Introduction

IP multicasting is a bandwidth-conserving technology that reduces traffic because it simultaneously delivers a single stream of information to thousands of corporate recipients and homes. Applications that take advantage of multicast include video conferencing, corporate communications, distance learning, and distribution of software, stock quotes, and news. This document discusses the basics of how to configure multicast for various networking scenarios.

In the 1960s, Bob Taylor worked at the heart of the Pentagon in Washington DC. He was on the third floor, near the US defence secretary and the boss of the Advanced Research Projects Agency (Arpa).

Arpa had been founded early in 1958 but was quickly eclipsed by Nasa, leading Aviation Week magazine to dismiss it as "a dead cat hanging in the fruit closet".

Nevertheless, Arpa muddled on - and in 1966, Taylor and Arpa were about to plant the seed of something big.

Next to his office was the terminal room, a pokey little space where three remote-access terminals with three different keyboards sat side by side.

Each allowed Taylor to issue commands to a far-away mainframe computer.

One was based at Massachusetts Institute of Technology (MIT), more than 700km (450 miles) up the coast.

The other two were on the other side of the country - one at the University of California and the Strategic Air Command mainframe in Santa Monica, called the AN/FSQ32XD1A, or Q32 for short.

Each of these massive computers required a different login procedure and programming language.
The next step was obvious, Taylor said. "We ought to find a way to connect all these different machines."

Taylor talked to Arpa's boss, Charles Herzfeld, about his goal.

"We already know how to do it," he said, although it was not clear that anyone really did know how to connect together a nationwide network of mainframe computers.

"Great idea," said Herzfeld. "Get it going. You've got $1m more in your budget right now. Go."

The meeting had taken 20 minutes.

Taylor, Roberts and their fellow networking visionaries had something much more ambitious in mind - a network to which any computer could connect.

As Roberts put it at the time, "almost every conceivable item of computer hardware and software will be in the network".

The solution was proposed by another computing pioneer, physicist Wesley Clark.

Clark had been following the emergence of a new breed of computer.

The minicomputer was modest and inexpensive compared with the room-sized mainframes installed in universities across the United States.

Clark suggested installing a minicomputer at every site on this new network.

The local mainframe - the hulking Q-32, for example - would talk to the minicomputer sitting close beside it.

The minicomputer would then take responsibility for talking to all the other minicomputers on the network - and for the new-and-interesting problem of moving packets of data reliably around the network until they reached their destination.

All the minicomputers would run in the same way - and if you wrote a networking program for one of them, it would work on them all.

Adam Smith, the father of economics, would have been proud of the way Clark was taking advantage of specialisation and the division of labour - perhaps his defining idea.

The existing mainframes would keep on doing what they already did well.

The new minicomputers would be optimised to reliably handle the networking without breaking down.

Each local mainframe had to be programmed merely to talk to the little black box beside it - the local minicomputer.

If you could do that, you could talk to the entire network that stood behind it.

The little black boxes were actually large and battleship grey.

They were called Interface Message Processors (IMPs).

The IMPs were customised versions of Honeywell minicomputers, which were the size of refrigerators and weighed more than 400kg (63 stone) apiece.

They cost $80,000 each, more than $500,000 (£405,000) in today's money.

The network designers wanted message processors that would sit quietly, with minimal supervision, and just keep on working, come heat or cold, vibration or power surge, mildew, mice, or - most dangerous of all - curious graduate students with screwdrivers.

Military-grade Honeywell computers seemed like the ideal starting point, although their armour plating may have been overkill.

On 29 October 1969, two mainframe computers exchanged their first word through their companion IMPs.

It was, somewhat biblically: "Lo".

The operator had been trying to type: "Login" and the network had collapsed after two letters.

A stuttering start - but the Arpanet had been switched on.

The DC court giveth what it taketh away. //

While the court did uphold most of the FCC’s decision, it rejected the agency’s right to strip US states’ of their power to regulate net neutrality as they see fit. That may make all the difference.

When a host is connected to a link or network, it acquires an IP address and all communication take place using that IP address on that link. As soon as, the same host changes its physical location, that is, moves into another area / subnet / network / link, its IP address changes accordingly, and all the communication taking place on the host using old IP address, goes down.

IPv6 mobility provides a mechanism for the host to roam around different links without losing any communication/connection and its IP address.

Care-of Address: When a Mobile Node gets attached to a Foreign Link, it acquires a new IP address of that Foreign Link’s subnet. Home Agent maintains the information of both Home Address and Care-of Address. Multiple Care-of addresses can be assigned to a Mobile Node, but at any instance, only one Care-of Address has binding with the Home Address.

IP Networking, part 4 - the Fundamentals of IPv6

Just as IPv4 addressing can be challenging when managing limited IP address space, IPv6 brings new challenges when working with enormous IP address space. A new mindset is required to effectively understand and implement IPv6 in your network. New IPv6 features and capabilities also bring challenges to the broadcast network engineer.

In this guide, I create a separate WiFi interface for phones and tablets.

Phones rarely need full network access to other local devices. And they have a nasty habit of getting lost, stolen or otherwise broken, so having a separate WiFi access point (and password) means you don’t accidentally disclose your main WiFi password.

A network which can access the Internet, but not other machines on the LAN. Not even ethernet frames.

NTP Pool Servers

IPv6 Subnetting Calculator

Input an IPv6 address and the subnet size in slash notation:
IPv6 address:
Compressed Address: 2607:f1c0:832:ef00::80/56
Expanded Address: 2607:f1c0:0832:ef00:0000:0000:0000:0080/56
Prefix: ffff:ffff:ffff:ff00:0000:0000:0000:0000
Range: 2607:f1c0:832:ef00:0:0:0:0
2607:f1c0:832:efff:ffff:ffff:ffff:ffff
Number of /64s: 256

Select a number of subnets or a subnet size to divide the above into:
subnets or

Subnetting 2607:f1c0:832:ef00::80/56 into /64s gives 256 subnets, all of which have 1 /64s.

2607:f1c0:832:ef00::/64
....
2607:f1c0:832:efff::/64

Use the above calculator to plan your IPv6 networks. Because of the huge size of IPv6, we do not care about the number of hosts in a network. Remember, that the smallest recommended subnet is a /64.

IPv6 or IP version 6 is the next generation Internet protocol which will eventually replace the current protocol IPv4. IPv6 has a number of improvements and simplifications when compared to IPv4. The primary difference is that IPv6 uses 128 bit addresses as compared to the 32 bit addresses used with IPv4. This means that there are more available IP addresses using IPv6 than are available with IPv4 alone. For a very clear comparison, in IPv4 there is a total of 4,294,967,296 IP addresses. With IPv6, there is a total of 18,446,744,073,709,551,616 IP addresses in a single /64 allocation.

To also help illustrate the sheer magnitude of available IP addresses using IPv6, you can get 65536 /64 allocations out of a single /48, and then 65536 /48 allocations out of a single /32. Many Service Providers are getting /32 allocations from their Regional Internet Registry (RIR) like ARIN, APNIC, RIPE, etc.

Huawei offers a new wireless LTE CPE B612 with powerful LTE modem recently. The B612 CPE supports LTE Advanced Cat6 with up to 300 MBit/s in the downlink and up to 50 MBit/s in the uplink, which is similar to the predecessor Huawei E5186 and B525 technically. A special feature compared to the predecessor model is the support for 4 × 4 MIMO antenna technology. The router also offers a telephone function and connections for external LTE antennas, which are common specs for the Huawei LTE routers.

Daniel Kaye testified in his investigation — which took place in Germany — that the operation he carried out was ordered by the CEO of Cellcom Liberia, Avishai Marciano.

According to court testimony, Kaye was hired in 2015 to attack Lonestar, Liberia’s top mobile phone and Internet provider. Kaye pocketed $10,000 for the attack, which was alleged to have been paid for by an individual working for Cellcom, Lonestar’s competitor in the region. As reported by Israeli news outlet Haaretz, Kaye testified that the attack was ordered by the CEO of Cellcom Liberia.

MONROVIA – LoneStar Cell MTN says it has initiated a lawsuit against Mr. Daniel Kaye, a British hacker who took down their internet in 2015 and early 2017. Cellcom Liberia, now Orange Liberia and some of its operatives including Avishai Marziano form

Beamont’s story noted that a botnet based on Mirai was seen attacking the telecommunications infrastructure in the West African nation of Liberia. Citing anonymous sources, Beaumont said transit providers confirmed an attack of more than 500 Gpbs targeting Liberia’s lone underseas large-transit Internet cable, which Beaumont said “provides a single point of failure for internet access.” //

The only problem that I can see with these stories is that there does not appear to have been anything close to a country-wide outage as a result of this Mirai attack.

Daniel Brewer, general manager for the Cable Consortium of Liberia, confirmed that his organization has fielded inquiries from news outlets and other interest groups following multiple media reports of a nationwide outage. But he could not point to the reason.

Daniel Kaye attacked an African mobile phone company, inadvertently taking Liberia offline in 2016.

Liberia has been briefly cut off from the internet by hackers targeting its only link to the global network.

Täht enlisted the aid of Ham the mechanical monkey. Ham, it seems, works in the marketing department. He only cares about benchmarks; if the numbers are big, they will help to sell products. [Dave Täht] Ham has been the nemesis for years, driving the focus in the wrong direction. The right place to focus is on use cases, where the costs of bufferbloat are felt. That means paying much more attention to latency, and focusing less on the throughput numbers that make Ham happy.

As an example, he noted that the Slashdot home page can, when latency is near zero, be loaded in about eight seconds (the LWN page, he said, was too small to make an interesting example). If the Flent tool is used to add one second of latency to the link, that load takes nearly four minutes. We have all been in that painful place at one point or another. The point is that latency and round-trip times matter more than absolute throughput.

Unfortunately, the worst latency-causing bufferbloat is often found on high-rate connections deep within the Internet service provider's infrastructure. That, he said, should be fixed first, and WiFi will start to get better for free. But that is only the start. WiFi need not always be slow; its problems are mostly to be found in its queuing, not in external factors like radio interference. The key is eliminating bufferbloat from the WiFi subsystem.

Addressing and Subnetting on the Near Side of the 'Net

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