Ivan Pepelnjak

Author Archives: Ivan Pepelnjak

Case Study: Combine Physical and Virtual Appliances in a Private Cloud

Cloud builders are often using my ExpertExpress service to validate their designs. Tenant onboarding into a multi-tenant (private or public) cloud infrastructure is a common problem, and tenants frequently want to retain the existing network services appliances (firewalls and load balancers).

The Combine Physical and Virtual Appliances in a Private Cloud case study describes a typical solution that combines per-tenant virtual appliances with frontend physical appliances.

Video: IPv6 High Availability Components

Last spring I ran an IPv6 High Availability webinar which started (not surprisingly) with a simple question: “which network components affect availability in IPv6 world, and how is a dual-stack or an IPv6-only environment different from what we had in the IPv4 world?

This part of the webinar is now available on ipSpace.net content web site. Enjoy the video, explore other IPv6 resources on ipSpace net, and if you’re from Europe don’t forget to register for the IPv6 Security Summit @ Troppers in mid-March.

IPv6 Renumbering – Mission Impossible?

In one of the discussions on v6ops mailing list Matthew Petach wrote:

The probability of us figuring out how to scale the routing table to handle 40 billion prefixes is orders of magnitude more likely than solving the headaches associated with dynamic host renumbering. That ship has done gone and sailed, hit the proverbial iceberg, and is gathering barnacles at the bottom of the ocean.

Is it really that bad? Is simple renumbering in IPv6 world just another myth? It depends.

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vLAG Caveats in Brocade VCS Fabric

Brocade VCS fabric has one of the most flexible multichassis link aggregation group (LAG) implementation – you can terminate member links of an individual LAG on any four switches in the VCS fabric. Using that flexibility is not always a good idea.

2015-01-23: Added a few caveats on load distribution

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SDN Router @ Spotify on Software Gone Wild

Imagine you need a data center WAN edge router with multiple 10GE uplinks. You’d probably go for an ASR or a MX-series router, right? How about using a 2 Tbps ToR switch and an SDN solution to make it work with full Internet routing table?

If you happen to have iTunes on your computer, please spend 10 seconds rating the podcast before you start listening to it. Thank you!

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Pick a Topic for NSX Deep Dive Software Gone Wild Episode

Dmitri Kalintsev, one of the networking guys from VMware NSX team, has kindly agreed to do an NSX technical deep dive Software Gone Wild episode… and you have the opportunity to tell him what you’d like to hear. It’s as easy as writing a comment, and we’ll pick one of the most popular topics.

Do keep in mind that we plan to do a technical deep dive, and it has to fit within an hour or so or nobody will ever listen to it, so please keep your suggestions focused. “Troubleshooting NSX”, “NSX Design”, or “NSX versus ACI ” is not what we’re looking for ;)

Palo Alto Virtual Firewalls on Software Gone Wild

One of the interesting challenges in the Software-Defined Data Center world is the integration of network and security services with the compute infrastructure and network virtualization. Palo Alto claims to have tightly integrated their firewalls with VMware NSX and numerous cloud orchestration platforms - it was time to figure out how that’s done, so we decided to go on a field trip into the scary world of security.

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Latency: the Killer of Spread-Out Application Stack Ideas

A few months ago I described how bandwidth limitations shatter the dreams of spread-out application stacks with elements residing (or being dynamically migrated) between data centers. Today let’s focus on bandwidth’s ugly cousin: latency.

TL&DR Summary: Spreading the server components of an application across multiple locations (multiple data centers or hybrid cloud deployments) can easily result in dismal performance even when there’s plenty of bandwidth available.

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How Does MPLS-TE Interact with QoS

MPLS Traffic Engineer is sometimes promoted as a QoS solution (it seems bandwidth calendaring is a permanent obsession of some networking engineers, and OpenFlow is no more a solution than MPLS-TE was ;), but in reality it’s pretty hard to make the two work together seamlessly (just ask anyone who had to implement auto-bandwidth MPLS-TE in a large network).

Not surprisingly, we addressed the topic during our MPLS Tech Talk.