Building network automation solutions

9 module online course

Start now!

Blog Posts in March 2014

New webinar: Following Packets across Overlay Virtual Networks

Even though I’ve been talking and writing about various overlay virtual networking solutions for years (overview, Hyper-V, Amazon VPC, VMware NSX layer-2 and layer-3 gateways), there are still questions along the lines of “how does a packet get from A to B”, so Ethan Banks asked me to do a 1-hour session at upcoming Interop in Las Vegas.

Expanded version of the same presentation will be available as an update session to all current and future attendees of Overlay Virtual Networking webinar:

read more add comment

Scaling BGP-Based DMVPN Networks

Cristiano sent me an interesting question:

I saw that to configure BGP as the routing protocol running over DMVPN I have to configure BGP neighbors on the hub site router. Do I really have to configure all the neighbors on the hub site? How many neighbors could I configure? How can I scale that?

According to Cisco Live presentations, BGP-over-DMVPN scales to several thousand spoke sites (per hub router), so you shouldn’t be too worried about the protocol scalability. Configuring all those neighbors is a different issue.

read more see 21 comments

Scale-Out Load Balancing with OpenFlow

When OpenFlow was still fresh and exciting, someone made quite a name for himself by proposing a global load-balancing solution that would install per-session OpenFlow entries in every core switch around the world. Clearly a great idea, mimicking the best experiences we had with ATM SVCs.

Meanwhile some people started using OpenFlow in real-life networks for coarse-grained load balancing that improves the scalability of stateful network services. For more details, watch the video recorded during the Real Life OpenFlow-based SDN Use Cases webinar.

see 2 comments

MPLS Requires Custom Silicon. Really?

I heard the following pretty bold statement while listening to an episode of my favorite podcast: “Bringing MPLS into the data center is impractical because MPLS requires custom silicon.” Really? How about checking the Intel FM 6000 product brief first?

Broadcom Trident chipset supposedly also supports MPLS. I couldn’t verify that because Broadcom considers the capabilities of their hardware highly confidential (but if you know more, do write a comment). Absolutely refreshing for a chipset that you get in almost every ToR switch you buy.

read more see 10 comments

SDN Workshop @ Troopers 2014

If you plan to attend the Troopers 2014 conference in two weeks, don’t forget to include my full-day SDN workshop on Tuesday in your agenda (the Troopers conference is sold out, but you can still register for the workshop). The topics of the workshop will include:

  • Why do we need SDN and what is it?
  • OpenFlow, its advantages, drawbacks and scalability challenges;
  • Typical OpenFlow and SDN deployment considerations;
  • Real-life SDN use cases, both OpenFlow- and non-OpenFlow ones;
  • Network function virtualization;
  • Software-defined data centers.

For more details, check out the workshop description; for other SDN-related materials visit my SDN Resources page.

add comment

Whose Failure Domain Is It?

Draco made a valid comment to my Keep Your Failure Domain Small post:

What could a small ISP do to limit failure domains? Metro Ethernet and MPLS Virtual Private LAN service are all the rage, and offers customers the promise of being able to connect all their branch offices together, and use the same set of VLANs with free Layer 2 connectivity between their sites. It's either: extend the failure domains, or lose out in selling the service, b/c the customer will buy from another ISP.

Well, your customer’s failure domain doesn’t have to be yours.

read more see 1 comments

Network Automation: Just Do It!

On the very same day that I published the CLI is Not the Problem post I stumbled upon an interesting discussion on the v6ops mailing list. It all started with a crazy idea to modify BGP to use 128-bit router ID to help operators that think they can manually configure large IPv6-only networks without any centralized configuration/management authority that would assign 32 bit identifiers to their routers.

The discussion quickly deteriorated into you really need a provisioning system and in one of the responses Jared Mauch provided a link to a NANOG presentation by Shawn Morris from NTT.

read more see 7 comments

iOS uses Multipath TCP – Does It Matter?

When Apple launched the new release of iOS last autumn, networking gurus realized the new iOS uses MP-TCP, a recent development that allows a single TCP socket (as presented to the higher layers of the application stack) to use multiple parallel TCP sessions. Does that mean we’re getting closer to fixing the TCP/IP stack?

TL&DR summary: Unfortunately not.

read more see 6 comments
Sidebar