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Category Archives for "Networking"

CLI or API… Again (and Again and Again…)

Got this comment on one of my blog posts:

When looking at some of the CLIs just front-ending RESTAPIs, I wonder if "survival" of CLI isn't just in the eyes of the beholder.

It made me really sad because I wrote about this exact topic several times… obviously in vain. Or as one of my network automation friends said when I asked him to look at the draft of this blog post:

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Is my TPM affected by the Infineon disaster?

I made a tool to check if your TPM chip is bad. Well, it extracts the SRK public key and you can then use marcan’s tool to easily check if the key is good or bad.

Example use:

$ g++ -o check-srk -std=gnu++11 check-srk.cc -ltspi -lssl -lcrypto 2>&1 && ./check-srk
Size: 2048
Outputting modulus…
8490234823904890234823904823904890238490238490238490238490[…]893428490823904231
$ wget https://gist.githubusercontent.com/marcan/fc87aa78085c2b6f979aefc73fdc381f/raw/526bc2f2249a2e3f5d4450c7c412e0dbf57b2288/roca_test.py
[…]
$ python roca_test.py 8490234823904890234823904823904890238490238490238490238490[…]893428490823904231
Vuln!

(use -s if you have an SRK PIN)

If the SRK is weak then not only are very likely anything else you generated in the TPM weak, but also anything generated outside the TPM and imported is crackable, since your blobs are encrypted using this crackable SRK key.

How to Monkey-Patch the Linux Kernel

How to Monkey-Patch the Linux Kernel

I have a weird setup. I type in Dvorak. But, when I hold ctrl or alt, my keyboard reverts to Qwerty.

You see, the classic text-editing hotkeys, ctrl+Z, ctrl+X, ctrl+C, and ctrl+V are all located optimally for a Qwerty layout: next to the control key, easy to reach with your left hand while mousing with your right. In Dvorak, unfortunately, these hotkeys are scattered around mostly on the right half of the keyboard, making them much less convenient. Using Dvorak for typing but Qwerty for hotkeys turns out to be a nice compromise.

But, the only way I could find to make this work on Linux / X was to write a program that uses X "grabs" to intercept key events and rewrite them. That was mostly fine, until recently, when my machine, unannounced, updated to Wayland. Remarkably, I didn't even notice at first! But at some point, I realized my hotkeys weren't working right. You see, Wayland, unlike X, actually has some sensible security rules, and as a result, random programs can't just man-in-the-middle all keyboard events anymore. Which broke my setup.

Yes, that's right, I'm that guy:

How to Monkey-Patch the Linux Kernel

Source: xkcd 1172

So what was I to do? I began Continue reading

HPE gives up the battle for tier 1 data center customers

A few weeks back I told you how white box vendors, those Chinese-made, unbranded server vendors that compete with HP Enterprise and Dell EMC, were taking a sizable chunk of the business from the brand-name vendors.Well, now HPE has made it official and announced it will no longer try to sell commodity hardware — the cheap, low-end servers used in abundance in public-facing data centers — to tier 1 customers like Amazon, Facebook, Google and Microsoft. Also on Network World: How HPE plans to spin out its software assets HPE president Antonio Neri made the announcement at HPE’s analyst day event last week. He added that HPE would continue to sell higher-end servers to those vendors.To read this article in full or to leave a comment, please click here

HPE gives up the battle for tier 1 data center customers

A few weeks back I told you how white box vendors, those Chinese-made, unbranded server vendors that compete with HP Enterprise and Dell EMC, were taking a sizable chunk of the business from the brand-name vendors.Well, now HPE has made it official and announced it will no longer try to sell commodity hardware — the cheap, low-end servers used in abundance in public-facing data centers — to tier 1 customers like Amazon, Facebook, Google and Microsoft. Also on Network World: How HPE plans to spin out its software assets HPE president Antonio Neri made the announcement at HPE’s analyst day event last week. He added that HPE would continue to sell higher-end servers to those vendors.To read this article in full or to leave a comment, please click here

IDG Contributor Network: The 4 SD-WAN architectures for network security

SD-WAN might have begun as a networking technology, but the SD-WAN’s future lies in security. Integrating branch security features into SD-WAN, allow leaner, simpler remote office deployments.  To those ends, security vendors have introduced SD-WAN capabilities — and SD-WAN vendors add security capabilities.1. SD-WAN appliances with basic firewalling Many SD-WAN vendors deliver basic firewalling capabilities in their SD-WAN appliances. These firewalls are roughly equivalent to the stateful firewalls you might see in a branch office router. Capabilities will include policy-based filtering and blocking applications based on port or IP addresses. Examples include Cisco (Viptela), Silver Peak and Velocloud.To read this article in full or to leave a comment, please click here

Think Of Your Audience

One of the challenges technical authors face is that of peer respect. That is, technical people who took a lot of time to learn what they know want to be respected by their peers when they write. They want to be recognized for their knowledge, wisdom, and insights.

In that context, there’s often fear before pressing “Publish.” Was every detail correct? Was every scenario considered? Was the very latest information about a topic included?

The fear of hitting publish is well-founded for technical authors, because technical folks have a way of being nit-picky, pedantic, and annoying. One small detail wrong, one badly stated premise, and the angry comment and critical tweet claws come out, slashing at your ego.

Will they like me? I just want everyone to like me.

One solution, of course, is to have a thick skin. If you view criticisms as a way to improve a piece, that’s the best route to go, especially when the commenter has a good point. Being able to ignore critics is another useful skill, because there are plenty of folks who say a lot while adding no value whatsoever.

However, I think the most important point to keep in mind Continue reading

Think Of Your Audience

One of the challenges technical authors face is that of peer respect. That is, technical people who took a lot of time to learn what they know want to be respected by their peers when they write. They want to be recognized for their knowledge, wisdom, and insights.

In that context, there’s often fear before pressing “Publish.” Was every detail correct? Was every scenario considered? Was the very latest information about a topic included?

The fear of hitting publish is well-founded for technical authors, because technical folks have a way of being nit-picky, pedantic, and annoying. One small detail wrong, one badly stated premise, and the angry comment and critical tweet claws come out, slashing at your ego.

Will they like me? I just want everyone to like me.

One solution, of course, is to have a thick skin. If you view criticisms as a way to improve a piece, that’s the best route to go, especially when the commenter has a good point. Being able to ignore critics is another useful skill, because there are plenty of folks who say a lot while adding no value whatsoever.

However, I think the most important point to keep in mind Continue reading

BGPsec and Reality

From time to time, someone publishes a new blog post lauding the wonderfulness of BGPsec, such as this one over at the Internet Society. In return, I sometimes feel like I am a broken record discussing the problems with the basic idea of BGPsec—while it can solve some problems, it creates a lot of new ones. Overall, BGPsec, as defined by the IETF Secure Interdomain (SIDR) working group is a “bad idea,” a classic study in the power of unintended consequences, and the fond hope that more processing power can solve everything. To begin, a quick review of the operation of BGPsec might be in order. Essentially, each AS in the AS Path signs the “BGP update” as it passes through the internetwork, as shown below.

In this diagram, assume AS65000 is originating some route at A, and advertising it to AS65001 and AS65002 at B and C. At B, the route is advertised with a cryptographic signature “covering” the first two hops in the AS Path, AS65000 and AS65001. At C, the route is advertised with a cryptogrphic signature “covering” the first two hops in the AS Path, AS65000 and AS65002. When F advertises this route to H, at Continue reading

History of computers, part 2 — TCP/IP owes a lot to Xerox PUP

To understand where we are going, we first must understand where we have been. This applies equally well to the history of nations across the globe as it does to computers and computer networking.With that in mind, we’re taking a slow (somewhat meandering) stroll through the history of how computers talk to each other. Last time, we talked a bit about dial-up Bulletin Board Systems (BBSs) – popular through the 1980s and the bulk of the 1990s.Also on Network World: The hidden cause of slow Internet and how to fix it Today, I’d like to talk about one of the most influential, but rarely discussed, networking protocol suites: PARC Universal Packet (PUP).To read this article in full or to leave a comment, please click here

History of computers, part 2 — TCP/IP owes a lot to Xerox PUP

To understand where we are going, we first must understand where we have been. This applies equally well to the history of nations across the globe as it does to computers and computer networking.With that in mind, we’re taking a slow (somewhat meandering) stroll through the history of how computers talk to each other. Last time, we talked a bit about dial-up Bulletin Board Systems (BBSs) – popular through the 1980s and the bulk of the 1990s.Also on Network World: The hidden cause of slow Internet and how to fix it Today, I’d like to talk about one of the most influential, but rarely discussed, networking protocol suites: PARC Universal Packet (PUP).To read this article in full or to leave a comment, please click here

IBM casts Watson as the brains behind IoT

IBM is trying to be the brains behind the increasingly brawny presence of IoT in all corners of the business world, using its AI expertise to offer insight into piles of new data, provision new implementations, and help drive decision-making.The company thinks that its Watson AI is the ideal back-end for IoT, which is an area that few companies are addressing so directly. There’s a great deal of uptake around technology that connects new devices to the network, but comparatively little that actually does meaningful work on the floods of new data provided as a consequence.+ALSO ON NETWORK WORLD: REVIEW: Turbonomic, VMware virtualization management tools + Cisco snaps up streaming-data startup PerspicaTo read this article in full or to leave a comment, please click here