Fixing an old hack – why we are bumping the IPv6 MTU
Back in 2015 we deployed ECMP routing - Equal Cost Multi Path - within our datacenters. This technology allowed us to spread traffic heading to a single IP address across multiple physical servers.
You can think about it as a third layer of load balancing.
- First we split the traffic across multiple IP addresses with DNS.
- Then we split the traffic across multiple datacenters with Anycast.
- Finally, we split the traffic across multiple servers with ECMP.
When deploying ECMP we hit a problem with Path MTU discovery. The ICMP packets destined to our Anycast IP's were being dropped. You can read more about that (and the solution) in the 2015 blog post Path MTU Discovery in practice.
To solve the problem we created a small piece of software, called pmtud (https://github.com/cloudflare/pmtud). Since deploying pmtud, our ECMP setup has been working smoothly.
Hardcoding IPv6 MTU
During that initial ECMP rollout things were broken. To keep services running until pmtud was done, we deployed a quick hack. We reduced the MTU of IPv6 traffic to the minimal possible value: 1280 bytes.
This was done as a tag on a default route. This is Continue reading
Routing in Data Center: What Problem Are You Trying to Solve?
Here’s a question I got from an attendee of my Building Next-Generation Data Center online course:
As far as I understood […] it is obsolete nowadays to build a new DC fabric with routing on the host using BGP, the proper way to go is to use IGP + SDN overlay. Is my understanding correct?
Ignoring for the moment the fact that nothing is ever obsolete in IT, the right answer is it depends… this time on answer(s) to two seemingly simple questions “what services are we offering?” and “what connectivity problem are we trying to solve?”.
Read more ...Bob Ross, Lorem Ipsum, Heroku and Cloudflare Workers
It may not be immediately obvious how these things are related, but bear with me... It was 4pm Friday and one of the engineers on the Cloudflare Tools team came to me with an emergency. "Steve! The Bob Ross Ipsum generator is down!".
If you've not heard of Lorem Ipsum, it's an extract from a latin poem that designers use as placeholder text when designing the layout of a document. There are generators all over the web that will spit out as much text as you need.
Of course, the web being the web that we all love, there are also endless parodies of Lorem Ipsum. You can generate Hodor Ipsum, Cat Ipsum and Hipster Ipsum. I have a new, undisputed favourite: Bob Ross Ipsum.
Not growing up in the U.S., I hadn't come across the lovable, calm, serene and beautiful human that is Bob Ross. If you haven't spent 30 mins watching him paint a landscape, you should do that now. He built a following as host of the TV show “The Joy of Painting” which ran on the U.S. PBS channel from 1983-1994. He became famous for Continue reading
Introducing Real World Serverless – Practical advice on how to use Cloudflare Workers
We’re getting the best minds on serverless technology from Cloudflare together to lead a series of talks on practical use cases for Cloudflare Workers. Join any of these six global talks for stories of how companies and developers are using serverless in the real world.
San Francisco - London - Austin - Singapore - Sydney - Melbourne
Want a Real World Serverless event in your city? Interested in sharing your stories and experience deploying serverless apps in production? Email [email protected] and let’s put something together.
Check out the event details and register through the Eventbrite links below.
Real World Serverless - San Francisco
Sept 11th, 2018, 6:00pm-9:00pm
In partnership with Serverless Meetup
Location: Heavybit - 325 9th St, San Francisco, CA 94103
View Event Details & Register Here »
Real World Serverless - London
Sept 18th, 2018, 6:00pm-9:00pm
Location: Cloudflare London - 25 Lavington St, Second floor SE1 0NZ London
View Event Details & Register Here »
Real World Serverless - Austin
October 2nd, 2018, 6:00pm-9:00pm
In partnership with ATX Serverless Meetup
Location: Downtown Austin
Website Security Myths
Some conversations are easy; some are difficult. Some are harmonious and some are laborious. But when it comes to website security, the conversation is confusing.
Every organisation agrees, in theory, that their websites need to be secure. But in practice, there is resistance to investing enough time and budget. Reasons for neglecting security include misconceptions surrounding Web Application security.
Below I’ve outlined some of the most common myths and misconceptions that can often put your website at serious security risks.
My website is not the target of an attack because it is small and I run a small business.
An average small business website is attacked 44 times per day. In addition, a low profile website is a nice playground for hackers to try out new tools and techniques. Hackers often use automated tools to find various vulnerable websites and don't discriminate when it comes to the size of the target. Any web application, even if it is not itself a target, may be of interest to attackers. Web applications with lax security are easy pickings for hackers and can be subject to a mass or targeted cyber attack.
The good news is that Continue reading
Even Better MANRS During August
We already discussed the MANRS activities during SANOG 32 where we organised a Network Security Workshop and signed an MoU with the ISP Association of Bangladesh (ISPAB), but the Internet Society was also involved with three other events during the month of August. This included the Symposium on Internet Routing Security and RPKI, VNIX-NOG 2018 and the inaugural INNOG 1.
Symposium on Internet Routing Security and RPKI
ZDNS along with CNCERT organised a symposium on 17th August at Crowne Plaza Beijing to discuss routing security issues and how RPKI can help address this problem. There were many prominent participants representing local, regional and international entities including Baidu, Tencent, Alibaba, Huawei, ZTE, the Chinese Academy of Sciences, APNIC, ICANN, along with the Internet Society.
Dr Stephen Kent (BBN) was the keynote speaker, having played an important role in the SIDR (Secure Internet Domain Routing) Working Group at the IETF (Internet Engineering Task Force) and also co-authored many RFCs (Request for Comments) on RPKI. He discussed the ideas behind RPKI and Route Origin Authorization/Validation.
George Michaelson (APNIC) who along with his colleague Geoff Huston co-authored RFC 6483 – Validation of Route Origination Using the Resource Certificate Public Key Infrastructure (PKI) and Route Origin Authorizations Continue reading
Repost: Tony Przygienda on Valley-Free (or Non-ZigZag) Routing
Most blog posts generate the usual noise from the anonymous peanut gallery (if only they'd have at least a sliver of Statler and Waldorf in them), but every now and then there's a comment that's pure gold. The one made by Tony Przygienda (of RIFT fame) on Valley-Free Routing post is so good and relevant that I decided to republish it as a separate blog post. Enjoy!
Read more ...KVM Host High CPU Fix
Fix 100% CPU with CSR 1000v, vMX, etc.. VMs.Juniper vQFX Vagrant Libvirt Box Install
Build a Juniper vQFX Vagrant box for use with the libvirt provider.KVM Host High CPU Fix
I run my labs on an Ubuntu 1604 host using KVM for the hypervisor and some of the network VM images (Cisco CRS1000v, Juniper vMX, etc..) run with very high CPU. A recent thread on Twitter helped me to find a solution to this problem so I will outline it here as it may be helpful for others. ...Juniper vQFX Vagrant Libvirt Box Install
In this post I will cover how to create a Juniper vQFX Vagrant box for use with the vagrant-libvirt provider. With other Juniper VM's such as the vSRX and vMX there are some required steps to get the KVM host prepped, these may be required for the vQFX also. I did not find any documentation ...Broadcom CEO Dangles CA Technologies Bait, Investors Bite
CEO Hock Tan said the company will sell hardware to new customers and will see a boost from 5G.
BiB 054: Create & Deploy Unikernels With NanoVMs
NanoVMs makes software to help you create and deploy unikernels. In this briefing, CEO Ian Eyberg discussed with Ethan Banks the state of the unikernel ecosystem and how NanoVMs fits into things.
The post BiB 054: Create & Deploy Unikernels With NanoVMs appeared first on Packet Pushers.
Weekly Show 406: Updates And Introspection
On today's Weekly Show the Packet Pushers update you on what's been happening behind the scenes at our Global HQ. That includes a new hosting provider, forthcoming Ignition content, and the launch of the IPv6 podcast. We also take a little time to talk about trying to stay mentally and physically healthy.
The post Weekly Show 406: Updates And Introspection appeared first on Packet Pushers.
HTBASE Provides Composable Infrastructure Across Multiple Clouds
Its pièce de résistance is to use software-defined networking to take resources from clouds and on-premises data centers and make it look like it’s a single data center, all on the same Layer 2.
HashiCorp Fortifies Consul Service Mesh With Kubernetes Support
Consul competes against Istio but has a broader focus on multi-tenancy infrastructure deployments.
SDxCentral’s Weekly Roundup — September 7, 2018
Telefónica taps Netcracker for BSS; Cisco launches hybrid cloud platform for Google Cloud; China considers a merger of its three wireless carriers.