Cisco ACI Fabric Forwarding summary

Here’s a great summary of the ACI packet flow in conjunction with Spine and Leaf, a good watch if you have played with any of this technology, in any way. Thank you Lilian Quan. Very helpful 🙂 ….and another good explanation, depending on the sex of your packet.  


Here’s some useful ‘built-in’ Wireshark capability, for troubleshooting on the supervisor. The feature only works with process switched traffic. nexus#ethanalyzer local interface inband capture-filter  “udp port 161” nexus#ethanalyzer local interface inband capture-filter  “udp port 161” detail nexus#ethanalyzer local interface inband capture-filter “udp port 161” write bootflash:snmp.pcap An ACL log is necessary to capture data plane traffic.  Steps for this canContinue reading “Ethanalyzer”

MP-BGP EVPN VXLAN Configuration

Logical Construct of a Multi Tenant VxLAN EVPN with a Single Tenant in a VRF on a Nexux 9k One VLAN maps to one Layer-2 VNI Layer-2 VNI per Layer-2 segment A Tenant can have multiple VLANs, therefore multiple Layer-2 VNIs Traffic within one Layer-2 VNI is bridged Traffic between Layer-2 VINs is routed 1Continue reading “MP-BGP EVPN VXLAN Configuration”

Nexus 9396 duplicate ICMP echo-reply (DUP!)

Inconsistent echo-reply from devices connected via VPC to Nexus 9300 while pinging from the Nexus exec prompt. With some of the testing I receive normal response when pinging from one Nexus,  but no response when pinging from the other.  In another test I receive a normal response to one Nexus, and duplicate replys to the other HNINXP12# pingContinue reading “Nexus 9396 duplicate ICMP echo-reply (DUP!)”