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Category Archives for "Networking"

HPE announces Arm-based Ampere servers

HP Enterprise says it will deliver a series of servers powered by the Arm-based Altra and Altra Max by Ampere, the CPU startup run by former Intel executive Renee James.Ampere, not to be confused with the GPU processor of the same name from Nvidia, has scored some wins with cloud providers, notably Microsoft Azure and Oracle Cloud Infrastructure, but it had yet to land in OEM partner. Until now.Starting in Q3 2022, HPE says it will ship ProLiant RL300 Gen11 servers, available for both outright purchase and for leasing through HPE’s GreenLake consumption model. HPE says this will be the first in a series of HPE ProLiant RL Gen11 servers using 80-core Altra and 128-core Altra Max processors.To read this article in full, please click here

Modifying Administrative Distance of Specific BGP Route

In one of the Discords that I’m in there was a user with a complex network consisting of a mix of DMVPN, BGP over MPLS VPN circuits, and SD-WAN. For some prefixes, the path via the private MPLS is preferred, for others, the SD-WAN path. Now, if a prefix is available in two different protocols, BGP vs Overlay Management Protocol (OMP), there is nothing we can do in BGP or OMP to modify which one gets installed into the Routing Information Base (RIB). This is no different than if EIGRP and OSPF were competing to install a prefix into the RIB, the protocol with the lower Administrative Distance (AD) would have its route installed.

The default AD values used on a Cisco device for these protocols are:

  • eBGP – 20
  • iBGP – 200
  • OMP – 251

Based on the AD, OMP will always lose out. It is of course possible to change the AD of BGP, but that would have an effect of all prefixes and we lose the ability to have some prefixes preferred via BGP and others via OMP. I had never changed the AD of a specific BGP prefix before, so I turned to Twitter to see Continue reading

Weekend Reads 070122


For decades, hopeful techies have been promising a world where absolutely every object you encounter—bandages, bottles, bananas—will have some kind of smarts thanks to supercheap programmable plastic processors.


To be clear, current artificial intelligence systems are decades away from being able to experience feelings and, in fact, may never do so.


The fact that LaMDA in particular has been the center of attention is, frankly, a little quaint. LaMDA is a dialogue agent. The purpose of dialogue agents is to convince you that you are talking with a person.


While it has always seemed absurd that this matter wasn’t addressed before the government extorted huge sums of money from operators for the right to do so, it’s also reasonable to assume the matter is not restricted to the US.


The number of tech layoffs in May alone skyrocketed 780% over the first four months of the year combined, according to outplacement services firm Challenger, Gray & Christmas.


Just before last Christmas, in a first-of-a-kind case, JPMorgan was fined $200M for employees using non-sanctioned applications for communicating about financial strategy.


At the same time, I’ve also noticed what might be called a zero-trust backlash, as it becomes apparent that you can’t Continue reading

Worth Reading: On the Dangers of Cryptocurrencies…

Bruce Schneier wrote an article on the dangers of cryptocurrencies and the uselessness of blockchain, including this gem:

From its inception, this technology has been a solution in search of a problem and has now latched onto concepts such as financial inclusion and data transparency to justify its existence, despite far better solutions to these issues already in use.

Please feel free to tell me how he’s just another individual full of misguided opinions… after all, what does he know about crypto?

Worth Reading: On the Dangers of Cryptocurrencies…

Bruce Schneier wrote an article on the dangers of cryptocurrencies and the uselessness of blockchain, including this gem:

From its inception, this technology has been a solution in search of a problem and has now latched onto concepts such as financial inclusion and data transparency to justify its existence, despite far better solutions to these issues already in use.

Please feel free to tell me how he’s just another individual full of misguided opinions… after all, what does he know about crypto?

Possible Impacts Of Covid-19 On Data Networking

This post originally appeared on the Packet Pushers’ Ignition site on April 22, 2020.   In this post I review what might happen to networking when we return to work. We won’t return to normal, but we will be back at work. To start, here are nine ideas about the pandemic’s impact, divided into two […]

The post Possible Impacts Of Covid-19 On Data Networking appeared first on Packet Pushers.

Micron ships high density SATA-based SSDs for data centers

Micron Technology is bucking the trend of moving to PCI Express-based storage and releasing a new SATA III-based SSD with ultradense memory storage and read optimized for faster data access.The SATA interface has been around since the beginning of the century, but it has progressed much slower than the PCIe interface and with nowhere near the leaps in performance. Among gamers, who are as obsessed with performance as someone doing AI models, PCIe drives are standard issue, and SATA drives are at best used for storage.That’s because SATA III has a throughput of about 550MB/s, while PCIe 4.0 has more than 10 times the throughput.To read this article in full, please click here

Micron ships high density SATA-based SSDs for data centers

Micron Technology is bucking the trend of moving to PCI Express-based storage and releasing a new SATA III-based SSD with ultradense memory storage and read optimized for faster data access.The SATA interface has been around since the beginning of the century, but it has progressed much slower than the PCIe interface and with nowhere near the leaps in performance. Among gamers, who are as obsessed with performance as someone doing AI models, PCIe drives are standard issue, and SATA drives are at best used for storage.That’s because SATA III has a throughput of about 550MB/s, while PCIe 4.0 has more than 10 times the throughput.To read this article in full, please click here

The Linux fold command breaks up text, drives loops

The Linux fold command enables you to break a string of characters into same-size chunks, but it can also be used to provide a series of characters or strings to drive a loop. This post reviews the basic command and then demonstrates how you can use it to loop through the characters or strings that it creates.The basic use of the fold command is to take long lines of text and break them into shorter pieces. One common use is to shorten lines in a text file so that they display well in a terminal window. Lines wider than the terminal width might otherwise wrap in inconvenient places.The fold command can also be used to create a narrower file from a file with lines that are inconveniently long.To read this article in full, please click here

The Linux fold command breaks up text, drives loops

The Linux fold command enables you to break a string of characters into same-size chunks, but it can also be used to provide a series of characters or strings to drive a loop. This post reviews the basic command and then demonstrates how you can use it to loop through the characters or strings that it creates.The basic use of the fold command is to take long lines of text and break them into shorter pieces. One common use is to shorten lines in a text file so that they display well in a terminal window. Lines wider than the terminal width might otherwise wrap in inconvenient places.The fold command can also be used to create a narrower file from a file with lines that are inconveniently long.To read this article in full, please click here

Juniper vQFX on GNS3

The vQFX is a virtualized version of the Juniper Networks QFX10000 Ethernet switches portfolio. It is a free tool that is not sold and therefore not supported by Juniper. The vQFX offers the same control and data plane features as the physical QFX10000 switches with limited software forwarding performance. We can use the vQFX to […]
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SR Linux in Containerlab

This article uses Containerlab to emulate a simple network and experiment with Nokia SR Linux and sFlow telemetry. Containerlab provides a convenient method of emulating network topologies and configurations before deploying into production on physical switches.

curl -O https://raw.githubusercontent.com/sflow-rt/containerlab/master/srlinux.yml

Download the Containerlab topology file.

containerlab deploy -t srlinux.yml

Deploy the topology.

docker exec -it clab-srlinux-h1 traceroute 172.16.2.2

Run traceroute on h1 to verify path to h2.

traceroute to 172.16.2.2 (172.16.2.2), 30 hops max, 46 byte packets
 1  172.16.1.1 (172.16.1.1)  2.234 ms  *  1.673 ms
 2  172.16.2.2 (172.16.2.2)  0.944 ms  0.253 ms  0.152 ms

Results show path to h2 (172.16.2.2) via router interface (172.16.1.1).

docker exec -it clab-srlinux-switch sr_cli

Access SR Linux command line on switch.

Using configuration file(s): []
Welcome to the srlinux CLI.
Type 'help' (and press <ENTER>) if you need any help using this.
--{ + running }--[  ]--                                                                                                                                                              
A:switch#

SR Linux CLI describes how to use the interface.

A:switch# show system sflow status

Get status of sFlow telemetry.

-------------------------------------------------------------------------
Admin State             Continue reading

Optimizing TCP for high WAN throughput while preserving low latency

Optimizing TCP for high WAN throughput while preserving low latency
Optimizing TCP for high WAN throughput while preserving low latency

Here at Cloudflare we're constantly working on improving our service. Our engineers are looking at hundreds of parameters of our traffic, making sure that we get better all the time.

One of the core numbers we keep a close eye on is HTTP request latency, which is important for many of our products. We regard latency spikes as bugs to be fixed. One example is the 2017 story of "Why does one NGINX worker take all the load?", where we optimized our TCP Accept queues to improve overall latency of TCP sockets waiting for accept().

Performance tuning is a holistic endeavor, and we monitor and continuously improve a range of other performance metrics as well, including throughput. Sometimes, tradeoffs have to be made. Such a case occurred in 2015, when a latency spike was discovered in our processing of HTTP requests. The solution at the time was to set tcp_rmem to 4 MiB, which minimizes the amount of time the kernel spends on TCP collapse processing. It was this collapse processing that was causing the latency spikes. Later in this post we discuss TCP collapse processing in more detail.

The tradeoff is that using a low value for Continue reading

Don’t let automation break change management

The drive to automate more and more network operations is a good thing, but it exposes a need for network teams to ensure their change-management processes are in order.Networks are doing more, becoming integral to zero-trust security architectures, for example, and to end-to-end enterprise optimization endeavors. Networks are also connecting more things than ever: Mobile devices and IoT nodes continue to proliferate outside data centers and IaaS environments, while inside the enterprise, VMs and containers and separate environments segregating groups of them from each other for security purposes continue to proliferate.To read this article in full, please click here

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