Bridging Packet Walk In VXLAN/EVPN Network

In this post I walk you through all the steps and packets involved in two hosts communicating over a L2 VNI in a VXLAN/EVPN network. The topology below is the one we will be using:

The lab has the following characteristics:

  • OSPF in the underlay.
  • Ingress replication for BUM traffic through the use of EVPN.
  • ARP suppression is enabled.
  • ARP cache is cleared on Server-1 and Server-4 before initating the packet capture.
  • Server-1 is the host sourcing traffic by pinging Server-4.

Server-1 clears the ARP entry for Server-4 and initiates the ping:

sudo ip neighbor del 198.51.100.44 dev ens160
ping 198.51.100.44
PING 198.51.100.44 (198.51.100.44) 56(84) bytes of data.
64 bytes from 198.51.100.44: icmp_seq=1 ttl=64 time=6.38 ms
64 bytes from 198.51.100.44: icmp_seq=2 ttl=64 time=4.56 ms
64 bytes from 198.51.100.44: icmp_seq=3 ttl=64 time=4.60 ms

Below is packet capture showing the ARP request from Server-1:

Frame 7854: 60 bytes on wire (480 bits), 60 bytes captured (480 bits) on interface ens257, id 4
Ethernet II, Src: 00:50:56:ad:85:06, Dst: ff:ff:ff:ff:ff:ff
Address Resolution Protocol (request)
    Hardware type: Ethernet (1)
    Protocol type:  Continue reading

DNS and Truncation in UDP

I’ll press on with another item within an overall theme of some current work in DNS behaviours with a report of a recent measurement on the level of compliance of DNS resolvers with one aspect of standard-defined DNS behaviour: truncation of DNS over UDP responses.

DNS and Truncation in UDP

I’ll press on with another item within an overall theme of some current work in DNS behaviours with a report of a recent measurement on the level of compliance of DNS resolvers with one aspect of standard-defined DNS behaviour: truncation of DNS over UDP responses.

Boat build phase – part2

You can only live for so long on laughing cow, pot noodles, soup and beans on toast, the boat diet is good for losing weight but not for your wellbeing. I got lucky with the weather as winter was pretty mild up until late October but when it turned you certainly did feel the cold on the boat. You would have to be crazy to try and survive on a boat in winter without a stove or some form of heating.

SuzieQ Network Observability

SuzieQ Network Observability

In today’s post, we’re exploring SuzieQ, an open-source network observability platform that’s making waves in the way we monitor and understand our networks. It supports a wide array of devices from top vendors like Arista, Cisco, and Juniper, among others. We’ll start with the fundamentals and finish with a practical example to clearly illustrate how SuzieQ sets itself apart from other automation tools.

What We Will Cover?

  1. What exactly is SuzieQ?
  2. How does SuzieQ work?
  3. How to install SuzieQ?
  4. SuzieQ terminology (Configuration, Inventory, suzieq-cli, poller)
  5. Configuration and Inventory files
  6. Examples using OSPF Topology
  7. Path Analysis

What Exactly is SuzieQ?

I first came across SuzieQ a while back but didn't dive deep into it because tools like Netmiko or Napalm were fitting my needs just fine. That changed when I tuned into a recent Packet Pushers podcast featuring Dinesh Dutt, the brain behind SuzieQ. Hearing him talk about it got me really interested.

After the podcast, I couldn't hold back from giving SuzieQ a try. There have been many times when I found myself writing custom scripts to get things done, only to discover that SuzieQ could have handled those tasks much more smoothly.

So, what is SuzieQ? In simple Continue reading

How do we overcome Imposter Syndrome?

How do we overcome Imposter Syndrome?

I was thinking of writing about Imposter Syndrome for so long but I didn't because I thought someone might figure out I don't know what I am talking about.

This is so real, I'm not even kidding. The feeling of doubting your abilities and feeling like a fraud. It's something many of us experience, especially when we're stepping out of our comfort zones or tackling new challenges. So, I decided to face this head-on and share some ways to deal with it. First, it's important to recognize when we're being too hard on ourselves. We often set unrealistically high standards and then beat ourselves up when we don't meet them. It's okay to not know everything – after all, we're all learning as we go.

Talking to others can also be a big help. You'll often find that many people feel the same way and have their own experiences with Imposter Syndrome. This can be a huge relief to know you're not alone in this.

What Exactly is Imposter Syndrome?

In plain terms, it's when you feel like you're not as competent as others perceive you to be. You might think you're not good enough, despite there being clear signs Continue reading

Weekend Reads 022334


The European Court of Human Rights (ECHR) has ruled that laws requiring crippled encryption and extensive data retention violate the European Convention on Human Rights – a decision that may derail European data surveillance legislation known as Chat Control.


The Electric Power Research Institute (EPRI) says that “better than 80% of all electronic system failures that are attributed to power anomalies are actually the result of electrical wiring or grounding errors or are generated by other loads within the customer’s facility.”


With research making considerable progress in designing quantum computers, it is time to consider the scenario that usable quantum computing will become a reality in the future. In this post, we discuss the testbed that we are setting up to empirically evaluate the impact of quantum-safe cryptography algorithms on DNSSEC.


Late last year, Congress extended Section 702 of the Foreign Intelligence Surveillance Act (FISA) and, in doing so, secured the nation’s warrantless surveillance powers until April 2024. With that month fast approaching, House Republicans have unveiled a new package to reauthorize those same powers, within limits.


Google has announced that it’s open-sourcing Magika, an artificial intelligence (AI)-powered tool to identify file types, to help defenders accurately detect binary Continue reading

Technology Short Take 175

Welcome to Technology Short Take #175! Here’s your weekend reading—a collection of links and articles from around the internet on a variety of data center- and cloud-related topics. I hope you find something useful here!

Networking

Security

  • I attended a local meetup here in the Denver metro area a short while ago and was introduced to sops.
  • AMD processors have been discovered to have multiple security flaws; more details available here.
  • The Linux kernel project has become a CVE Numbering Authority (CNA); Greg Kroah-Hartman wrote a blog post that discusses this in more depth.

Cloud Computing/Cloud Management

Intel: I Was Lostry, But Now I Am Foundry

Pat Gelsinger, current chief executive officer at Intel and formerly the head of its Data Center Group as well as its chief technology officer, famously invented the tick-tock method of chip launches to bring some order and reason to the way the world’s largest chip maker – as it was in the mid-2000s – mitigated risk and spurred innovation in its products. …

Intel: I Was Lostry, But Now I Am Foundry was written by Timothy Prickett Morgan at The Next Platform.

VyOS 1.4 LTS released

Protectli Vault - 4 Port

The VyOS 1.4.0 (Sagitta) LTS release announcement is exciting news! VyOS is an open source router operating system based on Linux that can be installed on commodity PC hardware - for optimal performance at least 1GB RAM and 4GB of storage space is recommended.

The new 1.4 LTS release includes a significantly enhanced implementation of industry standard sFlow telemetry based on the open source Host sFlow agent.

set system sflow interface eth0
set system sflow interface eth1
set system sflow interface eth2
set system sflow interface eth3
set system sflow polling 30
set system sflow sampling-rate 1000
set system sflow drop-monitor-limit 50
set system sflow server 192.0.2.100
Enter the commands above to enable sFlow monitoring on interfaces eth0, eth1, eth2, and eth3. Interface counters will be exported every 30 seconds, packets will be sampled with probability 1/1000, and up to 50 packet headers (and drop reasons) per second will collected from packets dropped by the router. The sFlow telemetry stream will be sent to an sFlow collector at 192.0.2.100.

Running Docker on the sFlow collector makes it easy to run a variety of Continue reading

Hedge 214: Hardware Offloading

Network operators increasingly rely on generic hosts, rather than specialized routers (appliances) to forward traffic. Much of the performance on hosts relies on offloading packets switching and processing to specialized hardware on the network interface card. In this episode of the Hedge, Krzysztof Wróbel and Maciej Rabęda join Russ and Tom to talk about hardware offloading.

download

You can find out more about hardware offloading here.

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