** asks for a channel, **passive** answers only if asked. Active plus active or passive works; passive plus passive never starts.
- **PAgP** (Cisco proprietary): **desirable** asks, **auto** answers only if asked. Desirable plus desirable or auto works; auto plus auto never starts.
- **LACP and PAgP do not mix,** and on does not negotiate with either.
LACP was first defined in IEEE 802.3ad and is now defined in IEEE 802.1AX.
What you'll learn
- Predict whether two EtherChannel mode settings form a channel: on with on, LACP active with active or passive, PAgP desirable with desirable or auto
- Explain why the other pairs fail: two waiting ends, static on against a negotiating end, or LACP against PAgP
Aligned to
Cisco CCNA
2.4
Configure and verify Layer 2/Layer 3 EtherChannel (LACP)
Key terms
- Link Aggregation Control Protocol
LACP
- An IEEE 802.3ad protocol that automatically negotiates and manages the bundling of multiple physical Ethernet links into a single logical link aggregation group. LACP enables dynamic detection of compatible links and provides failover if individual member links go down.
- Port Aggregation Protocol
PAgP
- Cisco's proprietary link aggregation negotiation protocol that automatically creates EtherChannels using desirable or auto modes.
- EtherChannel
- Cisco's implementation of link aggregation that bonds multiple physical links into a single logical channel to increase bandwidth and redundancy.
- IEEE 802.3ad
- The original IEEE standard that defined link aggregation, specifying how multiple physical links are combined into a single logical link.
Topics
Etherchannel
Lacp
Pagp
Negotiation Modes
Interactive
Predict
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