Tag Archives: ACI

ARP Gleaning – ACI Master Class

The purpose of these Gleaning ARPs is simply to “tickle” the target station into sending a packet – not because the gateway needs the MAC address of the target! Continue reading

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Posted in ACI, ACI Tutorial, Cisco, Master Class | Tagged , , , | 3 Comments

ISIS, COOP, BGP and MP-BGP in Cisco ACI

Let me start with a picture.  Imagine a simple 2leaf/2spine topology with HostA attached to to Leaf1 and with HostB attached to to Leaf2. Enter IS-IS. The leaves and spines will exchange IS-IS routing updates with each other so that Leaf1 sees that it has two equally good paths to reach Leaf2, and Leaf2 sees that it has two equally good paths to reach Leaf1. Now think about the hosts. This is where COOP comes in. BGP is not needed until an external router is connected. Continue reading

Posted in ACI, ACI configuration, APIC, Cisco, Data Center, Data Centre, EPG, L3 Out, L3out | Tagged , ,

Non overlapping VTEP IP addresses in Cisco ACI

Cisco recommends that “The TEP IP address pool should not overlap with existing IP address pools that may be in use by the servers (in particular, by virtualized servers).”
Let me tell you a reason much closer to reality why you might want to avoid overlapping your Cisco ACI TEP addresses with your locally configured addressing scheme. Continue reading

Posted in ACI, ACI configuration, APIC, Cisco, Data Center, Data Centre | Tagged , , , ,

Cisco ACI Naming Standards

Have you ever wondered what a L3 Out object is, when there no facility to create an object called L3 Out? I managed to solve this and many other ambiguities by developing and adopting a consistent naming standard. Continue reading

Posted in Access Policies, ACI, ACI configuration, Cisco, Data Center, Data Centre, Nexus, Nexus 9000, SDN, Software Defined Networking | Tagged , , , , | 1 Comment

A funny thing happened in the ACI lab today…

I had a Tenant with a statically configured bare metal hosts attached to interface 1/16 on both leaf 101 and leaf 102, but came up with a “invalid-path;invalid-vlan” error on the faults page for the EPG that was being configured … Continue reading

Posted in Access Policies, ACI, ACI configuration, APIC, Data Center, Data Centre | Tagged , , , , , ,

Cisco ACI Per Port VLAN feature

The customer had already tried configuring the ports, but kept getting a “Configuration
failed for … due to Encap Already Used in Another EPG” error, so I looked to use the Per Port VLAN feature to rescue them. Continue reading

Posted in Access Policies, ACI, ACI configuration, ACI Tutorial, Cisco | Tagged , , , , , | 4 Comments

Cisco ACI Tutorial 4 – The Access Policy Chain – a new “interface range” command

The Access Policy Chain – a new “interface range” command Cisco ACI Tutorial – Part 4 Since you no longer have to configure ports on individual switches, but rather configure multiple ports on multiple switches from a central controller, some … Continue reading

Posted in Access Policies, Access Policy Chain, ACI, ACI configuration, ACI Configuration Tutorial Series#1, ACI Tutorial, Cisco, configuration tutorial, Data Center, Data Centre, Nexus, Nexus 9000, SDN, Software Defined Networking, tutorial | Tagged , , , , , , , , , , , , , , , , , , , , , , , , , , , | 5 Comments