LACP Fallback - Explanation
What Problem Does It Solve?
Without LACP Fallback:
- Port-Channel waits for full LACP negotiation before forwarding ANY traffic
- If LACP PDUs are delayed…
Status Update - Partial Fix Applied
Completed:
- ✅ leaf1.cfg - LACP fallback added
- ✅ leaf2.cfg - LACP fallback added
Remaining (need same 2-line addition to Port-Channel1): -…
Fix Applied - Adding LACP Fallback to All Leafs
Fix: Add LACP fallback configuration to Port-Channel1 on all 8 leaf switches.
interface Port-Channel1
port-channel lacp fallback…
SOLUTION FOUND - LACP Fallback Configuration
After reviewing Arista MLAG best practices, the issue is that Port-Channel1 needs LACP fallback or the port-channel needs to allow the link to…
NEW THEORY - Check LACP System Priority
Comparing with the working srl-evpn-mh-lab example, there might be missing LACP configuration on the switch side.
On Arista switches with MLAG,…
Root Cause Confirmed
Checking the configs and topology:
Topology (evpn-lab.clab.yml): Hosts are STILL configured for dual-homing with LACP bonding (mode 802.3ad) Leaf configs: All…
✅ Config Update Status
Completed:
- ✅ leaf1.cfg -
no shutdownadded to Port-Channel1 - ✅ leaf2.cfg -
no shutdownadded to Port-Channel1 - ✅ leaf3.cfg -
no shutdownadded to…
🔧 FOUND THE ISSUE: Port-Channel1 is administratively down
Root Cause: Port-Channel1 missing no shutdown command
Quick Fix - Run this now on all leafs:
for leaf in leaf1…
Port-Channel Status Check Needed
Host bonding looks good (bond0 is UP with both eth1 and eth2 as members), but Port-Channel1 on the leaf switches likely needs verification.
**Run these…