Random Thoughts on IoT

26 October 2020 |

Let’s play the analogy game. The Internet of Things (IoT) is probably going end up being like … a box of chocolates, because you never do know what you are going to get? a big bowl of spaghetti with a serious lack of meatballs? Whatever it is, the IoT should have network folks worried about security. There is, of course, the problem of IoT devices being attached to random places on the network, exfiltrating personal data back to a cloud server you don’t know anything about. Some of these devices might be rogue, of course, such as Raspberry Pi attached to some random place in the network. Others might be more conventional, such as those new exercise machines the company just brought into the gym that’s sending personal information in the clear to an outside service.

Technologies that Didn’t: Network Operating Systems

20 October 2020 |

For those with a long memory—no, even longer than that—there were once things called Network Operating Systems (NOS’s). These were not the kinds of NOS’s we have today, like Cisco IOS Software, or Arista EOS, or even SONiC. Rather, these were designed for servers. The most common example was Novell’s Netware. These operating systems were the “bread and butter” of the networking world for many years. I was a Certified Netware Expert (CNE) version 4.0, and then 4.11, before I moved into the routing and switching world. I also deployed Banyan’s Vines, IBM’s OS/2, and a much simpler system called LANtastic, among others.

Hints and Principles: Applied to Networks

19 October 2020 |

While software design is not the same as network design, there is enough overlap for network designers to learn from software designers. A recent paper published by Butler Lampson, updating a paper he wrote in 1983, is a perfect illustration of this principle. The paper is caleld Hints and Principles for Computer System Design. I’m not going to write a full review here–you should really go read the paper for yourself–but rather just point out some useful bits of the paper.

Underhanded Code and Automation

12 October 2020 | Comments Off on Underhanded Code and Automation

So, software is eating the world—and you thought this was going to make things simpler, right? If you haven’t found the tradeoffs, you haven’t looked hard enough. I should trademark that or something! 🙂 While a lot of folks are thinking about code quality and supply chain are common concerns, there are a lot of little “side trails” organizations do not tend to think about. One such was recently covered in a paper on underhanded code, which is code designed to pass a standard review which be used to harm the system later on.

Link State in DC Fabrics

8 October 2020 | Comments Off on Link State in DC Fabrics

If you don’t normally read IPJ, you should. Melchoir and I have an article up in the latest edition on link state in DC fabrics.

To make a case for linkstate protocols in DC fabric underlays, an extensive examination of the positive and negative aspects of BGP—and the other available protocols—is essential. Ultimately, it is up to individual operators to decide which protocol is “the best” for their application, a decision based on business and operational—as well as technical—reasons.

Read the whole thing here.

RFC1925 Rule 2

6 October 2020 | Comments Off on RFC1925 Rule 2

According to RFC1925, the second fundamental truth of networking is: No matter how hard you push and no matter what the priority, you can’t increase the speed of light.

Reducing Complexity through Interaction Surfaces

5 October 2020 | Comments Off on Reducing Complexity through Interaction Surfaces

A recent paper on network control and management (which includes Jennifer Rexford on the author list—anything with Jennifer on the author list is worth reading) proposes a clean slate 4d approach to solving much of the complexity we encounter in modern networks. While the paper is interesting, it’s very unlikely we will ever see a clean slate design like the one described, not least because there will always be differences between what the proper splits are—what should go where.

Random Thoughts

28 September 2020 | Comments Off on Random Thoughts

This week is very busy for me, so rather than writing a single long, post, I’m throwing together some things that have been sitting in my pile to write about for a long while.

From Dalton Sweeny:

A physicist loses half the value of their physics knowledge in just four years whereas an English professor would take over 25 years to lose half the value of the knowledge they had at the beginning of their career. . . Software engineers with a traditional computer science background learn things that never expire with age: data structures, algorithms, compilers, distributed systems, etc. But most of us don’t work with these concepts directly. Abstractions and frameworks are built on top of these well studied ideas so we don’t have to get into the nitty-gritty details on the job (at least most of the time).

Technologies that Didn’t: CLNS

22 September 2020 |

The Open Systems Interconnect (OSI) model is the most often taught model of data transmission—although it is not all that useful in terms of describing how modern networks work. What many engineers who have come into network engineering more recently do not know is there was an entire protocol suite that went with the OSI model. Each of the layers within the OSI model, in fact, had multiple protocols specified to fill the functions of that layer. For instance, X.25, while older than the OSI model, was adopted into the OSI suite to provide point-to-point connectivity over some specific kinds of physical circuits. Moving up the stack a little, there were several protocols that provided much the same service as the widely used Internet Protocol (IP).

Reducing RPKI Single Point of Takedown Risk

21 September 2020 | Comments Off on Reducing RPKI Single Point of Takedown Risk

The RPKI, for those who do not know, ties the origin AS to a prefix using a certificate (the Route Origin Authorization, or ROA) signed by a third party. The third party, in this case, is validating that the AS in the ROA is authorized to advertise the destination prefix in the ROA—if ROA’s were self-signed, the security would be no better than simply advertising the prefix in BGP. Who should be able to sign these ROAs? The assigning authority makes the most sense—the Regional Internet Registries (RIRs), since they (should) know which company owns which set of AS numbers and prefixes.

The general idea makes sense—you should not accept routes from “just anyone,” as they might be advertising the route for any number of reasons. An operator could advertise routes to source spam or phishing emails, or some government agency might advertise a route to redirect traffic, or block access to some web site. But … if you haven’t found the tradeoffs, you haven’t looked hard enough. Security, in particular, is replete with tradeoffs.