Delivering HTTP/2 upload speed improvements

Cloudflare recently shipped improved upload speeds across our network for clients using HTTP/2. This post describes our journey from troubleshooting an issue to fixing it and delivering faster upload speeds to the global Internet.

We launched speed.cloudflare.com in May 2020 to give our users insight into how well their networks perform. The test provides download, upload and latency tests. Soon after release, we received reports from a small number of users that sometimes upload speeds were underreported. Our investigation determined that it seemed to happen with end users that had high upload bandwidth available (several hundreds Mbps class cable modem or fiber service). Our speed tests are performed via browser JavaScript, and most browsers use HTTP/2 by default. We found that HTTP/2 upload speeds were sometimes much slower than HTTP/1.1 (assuming all TLS) when the user had high available upload bandwidth.

Upload speed is more important than ever, especially for people using home broadband connections. As many people have been forced to work from home they’re using their broadband connections differently than before. Prior to the pandemic broadband traffic was very asymmetric (you downloaded way more than you uploaded… think listening to music, or streaming a movie), Continue reading

5G spectrum auctions expected in 2021 after Pentagon gives up frequencies

The U.S. Department of Defense will turn over some of its 5G frequency spectrum in a bid to help U.S. carriers bring commercial 5G services to market faster. 5G resources What is 5G? Fast wireless technology for enterprises and phones Private 5G can solve some problems that Wi-Fi can’t Private 5G keeps Whirlpool driverless vehicles rolling 5G can make for cost-effective private backhaul CBRS can bring private 5G to enterprises The DoD controls large portions of the mid-band 5G spectrum in the 3 GHz to 6 GHz range, which is used for military radar. Earlier this year, the White House and DoD formed "America's Mid-Band Initiative Team," or AMBIT, with the goal of making a contiguous, 100 MHz segment of mid-band spectrum available for use in 5G development by the end of the summer.To read this article in full, please click here

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MUST READ: What I’ve learned about scaling OSPF in Datacenters

Justin Pietsch published a fantastic recap of his experience running OSPF in AWS infrastructure. You MUST read what he wrote, here’s the TL&DR summary:

• Contrary to popular myths, OSPF works well on very large leaf-and-spine networks.
• OSPF nuances are really hard to grasp intuitively, and the only way to know what will happen is to run tests with the same codebase you plan to use in production environment.

Dinesh Dutt made similar claims on one of our podcasts, and I wrote numerous blog posts on the same topic. Not that anyone would care or listen, it’s so much better to watch vendor slide decks full of latest unicorn dust… but in the end, it’s usually not the protocol that’s broken, but the network design.

The Making of an RFC in today’s IETF

Zero-Touch Provisioning for Cisco IOS

The official documentation to automatically upgrade and configure on first boot a Cisco switch running on IOS, like a Cisco Catalyst 2960-X Series switch, is scarce on details. This note explains how to configure the ISC DHCP Server for this purpose.

When booting for the first time, Cisco IOS sends a DHCP request on all ports:

Dynamic Host Configuration Protocol (Discover)
    Message type: Boot Request (1)
    Hardware type: Ethernet (0x01)
    Hardware address length: 6
    Hops: 0
    Transaction ID: 0x0000117c
    Seconds elapsed: 0
    Bootp flags: 0x8000, Broadcast flag (Broadcast)
    Client IP address: 0.0.0.0
    Your (client) IP address: 0.0.0.0
    Next server IP address: 0.0.0.0
    Relay agent IP address: 0.0.0.0
    Client MAC address: Cisco_6c:12:c0 (b4:14:89:6c:12:c0)
    Client hardware address padding: 00000000000000000000
    Server host name not given
    Boot file name not given
    Magic cookie: DHCP
    Option: (53) DHCP Message Type (Discover)
    Option: (57) Maximum DHCP Message Size
    Option: (61) Client identifier
        Length: 25
        Type: 0
        Client Identifier: cisco-b414.896c.12c0-Vl1
    Option: (55) Parameter Request List
        Length: 12
        Parameter Request List Item: (1) Subnet Mask
        Parameter Request List Item: (66) TFTP Server Name
        Parameter Request List Item: (6) Domain Name Server
        Parameter Request List Item:  Continue reading

CEX (Code EXpress) 13. Creating your own Python modules.

Hello my friend,

Recently we have learned how to use the external modules to make your Python’s code more powerful. At some point, perhaps already now, you started creating user-defined functions so good that you would like to re-use them in other projects.

Automate all the things

Network automation is one of the most important things named by CIOs in Gather’s research. As such, the companies are (and will be) looking for the experts, who are able to develop new solutions and find creative ways to improve networks’ efficiency via automation. And we are keen to help you with that?

At our network automation training, either self-paced or instructor lead, you will learn the leading technologies, protocols, and tools used to manage the networks in the busiest networks worldwide, such as Google data centres. However, once you master all the skills, you will be able to automate the network of any scale. You will see the opportunities and you will exploit them.

Secret words: NETCONF, REST API, gRPC, JSON , XML, Protocol buffers, SSH, OpenConfig, Python, Ansible, Linux, Docker; and many other wonderful tools and techniques are waiting for you in our training!

Don’t miss opportunity to start your network Continue reading

The Local Maxima Ascension Of Datacenter At Nvidia

When we said thirteen weeks ago that we thought that Nvidia’s datacenter business would be its largest operating division before too long, we didn’t think it would only take a quarter to do that. …

The Local Maxima Ascension Of Datacenter At Nvidia was written by Timothy Prickett Morgan at The Next Platform.

Heavy Networking 536: Arrcus Reimagines The Chassis Router With Its Virtualized Distributed Router (Sponsored)

Heavy Networking 536: Arrcus Reimagines The Chassis Router With Its Virtualized Distributed Router (Sponsored)

Today's Heavy Networking dives into sponsor Arrcus's Virtualized Distributed Router, new software that transforms the monolithic chassis that can scale to thousands of ports while being operated and managed like a single device. Our guests are Murali Gandluru, Keyur Patel, and Nalin Pai from Arrcus.

The post Heavy Networking 536: Arrcus Reimagines The Chassis Router With Its Virtualized Distributed Router (Sponsored) appeared first on Packet Pushers.

Cisco open-source code boosts performance of Kubernetes apps over SD-WAN

Cisco has introduced an open-source project that it says could go a long way toward reducing the manual work involved in optimizing performance of Kubernetes-applications across SD-WANs.Cisco said it launched the Cloud-Native SD-WAN (CN-WAN) project to show how Kubernetes applications can be automatically mapped to SD-WAN with the result that the applications perform better over the WAN.More about SD-WAN: How to buy SD-WAN technology: Key questions to consider when selecting a supplier • How to pick an off-site data-backup method •  SD-Branch: What it is and why you’ll need it • What are the options for security SD-WAN? “In many cases, enterprises deploy an SD-WAN to connect a Kubernetes cluster with users or workloads that consume cloud-native applications. In a typical enterprise, NetOps teams leverage their network expertise to program SD-WAN policies to optimize general connectivity to the Kubernetes hosted applications, with the goal to reduce latency, reduce packet loss, etc.” wrote John Apostolopoulos, vice president and CTO of Cisco’s intent-based networking group in a group blog.To read this article in full, please click here

Opening Up Remote Access with Opengear

The Opengear OM2200

If you had told me last year at this time that remote management of devices would be a huge thing in 2020 I might have agreed but laughed quietly. We were traveling down the path of simultaneously removing hardware from our organizations and deploying IoT devices that could be managed easily from the cloud. We didn’t need to access stuff like we did in the past. Even if we did, it was easy to just SSH or console into the system from a jump box inside the corporate firewall. After all, who wants to work on something when you’re not in the office?

Um, yeah. Surprise, surprise.

Turns out 2020 is the Year of Having Our Hair Lit On Fire. Which is a catchy song someone should record. But it’s also the year where we have learned how to stand up 100% Work From Home VPN setups within a week, deploy architecture to the cloud and refactor on the fly to help employees stay productive, and institute massive change freezes in the corporate data center because no one can drive in to do a reboot if someone forgets to do commit confirmed or reload in 5.

Remote Continue reading

Weekend Reads 082120

When a zero-day vulnerability is exploited in the wild, it’s essential to identify the bug at the root of the attack. This “root cause analysis” informs researchers how an attack unfolded.

The House Judiciary chairman was closing in on his Perry Mason moment with Facebook CEO Mark Zuckerberg. Fortified with “hot” internal company documents, Rep. Jerrold Nadler was building his case at a hearing that seemed almost like a trial for Facebook and three other tech giants over alleged anti-competitive tactics.

While it’s true consumers have largely moved on, data centers are still looking for higher capacity hard drives. That’s why Western Digital (WD) developed new enterprise drives, which are packing what the company calls “ePMR” (energy-assisted perpendicular magnetic recording). For simplicity’s sake, we’ll stick with energy-assisted magnetic recording (EAMR).

Respondents to Tripwire’s survey revealed that they’re specifically worried about their employers’ cloud security. Indeed, 37% of participants indicated that risk management capabilities in the cloud were at least somewhat worse in the cloud than in other parts of the organization’s infrastructure.

In our previous blog about IcedID, we explored some of the changes in the malware and how it tries to evade detection. We also detailed how threat actors Continue reading

JUNOS | Filter-Based Forwarding

Alright, so Filter-Based Forwarding is nothing new. The technology has been around for a while and is relatively well documented. However, I wanted to share a specific use case where Filter-Based Forwarding can be extremely useful. In this scenario, we’re going to use Filter-Based Forwarding to forward traffic to a dedicated VRF where it is then pushed through a DDOS appliance and back to the router via a different VRF.

This construct is very useful when you only need to pass specific ingress traffic through the DDOS appliance. For example, customer destination prefixes who are paying for a DDOS service. Or traffic from certain source prefixes that are known to be malicious. Return traffic in either scenario is not passed via the appliance and is routed directly back to the source.

Challenge Statement
Specific ingress traffic received from transit & peering providers, via the TRANSIT VRF, must be pushed to the DIRTY VRF. The traffic must then be forwarded back towards the TRANSIT VRF via an appliance for inspection. Once the traffic is received back into the TRANSIT VRF it is onward routed as normal.

Solution
The solution involves defining the prefixes that should be considered within the Filter-Based Forwarding Continue reading

Alibaba On The Bleeding Edge Of RISC-V With XT910

It was just over a year ago that the RISC-V Foundation, the group shepherding the chip architecture in what over the past decade has become an active and crowded processor market, ratified the base instruction set architecture (ISA) and related specifications. …

Alibaba On The Bleeding Edge Of RISC-V With XT910 was written by Jeffrey Burt at The Next Platform.

Mapping Intermediary Liability in Latin America

Thanks to our Chapters in Latin America, we now have a clearer map of the intermediary liability regulatory landscape across the region.

Intermediary liability answers the question, “Should Internet intermediaries (ISPs, web hosting and cloud services, social media platforms, etc.)  be liable for content posted or for actions performed by others, such as, for example, their users?”

The success of the Internet depends on intermediary liability regimes that protect Internet providers – by ensuring responsibility for user behavior is on the users themselves, not on the intermediaries upon which they rely (both at the infrastructure and content layers).

The way legal frameworks deal with intermediary liability around the world can impact the Internet way of networking in different ways.

In some countries, intermediary liability legislation is well known: the 1996 US Communications Decency Act (Section 230) and the Brazilian Internet Bill of Rights, for example. But in much of the world it is covered by other more general-purpose regulations, such as tort law, consumer protection law, and child protection law.

We asked our local community to help us map and monitor the current regimes that apply to Internet intermediaries in their countries, so that our work can Continue reading

Technology Short Take 130

Welcome to Technology Short Take #130! I’ve had this blog post sitting in my Drafts folder waiting to be published for almost a month, and I kept forgetting to actually make it live. Sorry! So, here it is—better late than never, right?

Networking

• Here’s a walkthrough on using DNS over TLS on Fedora.
• Some Twitter followers recently pointed out gnmic, a gNMI CLI client. gNMI, by the way, stands for gRPC Network Management Interface (more information on gNMI can be found here). I haven’t used gnmic, but it certainly looks like an extremely useful tool.

Security

• Everyone’s favorite three-letter agency recently released some VPN security guidance, as reported by this InfoSecurity Magazine article. The article also provides some links to said guidance, for those that are interested.
• Matt Hamilton takes a closer look at a recent security vulnerability in the Harbor container registry. This vulnerability, known as a Server-Side Request Forgery, allowed Harbor project owners to scan the TCP ports of hosts on the Harbor server’s internal network.
• Ivan Pepelnjak discusses the security implications of so-called “Smart NICs.”
• Want to use a Yubikey to automatically lock and unlock your Linux system? See here.

Cloud Computing/Cloud Management

• Continue reading

Working Collaboratively to Improve Emerging Network Time Security Implementations

Accurate and secure time is essential for the security and trustworthiness of the Internet. Many systems that we regularly interact with rely on accurate time to function properly. Accurate time also provides an essential foundation for online security, and many security mechanisms, such as digital certificates used for Transport Layer Security (TLS), depend on accurate timekeeping. The Network Time Protocol (NTP) provides time synchronization for clocks on computer networks.

NTP’s security mechanisms were designed back in an era when most Internet traffic was trusted, and the risk of attack was unlikely. Due to the continued exponential expansion of the Internet, these mechanisms became outdated and needed to be redesigned. The Internet Engineering Task Force (IETF) has been working on a specification for Network Time Security (NTS) for several years now. This specification was approved by the Internet Engineering Steering Group (IESG) in March of this year and is currently in the RFC editing process for the final publication. Over the course of the last couple of years, there have been a series of NTS projects held as part of the IETF Hackathons. These projects have worked to identify mistakes and ambiguities in the specification and to test and improve interoperability Continue reading

How Cloudflare uses Cloudflare Spectrum: A look into an intern’s project at Cloudflare

Cloudflare extensively uses its own products internally in a process known as dogfooding. As part of my onboarding as an intern on the Spectrum (a layer 4 reverse proxy) team, I learned that many internal services dogfood Spectrum, as they are exposed to the Internet and benefit from layer 4 DDoS protection. One of my first tasks was to update the configuration for an internal service that was using Spectrum. The configuration was managed in Salt (used for configuration management at Cloudflare), which was not particularly user-friendly, and required an engineer on the Spectrum team to handle updating it manually.

This process took about a week. That should instantly raise some questions, as a typical Spectrum customer can create a new Spectrum app in under a minute through Cloudflare Dashboard. So why couldn’t I?

This question formed the basis of my intern project for the summer.

The Process

Cloudflare uses various IP ranges for its products. Some customers also authorize Cloudflare to announce their IP prefixes on their behalf (this is known as BYOIP). Collectively, we can refer to these IPs as managed addresses. To prevent Bad Stuff (defined later) from happening, we prohibit managed addresses from Continue reading

SDN startup Lumina Networks closes shop, citing Covid-19 impact

Lumina Networks, a startup spun-off from the purchase and splintering of Brocade in 2017, is shutting down, citing delays in customer deployments due in part to Covid-19, which starved it for cash. The company had raised $14 million in venture capital, including investments from AT&T and Verizon, but it wasn’t enough.Lumina Networks provided an open source-based SDN controller, called the Lumina SDN Controller, which was formerly the Brocade SDN Controller and power by the OpenDaylight technology. Lumina’s claim to fame was that the SDN Controller could manage both the physical and virtual from the same platform.To read this article in full, please click here