If you are getting this message appearing repeatedly on a Juniper switch (e.g. an EX4300), check you don’t have an IRB interface that is not attached to a VLAN. Alternatively, check your IRBs all have IP addresses.
Remember my rants about VMware and firewall vendors promoting crazy solutions that work best in PowerPoint and cause more headaches than anything else (excluding increased vendor margins and sales team bonuses, of course)?
Here’s another we-don’t-need-all-that-complexity real-life story coming from one of my long-term subscribers:
Watchman: monitoring dependency conflicts for Python library ecosystem Wang et al., ICSE ‘20
There are more than 1.4M Python libraries in the PyPI repository. Figuring out which combinations of those work well together is not always easy. In fact, we have a phrase for navigating the maze of dependencies modern projects seem to accumulate: “dependency hell”. It’s often not the direct dependencies of your project that bite you, but the dependencies of your dependencies, all the way on down to transitive closure. In today’s paper from ICSE ‘20, Wang et al. study the prevalence of dependency conflicts in Python projects and their causes. Having demonstrated (not that many of us would need much convincing) that dependency conflicts are a real problem, they build and evaluate Watchman, a tool to quickly find and report dependency conflicts, and to predict dependency conflicts in the making. Jolly useful it looks too.
If you have a set of versioned dependencies that all work together, you can create a lock file to pin those versions. But if you haven’t yet reached that happy place, or you need to upgrade, add or remove a dependency, you’ll be Continue reading
If you’re like me, you’re probably sick-and-tired of Python versions, environments… Every time I update Python on my MacBook Pro with Homebrew, I lose all packages I installed for the previous version of Python (because I’m installing them system-wide and they’re stored in version-specific directory).
Jon Langemak found a potential solution to this problem: PyEnv. My first reaction was: Great, just what I need… but as he described how it really works, I realized that it’s always possible to add another layer of indirection. RFC1925 strikes again.
Keepalived is a Linux implementation of VRRP. The usual role of VRRP is to share a virtual IP across a set of routers. For each VRRP instance, a leader is elected and gets to serve the IP address, ensuring the high availability of the attached service. Keepalived can also be used for a generic leader election, thanks to its ability to use scripts for healthchecking and run commands on state change.
A simple configuration looks like this:
vrrp_instance gateway1 { state BACKUP # ❶ interface eth0 # ❷ virtual_router_id 12 # ❸ priority 101 # ❹ virtual_ipaddress { 2001:db8:ff/64 } }
The state keyword in ❶ instructs Keepalived to not take the leader
role when starting. Otherwise, incoming nodes create a temporary
disruption by taking over the IP address until the election settles.
The interface keyword in ❷ defines the interface for sending and
receiving VRRP packets. It is also the default interface to configure
the virtual IP address. The virtual_router_id directive in ❸ is
common to all nodes sharing the virtual IP. The priority keyword in
❹ helps choosing which router will be elected as leader. If you need
more information around Keepalived, be sure to check Continue reading
The netbox.netbox collection from Ansible Galaxy
provides several modules to update NetBox objects:
- name: create a device in NetBox netbox_device: netbox_url: http://netbox.local netbox_token: s3cret data: name: to3-p14.sfo1.example.com device_type: QFX5110-48S device_role: Compute Switch site: SFO1
However, if NetBox is not your source of truth, you may want to ensure it stays in sync with your configuration management database1 by removing outdated devices or IP addresses. While it should be possible to glue together a playbook with a query, a loop and some filtering to delete unwanted elements, it feels clunky, inefficient and an abuse of YAML as a programming language. A specific Ansible module solves this issue and is likely more flexible.
Notice
I recommend that you read “Writing a custom Ansible module” as an introduction, as well as “Syncing MySQL tables” for a first simpler example.
The module has the following signature and it syncs NetBox with the content of the provided YAML file:
netbox_sync: source: netbox.yaml api: https://netbox.example.com token: s3cret
The synchronized objects are:
One thing I’ve found out over the past decade of writing is that some problems are easy enough to solve that we sometimes forget about them. Maybe it’s something you encounter once in a great while. Perhaps it’s something that needed a little extra thought or a novel reconfiguration of an existing solution. Something so minor that you didn’t even think to write it down. Until you run into the problem again.
The truth behind most of these simple problems is that the solutions aren’t always apparent. Sure, you might be a genius when it comes to fixing the network or the storage array. Maybe you figured out how to install some new software to do a thing in a way that wasn’t intended. But did you write any of it down for later use? Did you make sure to record what you’ve done so someone else can use it for reference?
Part of the reason why I started blogging was to have those written solutions to problems I couldn’t find a quick answer to. What it became was way more than I had originally intended. But the posts that I write that still get the most attention aren’t my Continue reading
In Europe and beyond we struggle with effective policing of online communications. As generations before, we want to be both: free and safe when we interact with others, go shopping or get our news. While this balance is difficult, it is possible to achieve: the rapid development of online communications, often proclaimed the wild west of modern society, Continue reading
One of the weekend reads collected by Russ White contained a pointer to a hilarious description of blockchain - a solution in search of a problem. Here are a few quotes to get you started (and I had a really hard time selecting just a few):
I’ve never seen so much bloated bombast fall so flat on closer inspection.
At its core, blockchain is a glorified spreadsheet.
The only thing is that there’s a huge gap between promise and reality. It seems that blockchain sounds best in a PowerPoint slide.
Someone should use that article as a framework and replace blockchain with OpenFlow or SDN ;)
In today's sponsored show, we talk with Sinefa about its Digital Experience Monitoring capabilities. Sinefa assembles network traffic, DPI, end point monitoring, and synthetic transactions to get clear, actionable information on network performance to measure end user experience and improve troubleshooting. Our guests are Chris Siakos, CTO; and Alex Henthorn-Iwane, VP of Product Marketing.
The post Heavy Networking 540: Sinefa Blends Network Data, Synthetics To Measure End User Experience (Sponsored) appeared first on Packet Pushers.
Earlier this year, as part of the European Digital Strategy, the European Commission announced a Digital Services Act package to develop new and revised rules to harmonize and deepen the Single Market for digital services. As a part of that initiative, it also initiated a public consultation to scope the specific issues that may require regulatory intervention.
The Internet Society submitted recommendations in response to the critical issues raised in this consultation. One of the key considerations that we hope comes across in this submission is that in order “to design better regulation for the Internet, it is important to understand two things: the first one is that today’s Internet, despite how much it has evolved, still continues to depend on its original architecture; and, the second relates to how preserving this design is important for drafting regulation that is fit for purpose.”
As noted by the Commission, the scale of digital services is substantially different from 20 years ago, when the E-Commerce Directive was introduced. New actors and new services have emerged, creating a much more complex ecosystem. This new ecosystem presents new challenges, particularly with regard to illegal and harmful activities and content online. Current discussions and regulatory initiatives Continue reading
Hey, it's HighScalability time!
I can't wait for the duel. Just don't shoot into the air.
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Know someone who could benefit from becoming one with the cloud? Of course you do. I wrote Explain the Cloud Like I'm 10 just for them. On Amazon it has 167 mostly 5 star reviews. Here's a 100% lectin-free review:
