Trunk to Access – Will It Work?
Recently a posted a question to Twitter about connecting two Cisco Catalyst switches. One switch has already booted and has the following configuration:
interface GigabitEthernet0/0 description SW02 switchport mode trunk switchport trunk allowed vlan 1,10,20,30 switchport nonegotiate
The other switch is connected to Gi1/0/48 and has just been powered on. It has no configuration so it is booting with the default configuration. The intention is to onboard a new switch via Catalyst Center using Plug and Play (PNP).
Based on the responses not many people were able to describe what would happen and why or why not this scenario would work. There are some interesting details here and before running into this scenario myself I thought that it might work. Before we can answer if it will work, let’s list what we know at this point in time about the two switches, SW01, and SW02. For SW01 we know that:
- The port is configured as a trunk.
- The VLANs allowed on the trunk are 1,10,20, and 30.
- DTP has been disabled.
- The native VLAN is 1.
For SW02 we know that:
- It will boot with all ports enabled.
- Those ports will be in VLAN 1.
- DTP is enabled on the Continue reading
Worth Exploring: SRv6 Test Topologies
Want to explore SRv6? Cisco engineers put together a repository containing scripts and configs for building SRv6 test topologies. It works with Containerlab and FRR (unless you want to beg a Cisco account team for a Cisco 8000 image or make a sandwich while the IOS XRd image is booting).
Want to use netlab? Jeroen van Bemmel implemented baseline SRv6 support for Nokia SR OS.
Worth Exploring: SRv6 Test Topologies
Want to explore SRv6? Cisco engineers put together a repository containing scripts and configs for building SRv6 test topologies. It works with Containerlab and FRR (unless you want to beg a Cisco account team for a Cisco 8000 image or make a sandwich while the IOS XRd image is booting).
Want to use netlab? Jeroen van Bemmel implemented baseline SRv6 support for Nokia SR OS.
Preparing for the Shapeshifting Tactics of Modern Malware
The dynamic nature of malware trends and the rapid shifts between different types of threats underscore the critical need for adaptive cybersecurity measures.HN713: Network Automation: Where Are We, And Where Can We Go?
Today’s show is roundtable conversation on the state of automation in the networking industry. We discuss takeaways from the recent AutoCon event on network automation, and get into issues such as sources of truth and the role of abstractions in automation. We also talk about the learning, cultural, and business challenges of network automation--and how to get beyond them.
The post HN713: Network Automation: Where Are We, And Where Can We Go? appeared first on Packet Pushers.
HN713: Network Automation: Where Are We, And Where Can We Go?
Welcome to Heavy Networking! On today’s show we’ve got a roundtable conversation on the state of automation in the networking industry. This show was inspired by the recent AutoCon conference, which is a new conference focused specifically on network automation. Ethan Banks and I both attended, as did two our guests, and we’re going share... Read more »Hedge 205: OId Engineering Quotes
For this month’s roundtable, Eyvonne, Tom, and I return to Addresses to Engineering Students by Harrington and Waddell. This book, published in 1912, is a “product of its time,” and hence deserves some trigger warnings. But it is also interesting to see how advice given to engineering students over 100 years ago holds up for today. Have engineering challenges, and the engineering life, changed all that much? What kinds of advice stand the test of time, what kinds do not?
Video: netlab IP Address Management (IPAM)
Did you know that netlab includes full-blown IP address management? You can define address pools (or use predefined ones) and get IPv4 and IPv6 prefixes from those pools assigned to links, interfaces, and loopbacks. You can also assign static prefixes to links, use static IP addresses, interface addresses as an offset within the link subnet, or use unnumbered interfaces.
For an overview of netlab IPAM, watch the netlab address management video (part of the Network Automation Tools webinar), for more details read the netlab addressing tutorial.
You need Free ipSpace.net Subscription to watch the video and Standard ipSpace.net Subscription to watch the rest of the webinar.
Video: netlab IP Address Management (IPAM)
Did you know that netlab includes full-blown IP address management? You can define address pools (or use predefined ones) and get IPv4 and IPv6 prefixes from those pools assigned to links, interfaces, and loopbacks. You can also assign static prefixes to links, use static IP addresses, interface addresses as an offset within the link subnet, or use unnumbered interfaces.
For an overview of netlab IPAM, watch the netlab address management video (part of the Network Automation Tools webinar), for more details read the netlab addressing tutorial.
You need Free ipSpace.net Subscription to watch the video and Standard ipSpace.net Subscription to watch the rest of the webinar.
Measurement and Analysis of Protocols at IETF 118
>At IETF 118 in November 2023 I attended the meeting of the Measurement and Analysis of Protocols Research Group, and here are my impressions from that meeting.Life is Life
The initial idea behind this blog was to have a medium to store and share notes on the different technologies I worked on in an searchable manner. I have decided to step back from work and take a year out so this new life tab of the blog will be for all things non-IT related. I still plan to write technology based blogs over this time (got a few automation projects and Azure tips to share), however this is unlikely to start happening until later into next year.
The Benefits of Comprehensive Observability and Potent Analytics for Enterprise Networks
A real-time, dynamic, and high-definition network map can often provide information about whether the network is functioning properly or whether there are problems with any particular device.What is an IPU (Infrastructure Processing Unit) and How Does it Work?
IPUs (Infrastructure Processing Units) are hardware accelerators designed to offload compute-intensive infrastructure tasks like packet processing, traffic shaping, and virtual switching from CPUs.ML Ops Platform at Cloudflare
We've been relying on ML and AI for our core services like Web Application Firewall (WAF) since the early days of Cloudflare. Through this journey, we've learned many lessons about running AI deployments at scale, and all the tooling and processes necessary. We recently launched Workers AI to help abstract a lot of that away for inference, giving developers an easy way to leverage powerful models with just a few lines of code. In this post, we’re going to explore some of the lessons we’ve learned on the other side of the ML equation: training.
Cloudflare has extensive experience training models and using them to improve our products. A constantly-evolving ML model drives the WAF attack score that helps protect our customers from malicious payloads. Another evolving model power bot management product to catch and prevent bot attacks on our customers. Our customer support is augmented by data science. We build machine learning to identify threats with our global network. To top it all off, Cloudflare is delivering machine learning at unprecedented scale across our network.
Each of these products, along with many others, has elevated ML models — including experimentation, training, and deployment — to a crucial position within Continue reading
AMS-IX Outage: Layer-2 Strikes Again
On November 22nd, 2023, AMS-IX, one of the largest Internet exchanges in Europe, experienced a significant performance drop lasting more than four hours. While its peak performance is around 10 Tbps, it dropped to about 2.1 Tbps during the outage.
AMS-IX published a very sanitized and diplomatic post-mortem incident summary in which they explained the outage was caused by LACP leakage. That phrase should be a red flag, but let’s dig deeper into the details.
AMS-IX Outage: Layer-2 Strikes Again
On November 22nd, 2023, AMS-IX, one of the largest Internet exchanges in Europe, experienced a significant performance drop lasting more than four hours. While its peak performance is around 10 Tbps, it dropped to about 2.1 Tbps during the outage.
AMS-IX published a very sanitized and diplomatic post-mortem incident summary in which they explained the outage was caused by LACP leakage. That phrase should be a red flag, but let’s dig deeper into the details.
D2C223: Accelerating VM Performance With Azure Boost
Azure Boost is a hardware offload of Azure virtual machines designed to improve VM performance. On today's Day Two Cloud we dig into how it works. We also talk about how to implement security in Virtual Network Manager, as well as how to optimize your Azure observability--meaning, how not to blow up your budget with unnecessary logging.
The post D2C223: Accelerating VM Performance With Azure Boost appeared first on Packet Pushers.