Wipebook – A Portable Whiteboard

It is a stereotype, but engineers really do like whiteboards. Problem is, you can’t carry one around with you. Plus there’s still a few unenlightened employers who don’t provide whiteboards. Enter the Wipebook, a spiral-bound notebook made of whiteboard-like pages: I normally carry a notebook for scratching out notes while talking to customers, sketching diagrams, […]

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iRules/Tcl – Watch the Comments

It’s pretty common practice to ‘comment out’ lines in scripts. The code stays in place, but doesn’t get executed. Perfect for testing, when you might need more debug output, or you want to run a slightly different set of actions. But you have to be careful when commenting out lines – it might catch you out, and […]

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Complexity vs Security

Many of the ‘security’ measures in our networks add complexity. That may be an acceptable tradeoff, if we make a meaningful difference to security. But often it feels like we just add complexity for no real benefit. Here’s some examples of what I’m talking about: Multiple Firewall Layers: Many networks use multiple layers of firewalls. If […]

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War Stories: Cursed VLANs

I’ve written before about switch ports being permanently disabled. This time it’s something new to me: VLANs that refuse to forward frames. A Simple Network The network was pretty straightforward. A pair of firewalls connecting through a pair of switches to a pair of routers: Sub-interfaces were used on the routers and firewalls, with trunks […]

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Ops Work vs Project Work

There’s a constant tension between delivering new services, and running the existing services well. How do you figure out how to prioritise work between Operations tasks and Project work? Skewing too far either way leads to problems. Maybe the answer is in how we structure Operations tasks? Definitions Operations work: Dealing with outages, trouble tickets, support requests, […]

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Meeting Rules

Years ago a wise engineer gave me these rules for meetings: Never go into a meeting unless you know what the outcome will be. Plan to leave the meeting with less work than when you went in. Stick to those rules, and you’ll do well. OK, so maybe the second rule’s not so serious, but […]

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Cumulus in the Campus?

Recently I’ve been idly speculating about how campus networking could be shaken up, with different cost and management models. A few recent podcasts have inspired some thoughts on how Cumulus Networks might fit into this. In response to a PacketPushers podcast on HP Network Management, featuring yours truly, Kanat asks: For me the benchmark of network management so […]

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Accurate Dependency Mapping – One Day?

Recently I’ve been thinking about Root Cause Analysis (RCA), and how it’s not perfect, but there may be hope for the future. The challenge is that Automated RCA needs an accurate, complete picture of how everything connects together to work well. You need to know all the dependencies between networks, storage, servers, applications, etc. If you […]

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Fixed-Price, or T&M?

Recently I posted about Rewarding Effort vs Results, how different contract structures can have different outcomes. This post covers Time & Materials vs Fixed-Price a little more, looking at pros & cons, and where each one is better suited. Definitions: Time & Materials: Client & supplier agree on the requirements, and an hourly rate. The client is billed […]

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Andrisoft Wanguard: Cost-Effective Network Visibility

Andrisoft Wansight and Wanguard are tools for network traffic monitoring, visibility, anomaly detection and response. I’ve used them, and think that they do a good job, for a reasonable price. Wanguard Overview There are two flavours to what Andrisoft does: Wansight for network traffic monitoring, and Wanguard for monitoring and response. They both use the […]

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