Video: Local Area Network Addressing
In the Local Area Network Addressing video (part of How Networks Really Work webinar) I covered numerous obscure LAN addressing details including:
- There’s no layer-2 address in Fibre Channel frames (because FC is routing not bridging);
- Why is the multicast bit lowest bit (0x01) in first byte on Ethernet but highest bit (0x80) on Token Ring or FDDI;
- How some NIC manufacturers never got the memo on what OUI really means.
You need Free ipSpace.net Subscription to watch the video, and the Standard ipSpace.net Subscription to register for upcoming live sessions.
Video: Local Area Network Addressing
In the Local Area Network Addressing video (part of How Networks Really Work webinar) I covered numerous obscure LAN addressing details including:
- There’s no layer-2 address in Fibre Channel frames (because FC is routing not bridging);
- Why is the multicast bit the lowest bit (0x01) in the first byte on Ethernet but the highest bit (0x80) on Token Ring or FDDI;
- How some NIC manufacturers never got the memo on what OUI really means.
You need Free ipSpace.net Subscription to watch the video, and the Standard ipSpace.net Subscription to register for upcoming live sessions.
Steal These Use Cases: 2021’s Technology Wins in the Enterprise
Here's InformationWeek's 2021 collection of use cases, case studies, and interviews with some of the top CIOs and IT leaders across enterprises.Hedge 114: Hardware Hacking 101 with Federico Lucifredi
Hardware hacking isn’t a topic most network engineers are familiar with—but we always used to say that if I can get access to the console of a router, I can eventually get into the box. The same is largely true of all kinds of computing hardware, including laptops, compute nodes connected to a data center fabric, and, again, routers and switches. In this episode of the Hedge, Federico Lucifredi joins Tom Ammon and Russ White to discuss the many options hardware hackers have today.
IPv6 Buzz 092: Listener Questions – NAT66, Stable IPv6 Prefix Delegation And More!
In the latest episode of IPv6 Buzz, we tackle the first listener questions of the year (well, really left over from the end of 2021 but still good ones!). Those questions cover topics including Unique Local Addressing (ULA) and SD-WAN, NAT66, IPv6 prefix delegation, and more.
The post IPv6 Buzz 092: Listener Questions – NAT66, Stable IPv6 Prefix Delegation And More! appeared first on Packet Pushers.
IPv6 Buzz 092: Listener Questions – NAT66, Stable IPv6 Prefix Delegation And More!
In the latest episode of IPv6 Buzz, we tackle the first listener questions of the year (well, really left over from the end of 2021 but still good ones!). Those questions cover topics including Unique Local Addressing (ULA) and SD-WAN, NAT66, IPv6 prefix delegation, and more.Cisco ASR 9000 Series Routers
Cisco already supports industry standard sFlow telemetry across a range of products and the recent IOS-XR Release 7.5.1 extends support to Cisco ASR 9000 Series Routers.
Note: The ASR 9000 series routers also support Cisco Netflow. Rapidly detecting large flows, sFlow vs. NetFlow/IPFIX describes why you should choose sFlow if you are interested in real-time monitoring and control applications.
The following commands configure an ASR 9000 series router to sample packets at 1-in-20,000 and stream telemetry to an sFlow analyzer (192.127.0.1) on UDP port 6343.
flow exporter-map SF-EXP-MAP-1
version sflow v5
!
packet-length 1468
transport udp 6343
source GigabitEthernet0/0/0/1
destination 192.127.0.1
dfbit set
!
Configure the sFlow analyzer address in an exporter-map.
flow monitor-map SF-MON-MAP
record sflow
sflow options
extended-router
extended-gateway
if-counters polling-interval 300
input ifindex physical
output ifindex physical
!
exporter SF-EXP-MAP-1
!
Configure sFlow options in a monitor-map.
sampler-map SF-SAMP-MAP
random 1 out-of 20000
!
Define the sampling rate in a sampler-map.
interface GigabitEthernet0/0/0/3
flow datalinkframesection monitor-map SF-MON-MAP sampler SF-SAMP-MAP ingress
Enable sFlow on each interface for complete visibilty into network traffic.
The diagram shows the general architecture of an sFlow monitoring deployment. All the switches stream sFlow telemetry to a central sFlow analyzer for network Continue reading
Explicit Null in Segment Routing
MPLS is such a user-friendly technology it needs a special label that does nothing.
Why explicit null
Normally, the penultimate router in the LSP removes (pops) the top transport label, so that the egress LSR will deal either with the …
Tier 1 Carriers Performance Report: December, 2021
The post Tier 1 Carriers Performance Report: December, 2021 appeared first on Noction.
Worst Topics To Discuss At A Dinner Party
The holiday season is near. This means you will have to attend dinner parties. And, of course, conversations are the best way to have fun at most events.
When you interact with people at a dinner party, you can talk about various things. For example, you may want to discuss your hobbies, interests, and much more.
However, there are some topics that you should avoid. Here are the worst topics to discuss at a dinner party.
- Controversial Jokes
During dinner parties, you are not banned from making jokes. However, you should avoid controversial topics at all costs. Humor is harmless and good only if it’s not very sarcastic.
Besides that, you may decide to joke about another person that is not at the event. Well, we suggest you do not. That is because the individual you’re talking to may know that person. Additionally, it is not good etiquette to talk behind someone’s back.
- Encouraging Someone To Eat Or Drink
Yes, we understand that at a dinner party eating is mainly the point. But of course, you should never tell someone to eat more. This is, of course, unless you’re the host.
A person may have eaten less as Continue reading
Ghost in the ethernet optic
Ghost in the ethernet optic
A few months ago I stumbled on a tweet pointing out a kind of [SFP optic](https://en.wikiped
How the Internet Really Works Part 2
I’m a little late in posting this, but I thought I’d put it out here anyway. Tomorrow I’m teaching through a three-hour webinar, How the Internet Really Works part 2. From the session description—
This training will provide short reviews of many of these systems and a deeper look at the many tools network engineers can use to discover the information they need to navigate through the DNS and routing systems on the global Internet. This training will be arranged as a set of case studies posing a problem, and then working through tools available to gather the information needed to understand the problem.
SDA and Wireless Part III – understanding AP configurations on the 9800
In this post, we look at the various access point specific configurations that are pushed to a fabric-enabled WLC.
SDA and Wireless Part II – AP onboarding
In this post, we look at how an Access Point is onboarded in a SD-Access fabric.
SDA and Wireless Part I – integrating a 9800-CL WLC into SDA
In this post, we look at how a 9800-CL WLC is integrated into a SD-Access fabric.