Month: July 2014

Multicast Refresher for CCIEDC

Multicast, the strange, the backwards, the elusive. At least that’s what I used to think about it until I spent some time taking it out to dinner, listening to it, and developing a strong relationship with it. I have Peter Revill and his awesome four part series to thank for that (he’s a good wing man!).

In this post I’ll be following along Peter’s Multicast series. If you’re new to multicast, or just want a quick refresher, head on over to his blog and follow us on this journey.  As a bonus, I may throw in some basic NX-OS multicast at the bottom, as it pertains to OTV.

Follow him on twitter via @ccierants

First, a quick refresher on multicast and related terms. Feel free to revisit these as you follow the post.



Configuring BFD on Nexus NX-OS

BDF is listed in the CCIE Data Center Lab Blueprint as, “1.2.c – Implement BFD for dynamic routing protocols”. In this blog post, I’ll be explaining BFD and going over it’s relevance for dynamic routing protocols. Without further ado.

Bidirectional Forwarding Detection (BFD) is a protocol designed to quickly detect failures in the forwarding-path, and notify the configured protocols (OSPF, EIGRP, BGP, HSRP, etc) immediately, before they’ve even had an opportunity to be aware of the failure themselves. This results in expedited, sub-second detection of failed forwarding-paths, leading to quicker convergence.

BFD on NX-OS runs in Asynchronous mode, where a BFD neighbor relationship session is formed between two adjacent devices, and they exchange control packets to monitor the session. The configurable parameters used in the session include:


Configuring Netflow on Nexus NXOS

This post is a part of my CCIE:DC studies, but will be useful for anyone needing to quickly configure NetFlow in NXOS.  For CCIE:DC purposes, an understanding of how NetFlow is configured in NXOS cannot hurt, especially since it is mentioned in the blueprint (1.5.b – Implement Netflow).

Unlike IOS, there are few steps involved to get Netflow functioning, here is a quick run down:

1. Enable Netflow
2. Configure a Netflow Flow Record
3. Configure a Netflow Flow Exporter
4. Configure a Netflow Flow Monitor
5. Apply the Netflow Monitor to the your L3 interfaces
6. (Optional) Configure a Netflow Sampler
7. (Optional) Configure Netflow timers