Path Hunting in BGP

BGP is a path vector protocol. This is similar to distance vector protocols such as RIP. Protocols like these, as opposed to link state protocols such as OSPF and ISIS, are not aware of any topology. They can only act on information received by peers. Information is not flooded in the same manner as IGPs where a change in connectivity is immediately flooded while also running SPF. With distance and path vector protocols, good news travels fast and bad news travels slow. What does this mean? What does it have to do with path hunting?

To explain what path hunting is, let’s work with the topology below:

With how the routers and autonomous systems are connected, under stable conditions RT05 will have prefix 198.51.100.1/32 via the following AS paths:

  • 64513 64512
  • 64514 64513 64512
  • 64515 64514 64513 64512

This is also shown visually in the following diagram:

There’s a total of three different paths, sorted from shortest to longest. Let’s verify this:

RT05#sh bgp ipv4 uni
BGP table version is 11, local router ID is 192.168.128.174
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, 
              r RIB-failure, S  Continue reading

Weekend Reads 100323


Google has rolled out “Privacy Sandbox,” a Chrome feature first announced back in 2019 that, among other things, exchanges third-party cookies—the most common form of tracking technology—for what the company is now calling “Topics.”


By virtue of engineering pushing the acceptable boundaries of a system, failures occur. This is inevitable, and that’s also the joy and perils of engineering — discovering the acceptable limits of system resilience.


The resource-intensive inefficiencies inherent to telecom ordering, billing, and service level agreement (SLA) enforcement between carriers is an industry-wide problem that MEF and its member organizations have been working to solve for years.


Cybersecurity agencies from Japan and the U.S. have warned of attacks mounted by a state-backed hacking group from China to stealthily tamper with branch routers and use them as jumping-off points to access the networks of various companies in the two countries.


To help solve this problem, QUIC no longer relies (purely) on IP addresses to define connections. Instead, it assigns a number to each connection (a so-called Connection ID or CID).


You are a distributor that sells your supplier’s brands, so aside from worrying about your own company’s domains, you’ve got nothing else to worry about, right?


Continue reading

Worth Reading: Introduction of EVPN at DE-CIX

Numerous Internet Exchange Points (IXP) started using VXLAN years ago to replace tradition layer-2 fabrics with routed networks. Many of them tried to avoid the complexities of EVPN and used VXLAN with statically-configured (and hopefully automated) ingress replication.

A few went a step further and decided to deploy EVPN, primarily to deploy Proxy ARP functionality on EVPN switches and reduce the ARP/ND traffic. Thomas King from DE-CIX described their experience on APNIC blog – well worth reading if you’re interested in layer-2 fabrics.

Worth Reading: Introduction of EVPN at DE-CIX

Numerous Internet Exchange Points (IXP) started using VXLAN years ago to replace tradition layer-2 fabrics with routed networks. Many of them tried to avoid the complexities of EVPN and used VXLAN with statically-configured (and hopefully automated) ingress replication.

A few went a step further and decided to deploy EVPN, primarily to deploy Proxy ARP functionality on EVPN switches and reduce the ARP/ND traffic. Thomas King from DE-CIX described their experience on APNIC blog – well worth reading if you’re interested in layer-2 fabrics.

Heavy Networking 704: Roundtable Redux: Blaming The Network; Containerlab Love; 400G Envy

Today's Heavy Networking is another roundtable episode. We've assembled a group of network engineers to talk about what's on their minds. Topics today include why other IT departments adn end users are quick to blame the network first, and what can be done about it; using Nokia's open-source Containerlab for testing and development work; and why you shouldn't feel left behind when you hear talk about 400G and 800G networks.

Heavy Networking 704: Roundtable Redux: Blaming The Network; Containerlab Love; 400G Envy

Today's Heavy Networking is another roundtable episode. We've assembled a group of network engineers to talk about what's on their minds. Topics today include why other IT departments adn end users are quick to blame the network first, and what can be done about it; using Nokia's open-source Containerlab for testing and development work; and why you shouldn't feel left behind when you hear talk about 400G and 800G networks.

The post Heavy Networking 704: Roundtable Redux: Blaming The Network; Containerlab Love; 400G Envy appeared first on Packet Pushers.

Calico monthly roundup: September 2023

Welcome to the Calico monthly roundup: September edition! From open source news to live events, we have exciting updates to share—let’s get into it!

 

 

Transforming Container Network Security with Calico Container Firewall

Discover how you can automate security, ensure consistency, and tightly align security with development practices in a microservices environment.

Read blog post

The State of Calico Open Source: Usage & Adoption Report 2023

Get insights into Calico’s adoption across container and Kubernetes environments, in terms of platforms, data planes, and policies.

Read the report.

Open source news

  • Share your Calico Open Source journey and win a $25.00 gift card – Your journey with Calico Open Source matters to us! Share your experience and insight on how you solve problems and build your network security using Calico. Book a meeting to tell us about your journey and where you seek information. As a thank you, we’ll send you a $25.00 gift card!
  • Calico Live – Join the Calico community every Wednesday at 2:00 pm ET for a live discussion about learning how to leverage Calico and Kubernetes for networking and security. We will explore Kubernetes security and policy design, network flow logs and more. Join Continue reading

IBM leans into AI for managed security services

IBM is rolling out AI-based managed services that promise to help network and security operations teams more quickly and effectively respond to enterprise cyber threats.Managed by the IBM Consulting group, the Threat Detection and Response (TDR) Services offering promises 24x7 monitoring, investigation, and automated remediation of security alerts from existing security tools as well as cloud, on-premises, and operational technology systems utilizing the enterprise network. The services can integrate information from more than 15 security event and incident management (SIEM) tools and multiple third-party endpoint and network detection and response packages, for example.To read this article in full, please click here

IBM leans into AI for managed security services

IBM is rolling out AI-based managed services that promise to help network and security operations teams more quickly and effectively respond to enterprise cyber threats.Managed by the IBM Consulting group, the Threat Detection and Response (TDR) Services offering promises 24x7 monitoring, investigation, and automated remediation of security alerts from existing security tools as well as cloud, on-premises, and operational technology systems utilizing the enterprise network. The services can integrate information from more than 15 security event and incident management (SIEM) tools and multiple third-party endpoint and network detection and response packages, for example.To read this article in full, please click here

Virtual networking 101: Bridging the gap to understanding TAP

Virtual networking 101: Bridging the gap to understanding TAP
Virtual networking 101: Bridging the gap to understanding TAP

It's a never-ending effort to improve the performance of our infrastructure. As part of that quest, we wanted to squeeze as much network oomph as possible from our virtual machines. Internally for some projects we use Firecracker, which is a KVM-based virtual machine manager (VMM) that runs light-weight “Micro-VM”s. Each Firecracker instance uses a tap device to communicate with a host system. Not knowing much about tap, I had to up my game, however, it wasn't easy — the documentation is messy and spread across the Internet.

Here are the notes that I wish someone had passed me when I started out on this journey!

A tap device is a virtual network interface that looks like an ethernet network card. Instead of having real wires plugged into it, it exposes a nice handy file descriptor to an application willing to send/receive packets. Historically tap devices were mostly used to implement VPN clients. The machine would route traffic towards a tap interface, and a VPN client application would pick them up and process accordingly. For example this is what our Cloudflare WARP Linux client does. Here's how it looks on my laptop:

$ ip link list
...
18: CloudflareWARP: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP>  Continue reading

Video: What Is Software-Defined Data Center

A few years ago, I was asked to deliver a What Is SDDC presentation that later became a webinar. I forgot about that webinar until I received feedback from one of the viewers a week ago:

If you like to learn from the teachers with the “straight to the point” approach and complement the theory with many “real-life” scenarios, then ipSpace.net is the right place for you.

I haven’t realized people still find that webinar useful, so let’s make it viewable without registration, starting with What Problem Are We Trying to Solve and What Is SDDC.

You need at least free ipSpace.net subscription to watch videos in this webinar.

Video: What Is Software-Defined Data Center

A few years ago, I was asked to deliver a What Is SDDC presentation that later became a webinar. I forgot about that webinar until I received feedback from one of the viewers a week ago:

If you like to learn from the teachers with the “straight to the point” approach and complement the theory with many “real-life” scenarios, then ipSpace.net is the right place for you.

I haven’t realized people still find that webinar useful, so let’s make it viewable without registration, starting with What Problem Are We Trying to Solve and What Is SDDC.

You need at least free ipSpace.net subscription to watch videos in this webinar.
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