Duplicate ARP Replies with Anycast Gateways
A reader sent me the following intriguing question:
I’m trying to understand the ARP behavior with SVI interface configured with anycast gateways of leaf switches, and with distributed anycast gateways configured across the leaf nodes in VXLAN scenario.
Without going into too many details, the core dilemma is: will the ARP request get flooded, and will we get multiple ARP replies. As always, the correct answer is “it depends” 🤷‍♂️
Duplicate ARP Replies with Anycast Gateways
A reader sent me the following intriguing question:
I’m trying to understand the ARP behavior with SVI interface configured with anycast gateways of leaf switches, and with distributed anycast gateways configured across the leaf nodes in VXLAN scenario.
Without going into too many details, the core dilemma is: will the ARP request get flooded, and will we get multiple ARP replies. As always, the correct answer is “it depends” 🤷‍♂️
What Enterprises Can Expect as Carriers to Spend Billions on Broadband Rollouts
From funding to the front door, IT managers can learn from state-level fiber expansions and benefit from programs created to speed high-speed Internet buildouts powered by federal legislation, the FCC, and annual carrier capital expenditures.Optimizing Magic Firewall’s IP lists
Magic Firewall is Cloudflare’s replacement for network-level firewall hardware. It evaluates gigabits of traffic every second against user-defined rules that can include millions of IP addresses. Writing a firewall rule for each IP address is cumbersome and verbose, so we have been building out support for various IP lists in Magic Firewall—essentially named groups that make the rules easier to read and write. Some users want to reject packets based on our growing threat intelligence of bad actors, while others know the exact set of IPs they want to match, which Magic Firewall supports via the same API as Cloudflare’s WAF.
With all those IPs, the system was using more of our memory budget than we’d like. To understand why, we need to first peek behind the curtain of our magic.
Life inside a network namespace
Magic Transit and Magic WAN enable Cloudflare to route layer 3 traffic, and they are the front door for Magic Firewall. We have previously written about how Magic Transit uses network namespaces to route packets and isolate customer configuration. Magic Firewall operates inside these namespaces, using nftables as the primary implementation of packet filtering.
When a user makes an API request to configure their Continue reading
Understanding Data Center Fabrics 09: Other Considerations – Video
In the final video of this series on data center fabrics, Russ White walks through a set of considerations you might want to ponder as you design your data center fabric. These considerations include whether to single-home or dual-home a server in a fabric (it depends!), why Russ isn’t a fan of MLAGs in a […]
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Can Fantastical Openings Replace Calendly?
TL;DR
Fantastical Openings can’t replace Calendly for my scheduling needs yet, but it’s close.
The Rest Of The Story
I use Calendly so that folks can schedule me for appointments. I send people a Calendly link, and they choose an available time slot. Calendly creates calendar invitations and sends them to me and the requestor. Calendly also integrates with Zoom, so that an invite comes with a Zoom meeting already attached.
In my years of Calendly use, I’ve found it to be…
- Reliable. It just works.
- Flexible. The availability rules engine allows me to configure conditions such as “leave a gap of X minutes between appointments” that I rely on to keep my calendar sane.
- Expensive. $144/year for the features I need.
I also use Fantastical by Flexibits. In my few months as a Fantastical user, I’ve found it to be…
- Beautiful. It’s the best calendaring interface of anything I’ve tried.
- Integrated. I use Fantastical to integrate with multiple calendars, Zoom, and the Todoist task manager. I use Fantastical both on my Mac and iOS devices.
- A super power. Fantastical happens to be highly compatible with how I work. I am more productive with Fantastical.
- Affordable. $40/year for the features Continue reading
CVE-2022-1096: How Cloudflare Zero Trust provides protection from zero day browser vulnerabilities
On Friday, March 25, 2022, Google published an emergency security update for all Chromium-based web browsers to patch a high severity vulnerability (CVE-2022-1096). At the time of writing, the specifics of the vulnerability are restricted until the majority of users have patched their local browsers.
It is important everyone takes a moment to update their local web browser. It’s one quick and easy action everyone can contribute to the cybersecurity posture of their team.
Even if everyone updated their browser straight away, this remains a reactive measure to a threat that existed before the update was available. Let’s explore how Cloudflare takes a proactive approach by mitigating the impact of zero day browser threats with our zero trust and remote browser isolation services. Cloudflare’s remote browser isolation service is built from the ground up to protect against zero day threats, and all remote browsers on our global network have already been patched.
How Cloudflare Zero Trust protects against browser zero day threats
Cloudflare Zero Trust applies a layered defense strategy to protect users from zero day threats while browsing the Internet:
- Cloudflare’s roaming client steers Internet traffic over an encrypted tunnel to a nearby Cloudflare data center for inspection and Continue reading
The New Edge as a Service
As we enter 2022, there is much discussion on the “post-pandemic” world of campus and how it’s changing. Undoubtedly, the legacy 2000 era campus was mired in complexity, with proprietary features, siloed designs, and fragile software ripe for change. This oversubscribed campus is riddled with challenges, including critical outages causing risk-adverse behaviors and labor-intensive roll-outs hampering improvements. The future of the campus has changed as the lines between corporate headquarters, home, remote and transit workers are blurring and creating distributed workspaces. Before the pandemic, the most common network designs were rigidly hierarchical. They were based upon a manual model developed in the mid-1990s. As the demand for scale increased, the end user experience was degraded and the cost per connected host continued to escalate.
Are we ready to evolve the legacy campus to a new cognitive edge for the new and dispersed class of users, devices and IoT/OT? I think so and the time to recalibrate and redesign the campus is now!
How the Oscars impacted the Internet (at least in the US)
The 94th Academy Awards happened this past Sunday, March 27, 2022. In the global event we got to see several Oscars attributed to winners like CODA, Jane Campion (the director of The Power of the Dog) and also Dune (which won six Oscars), but also moments that had a clear impact in the Internet traffic, like the altercation on stage between Will Smith and Chris Rock.
Cloudflare Radar uses a variety of sources to provide aggregate information about Internet traffic and attack trends. In this blog post, we will use DNS name resolution data as a proxy for traffic to Internet services, as we did for the Super Bowl LVI.
The baseline value for the charts (that are only focused on the US) was calculated by taking the mean DNS traffic level for the associated Internet services between 08:00 - 12:00 PST on Sunday (March 27, 2022) — usually we use UTC, but we chose to use Los Angeles time as that’s where the event took place.
The event started with Beyoncé singing at 17:00 PST and ended at around 20:30. In terms of growth in traffic, the start of the show didn’t show much for social media, although TikTok Continue reading
BGP Labeled Unicast on Arista EOS
A week ago I described how Cisco IOS implemented BGP Labeled Unicast. In this blog post we’ll focus on Arista EOS using the same lab as before:
BGP sessions in the BGP-LU lab
BGP Labeled Unicast on Arista EOS
A week ago I described how Cisco IOS implemented BGP Labeled Unicast. In this blog post we’ll focus on Arista EOS using the same lab as before:
BGP sessions in the BGP-LU lab
IETF 113 – IEPG Meeting
The IEPG meets on the Sunday at the start of the IETF week. If there is a theme for the diverse collection of presentations here it is perhaps a focus on operational topics, but the particular selection of subjects in these sessions can be quite diverse.IETF 113 – DNS Topics
The IETF met in a hybrid format in March 2022. Here are my impressions from the DNS-related Working Group sessions during the week.Tech Bytes: Achieve SD-WAN Multicloud With Palo Alto Networks And Azure (Sponsored)
Today on the Tech Bytes podcast we’re sponsored by Palo Alto Networks, which is expanding its cloud partnership by integrating with Azure to help customers achieve a multicloud strategy.
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