She broke barriers at NASA and contributed to its earliest space missions as a rocket scientist, mathematician and computer programmer.

Annie Easley was a member of the team at NASA’s Lewis Research Center in Cleveland (now the Glenn Research Center) given the critical task of fixing the Centaur’s design. Unlike most people working on the project, she was not an engineer. She hadn’t even finished college. But she was an excellent mathematician and computer programmer who was adept at solving problems.

The Department of Defense had concluded that the Centaur would not be ready for at least several more years, a critical setback for the country.

But 18 months later, on Nov. 27, 1963, the redesigned rocket system successfully blasted into space. It was the beginning of a new era in spaceflight, and Easley’s calculations had been vital to the mission. //

Easley had been hired in 1955 to work at Lewis as a human computer — one of a group of gifted women who calculated and solved complex mathematical problems before there were mechanical computers powerful enough to do the work.

The 2016 book and film “Hidden Figures” memorialized the work of some of these pioneers. Like the women depicted in that history, Easley was Black and had to overcome obstacles to succeed, but she did not let that stop her.

“When people have their biases and prejudices, yes, I am aware. My head is not in the sand,” she said in a 2001 oral history interview for NASA. “But my thing is, if I can’t work with you, I will work around you.”

Sean Spicer
@seanspicer
·
Follow
@POTUS @realDonaldTrump kicks off #BlackHistoryMonth with a proclamation from @WhiteHouse recognizing the work of Thomas Sowell, Clarence Thomas, Harriet Tubman and Frederick Douglass
6:47 PM · Jan 31, 2025

Throughout our history, black Americans have been among our country’s most consequential leaders, shaping the cultural and political destiny of our Nation in profound ways. American heroes such as Frederick Douglass, Harriet Tubman, Thomas Sowell, Justice Clarence Thomas, and countless others represent what is best in America and her citizens. Their achievements, which have monumentally advanced the tradition of equality under the law in our great country, continue to serve as an inspiration for all Americans. We will also never forget the achievements of American greats like Tiger Woods, who have pushed the boundaries of excellence in their respective fields, paving the way for others to follow.

This National Black History Month, as America prepares to enter a historic Golden Age, I want to extend my tremendous gratitude to black Americans for all they have done to bring us to this moment, and for the many future contributions they will make as we advance into a future of limitless possibility under my Administration.

This is a long time coming. For years, the accomplishments of black Americans like Thomas and Sowell have been overlooked, downplayed, and blatantly ignored by the left, who seemingly can't handle any black person who doesn't fall into line with their radical policies. Back in 2016, the Smithsonian opened the National Museum of African American History and Culture with nary a word about Clarence Thomas to be found in the entire building, something Rep. Byron Donalds (R-FL) later called an "irresponsible bias." The Smithsonian eventually added Justice Thomas to an existing display about Justice Thurgood Marshall. Mighty nice of them. //

Ronster
3 hours ago
Since the very first time I heard the phrase "celebrate diversity" I have asked why not celebrate unity. As in United States. But then that's the Leftist/Marxist/Democrat way: diversity = divide and conquer.

Baja Sun Ronster
2 hours ago
Diversity is the key to controlling the population.
The more diverse the cultures, the less likely we are to stand united against a tyrannical government.
Divide and conquer.

Ordo amoris was defined by Saint Augustine of Hippo in the fifth century, but best exposition on this heirarchy is in Saint Thomas Aquinas's Summa Theologica. https://en.wikipedia.org/wiki/Summa_Theologica

1. There is an order in charity, and God is the principle of that order. God is to be loved out of charity, before all others. The other beings that are to be loved out of charity are, so to speak, lined up in their proper places, subordinate to God.

2. God is to be loved for himself and as the cause ofhappiness. Hence, God is to be loved more than our neighbor, who isloved, not for himself, but for God.

3. And we are to love God more than we love ourselves. What we love in ourselves is from God, and is lovable only on account of God.

4. A person rightly loves himself by charity when he seeks to be united with God and to partake of God's eternal happiness. And a person loves his neighbor as one to whom he wishes this union and happiness. Now, since seeking to obtain something for oneself is a more intense act than wishing well to one's neighbor, a person manifestly loves himself more than he loves his neighbor. As evidence of this fact, consider this: a man would rightly refuse to sin if, by sinning, he could free his neighbor from sin.

5. While we love ourselves more than we love our neighbor, we are required to love our neighbor more than we love our body.

6. And we rightly love one neighbor more than another - our parents, for instance, or our children. In this we violate no law so long as we do not withhold requisite love from any neighbor.

7. Our dearest objects of charity among neighbors are those who are closest to us by some tie - relationship, common country, and so on.

8. The tie that is strongest of all is the tie of blood. Hence it is natural that we should love our kindred more than others.

9. And in those related to us by blood there is an order. St. Ambrose says that we ought to love God first, then our parents, then our children, then the others of our household.

10. We are to love father and mother. Strictly speaking, the love of father precedes the love of mother.

11. A man loves his wife more intensely than he loves his parents. Yet he loves his parents with greater reverence.

12. It seems that we love those on whom we confer benefits more than those who confer benefits on us.

13. The order of charity, since it is right and reasonable, will endure in heaven.

In fact, Aquinas, being Aquinas, even offered objections to his thesis and defended against the objections.
https://www.newadvent.org/summa/3026.htm

Laocoön of Troy Steprock
3 hours ago
We've done this before...

From March 16, 1916, to February 14, 1917, an expeditionary force of more than fourteen thousand regular army troops under the command of Brig. Gen. John J. "Black Jack" Pershing operated in northern Mexico "in pursuit of Villa with the single objective of capturing him and putting a stop to his forays. Another 140,000 regular army and National Guard troops patrolled the vast border between Mexico and the United States to discourage further raids. //

anon-pkys Laocoön of Troy
36 minutes ago
Back in the 1840s the U.S. declared war on Mexico. We had two small armies that attacked, one from the north across the border, and one by sea from Vera Cruz. Our troops, although greatly out numbered kicked A$$ and took names in several battles with the Mexican Army. We conquered and held Mexico City in a battle in which we were outnumbered. Texas Rangers served as Scouts for the Army and as shock troops. They were hated and feared by the Mexicans. To this day the Mexican people have no love for the Texas Rangers. During the 1870s-80s the Texas Rangers guarded much of the border with Mexico. They were not afraid to go into Mexico after Mexican rustlers.

The discovery of a ship, missing for five centuries, in a southwest African desert, filled with gold coins, is one of the most thrilling archaeological finds in recent times.

The Bom Jesus (The Good Jesus) was a Portuguese vessel that set sail from Lisbon, Portugal on Friday, March 7, 1533. Its fate was unknown until 2008 when its remains were discovered in the desert of Namibia during diamond mining operations near the coast of the African nation.

On January 17, 1961, in this farewell address, President Dwight Eisenhower warned against the establishment of a "military-industrial complex."

In a speech of less than 10 minutes, on January 17, 1961, President Dwight Eisenhower delivered his political farewell to the American people on national television from the Oval Office of the White House. Those who expected the military leader and hero of World War II to depart his Presidency with a nostalgic, "old soldier" speech like Gen. Douglas MacArthur's, were surprised at his strong warnings about the dangers of the "military-industrial complex."

As President of the United States for two terms, Eisenhower had slowed the push for increased defense spending despite pressure to build more military equipment during the Cold War’s arms race. Nonetheless, the American military services and the defense industry had expanded a great deal in the 1950s. Eisenhower thought this growth was needed to counter the Soviet Union, but it confounded him. Though he did not say so explicitly, his standing as a military leader helped give him the credibility to stand up to the pressures of this new, powerful interest group. He eventually described it as a necessary evil.

A vital element in keeping the peace is our military establishment. Our arms must be mighty, ready for instant action, so that no potential aggressor may be tempted to risk his own destruction. . . . American makers of plowshares could, with time and as required, make swords as well. But now we can no longer risk emergency improvisation of national defense; we have been compelled to create a permanent armaments industry of vast proportions. . . . This conjunction of an immense military establishment and a large arms industry is new in the American experience. . . .Yet we must not fail to comprehend its grave implications. . . . In the councils of government, we must guard against the acquisition of unwarranted influence, whether sought or unsought, by the military-industrial complex. The potential for the disastrous rise of misplaced power exists and will persist.

For this final installment in the inauguration series, we talk about the inaugural balls.

Well-known academic and go-to source for U.S. intelligence and military agencies, Professor John Esposito of Georgetown University, insists that nothing bad was happening during the "five centuries of peaceful coexistence" between Muslims and Christians prior to the First Crusade, which was launched by cynical and evil Europeans, forever turning Islam against the West.

Is that true? My answer follows:
https://youtu.be/hgrrMhxAaog

DonnaM
9 hours ago
I'm thinking that a "deal deal" with Greenland and Denmark could be structured like an economic development corporation (EDC). These are nonprofits that work with geographic areas in cities cooperating with businesses to supply plans and services to develop that area. I'm a humble marketer and no expert, but I'd bet that the Trumps have worked with plenty of them. That way we get security and access to resources, kick out the Chinese (mandatory), help Denmark on their issues with Greenland, Greenlanders are part of the EDC representation, run their affairs, improve their economy, yet the Danes keep it as a territory or state. We don't take it on as a US colony or territory, but it's supervised, planned against specified goals. A win all around. //

anon-201n
9 hours ago
This idea of acquiring Greenland at first sounds crazy, but as noted Harry Truman wanted to buy it from Denmark in 1946, at a time when the USSR was beginning to flex its post-war muscles. Greenland has lots of natural resources but also. has a coastline that would open into a northwest passage. Both China (declaring itself an Arctic country!!!) and Russia are eying the Arctic Ocean for its trade routes and natural resources. Greenland has had an uneasy relationship with Denmark over the recent years and is subsidised by Denmark (but also restricted). Trump eyes Greenland as an ally and a trade source and is playing the art of the deal.

Damocles Gordon of Cartoon
9 hours ago
This from Wikipedia:
In 2016, the BBC published a report which stated that the administration of United States President Jimmy Carter (1977–1981) had extensive contact with Ayatollah Ruhollah Khomeini and his entourage in the prelude to the Iranian Revolution of 1979.[1][2] The report was based on "newly declassified US diplomatic cables".[1][2] According to the report, as mentioned by The Guardian, Khomeini "went to great lengths to ensure the Americans would not jeopardise his plans to return to Iran - and even personally wrote to US officials" and assured them not to worry about their interests in Iran, particularly oil.[1][2] According to the report, in turn, Carter and his administration helped Khomeini and made sure that the Imperial Iranian army would not launch a military coup

There are a lot of people here in the USA that do not know that Carter Gave the Ayatollah Khomeini a crap ton of money (read: Millions) and allowed them to take over Iran. The thanks for using our tax money was a bunch of hostages held for over a year.
Look it up people! //

epaddon
9 hours ago
The context of giving away the Panama Canal stemmed from all the 1970s self-flagellation America went through in the wake of Vietnam. The idea of America a force of evil in the world, which gained ascendancy with opposition to the Vietnam War, combined with the rise of "revisionist" scholarship on the Cold War which blamed America, not Stalin for why the Cold War started, and all the trashing of America over getting rid of Marxist regimes in Guatemala and Chile is why Jimmy Carter felt that giving away the Canal would be a way of showing America making amends for all those things they never had to apologize for in the first place.

It didn't help that he not only got the backing RINO Senator Howard Baker, but also the backing of William F. Buckley. Indeed, there was a big "Firing Line" debate between Buckley and Reagan on the Canal and its telling that on Buckley's side was George Will, while Reagan's side had Pat Buchanan. George Will of course now stands exposed as Never-Trumper fake. //

Almost Sane
7 hours ago
Jimmy Carter was a virulent anti-Semite. He hated Israel and did his best to always side with their enemies, even after he was out of office. He was responsible for the ayatollah taking over Iran and responsible for our embassy being overrun and our diplomats taken hostage for over 440 days. Everybody praised him for his Habitat for Humanity project, but failed to read his antisemitic writings long after he was no longer president. //

anon-pabn
9 hours ago
This all may be Trump leveraging the canal to bring to light what China is trying to do with Taiwan. "Go after Taiwan and say goodbye to controlling the Panama Canal." Of course he would refuse to take military action off the board. He is playing 3 dimensional chess while the MSM is playing Candy Crush.

The last few years revealed stark differences in philosophy regarding the role of government in our society. When the level of fear was high, people were more inclined to submit to onerous mandates. They believed restricting freedom was necessary for the common good and saw the government as a benevolent savior. It was terrifying to watch.

Some people want the government to control as much as possible.

This led me to an existential question: What is the point of government? //

“Society is produced by our wants, and government by our wickedness; the former promotes our happiness positively by uniting our affections, the latter negatively by restraining our vices. The one encourages intercourse, the other creates distinctions. The first a patron, the last a punisher.”

Paine described the purpose of government as providing for freedom and security.

“Here then is the origin and rise of government; namely, a mode rendered necessary by the inability of moral virtue to govern the world; here too is the design and end of government, viz. freedom and security.”

Steve Guest @SteveGuest
·
.@ScottJenningsKY: “In the run up to the Persian Gulf War, [Jimmy Carter] wrote letters, to all of our allies, and to Arab States, asking them to abandon their cooperation and coalition with the USA.. if it’s not treasonous, it’s borderline treasonous.” 🔥

11:18 PM · Dec 30, 2024

JENNINGS: In the run-up to the Persian Gulf War, he wrote letters to all of our allies and to Arab states, asking them to abandon their cooperation and coalition with the United States of America. If it's not treasonous, it's borderline treasonous, and so I hear what you're saying about the humanitarianism, but when you're an ex-president, and you have served in that office, I think you have a duty to the United States and only to the United States, and when he did that and other instances, to me, it showed that he cared more about his own legacy than he did about the country, and I think that is wrong. //

Scott Jennings @ScottJenningsKY
·
My thoughts on Jimmy Carter’s legacy last night on @cnn: terrible president, soundly rejected by the American people. Even worse ex-president, whose meddling in US foreign policy & virulent anti-Israel/anti-Semitic views must not be forgotten. Undermined US interests repeatedly.

6:58 AM · Dec 31, 2024
https://x.com/ScottJenningsKY/status/1874062472384307315

Ricardo Dale
4 hours ago
Carter handed us the current terror state that is Iran. Then he called Israel an "apartheid state." He is only partially redeemed by the fact that Joe Biden was worse by a large margin...

it's an opportune time to refresh ourselves on some of the traditions and rituals that occur on the death of the person who wore the illustrious mantle of the leader of the free world.

440-pound 1980s behemoth rescued from an Osaka restaurant days before demolition. //

For those who want the absolute largest CRT experience possible, Sony's KX-45ED1 model (aka PVM-4300) has become the stuff of legends. The massive 45-inch CRT was sold in the late '80s for a whopping $40,000 (over $100,000 in today's dollars), according to contemporary reports.

That price means it wasn't exactly a mass-market product, and the limited supply has made it something of a white whale for CRT enthusiasts to this day. While a few pictures have emerged of the PVM-4300 in the wild and in marketing materials, no collector has stepped forward with detailed footage of a working unit. //

Enter Shank Mods, a retro gaming enthusiast and renowned maker of portable versions of non-portable consoles. In a fascinating 35-minute video posted this weekend, he details his years-long effort to find and secure a PVM-4300 from a soon-to-be-demolished restaurant in Japan and preserve it for years to come. //

The full video includes lots of footage and details of the shipping and unboxing process, and confirmation that the TV still works after its incredible journey. Shank Mods also includes a breakdown of the internal design and processing hardware that went into such a uniquely large CRT and an extended discussion of the intricate process of calibrating and tuning the tube to deliver a sharp, color-corrected picture after years of magnetic and electron beam drift.

https://www.youtube.com/watch?v=JfZxOuc9Qwk

“This is a strange Christmas Eve. Almost the whole world is locked in deadly struggle…. [B]efore we turn again to the stern task and the formidable year that lie before us, resolved that, by our sacrifice and daring, these same children shall not be robbed of their inheritance or denied their right to live in a free and decent world.” //

OwenKellogg-Engineer | December 25, 2024 at 6:09 am
I just finished reading “The Splendid and the Vile” by Erik Larson, about Churchills first year as PM (May 1940-May 1941). What an incredible insight into one of the 20th Century’s most prominent figure. He truly understood that the freedom of western civilization was at stake.

My, how we have slipped away in such a short period of time…..

President Jimmy Carter and Panamanian Chief of Government Omar Torrijos signed the Panama Canal Treaty and Neutrality Treaty on September 7, 1977. This agreement relinquishes American control over the canal by the year 2000 and guarantees its neutrality. On May 4, 1904, Panama granted the United States the right to build and operate the canal and control the five miles of land on either side of the water passage in exchange for annual payments. For the history of the Panama Canal, visit the Library of Congress American Memory section.

Appendix B: Texts of the Panama Canal Treaties with United States Senate Modifications -- Panama

Wednesday 19th June 2013 08:28 GMT
John Smith 19Gold badge
Coat
PDP 11 odds and ends.
The PDP 11 (like the PARC Alto) had a main processor built from standard 4 bit TTL "ALU" parts and their companion "register file." So 2nd, 3rd,4th sourced. I'm not sure how many mfg still list them on their available list in the old standard 0.1" pin spacing.

El Reg ran a story that Chorus (formerly British Steel) ran them for controlling all sorts of bits of their rolling mills but I can't recall if they are

I think the core role for this task is the refueling robots for the CANDU reactors. CANDU allows "on load" refuelling. The robots work in pairs locked onto each end of the pressurized pipes that carry the fuel and heavy water coolant/moderator. They then pressurize their internal storage areas, open the ends and one pushes new fuel bundles in while the other stores the old ones, before sealing the ends. However CANDU have been working on new designs with different fuel mixes (CANDU's special sauce (C Lewis Page) is that it's run with unenriched Uranium, which is much cheaper and does not need a bomb making enrichment facility) and new fuel bundle geometries, so time for a software upgrade.

And 128 users on a PDP 11/70. Certain customers ran bespoke OSes in the early 90s that could get 300+ when VMS could only support about less than 20 on the same spec.

Note for embedded use this is likely to be RSX rather than VMS, which also hosted the ICI developed RTL/2, which was partly what hosted the BBC CEEFAX service for decades.

Yes, it's an anorak.. //

Wednesday 19th June 2013 18:20 GMT
Jamie JonesSilver badge
Thumb Up
Who's laughing?
I feel much better knowing this.

What is the alternative? Buggy software written by the "'Have you tried switching it off and on again" generation? Wednesday 19th June 2013 20:24 GMT
bscottm
Reply Icon
Re: It just costs money
It's not the GHz clock cycle that is the problem. It's the smaller feature size of the transistors that increases the single event upset (SEU) rate. Yes, the two are inter-related, but one could conceivably build multi-core, chip symmetric multiprocessors based on the PDP-11 at today's feature sizes and not have GHz clock cycle times (and still end up with significant SEU rates.)

A couple of years ago, a NASA/JPL scientist pointed out that the alpha particles (helium nuclei) from lead solder were causing interesting issues with current x86_64 I/O pins -- radiation issues on commodity hardware. //

Wednesday 19th June 2013 07:32 GMT
Duncan Macdonald
RSX11M - Dave Cutler
Anyone who read the RSX11M sources (driver writers especially) realised that Dave Cutler was a very very good programmer long before he worked on VMS and later Windows NT. He managed to get a multiuser protected general purpose operating system to work with a minimum memory footprint of under 32kbytes on machines with about the same CPU power as the chip on a credit card. (A 96kByte PDP 11/40 (1/3 mip) with 2 RK05 disks (2.4Mbyte each) could support 2 concurrent programmers - a PDP 11/70 (1 mip) with 1Mbyte and 2 RM03 disk packs (65Mbyte each) could support 10 or more.) During the many years that the CEGB used PDP-11 computers with RSX11M, I did not hear of a single OS failure that was not caused by a hardware fault - I wish that current systems were as good. //

Wednesday 19th June 2013 17:23 GMT
MD Rackham
Reply Icon
Re: RSX11M - Dave Cutler
Of course, that was several years after there was a protected, multi-user timesharing system running on the PDP-8, TSS/8. And it would run in 8K of memory, although you had to spring for 12K for decent performance. Swapped off a fixed-head 256K word disk.

You PDP-11 kids get off my lawn! //

Wednesday 19th June 2013 15:28 GMT
Bastage
Reply Icon
Go
Re: there are alternatives
There is replacement hardware available. NuPDP replacment CPU's including QBUS support and peripheral cards. Also NuVAX for the new kids.

The Reviver boards for PDP-11 and HP1000.

The Osprey PDP-11 and Kestral HP1000 hardware from Strobe Data.

There are also the Stromasys/Charon software emulators VAX/AXP/HP3000. //

Go
Re: there are alternatives
@Peter Gathercole

There is already a well established PDP-11 project on OpenCores:

http://opencores.org/project,w11 //

PDP 11 odds and ends.
The PDP 11 (like the PARC Alto) had a main processor built from standard 4 bit TTL "ALU" parts and their companion "register file." So 2nd, 3rd,4th sourced. I'm not sure how many mfg still list them on their available list in the old standard 0.1" pin spacing.

El Reg ran a story that Chorus (formerly British Steel) ran them for controlling all sorts of bits of their rolling mills but I can't recall if they are

I think the core role for this task is the refueling robots for the CANDU reactors. CANDU allows "on load" refuelling. The robots work in pairs locked onto each end of the pressurized pipes that carry the fuel and heavy water coolant/moderator. They then pressurize their internal storage areas, open the ends and one pushes new fuel bundles in while the other stores the old ones, before sealing the ends. However CANDU have been working on new designs with different fuel mixes (CANDU's special sauce (C Lewis Page) is that it's run with unenriched Uranium, which is much cheaper and does not need a bomb making enrichment facility) and new fuel bundle geometries, so time for a software upgrade.

And 128 users on a PDP 11/70. Certain customers ran bespoke OSes in the early 90s that could get 300+ when VMS could only support about less than 20 on the same spec.

Note for embedded use this is likely to be RSX rather than VMS, which also hosted the ICI developed RTL/2, which was partly what hosted the BBC CEEFAX service for decades. //

Wednesday 19th June 2013 13:20 GMT
PhilBuk
Reply Icon
Happy
Re: PDP 11 odds and ends.
Most real-time systems stayed as PDP-11 when the industry realised that the interupt latency on VAX/VMS was too slow for a lot of applications. You could improve it with a ccustomised VMS kernel but, in most cases, it was cheaper to stick with the devil you knew. Similarly, a friend worked for a measuring company that were using embedded PDP-8 systems as controllers well into the end of the 90s. used to drive round with a clip-on PDP-8 front panel in the boot of his car.

Phil. //

Thursday 20th June 2013 08:25 GMT
FrankAlphaXII
Reply Icon
Re: PDP 11 odds and ends.
Its a certainly a CANDU reactor and its fuel bundle loader robots from what it looks like.

CANDU is a different type of reactor than what gets built most of the time, they can burn just about anything, from some unenriched uranium with some slightly enriched uranium at the same time, to thorium, to Mixed Oxide fuels partially from decommissioned nuclear weapons, to "fun" transuranic actinides and also (as a proliferation concern) some quite nasty fuel mixes which can breed massive (relatively speaking of course) amounts of Plutonium if the reactor isn't properly safeguarded. Thats where India and probably Pakistan bred most of their Special Materials.

And what's cool about this is if the PDP-11 is what GE is using in Canada for their loaders, then its probably what they're using in India, South Korea, Romania, Argentina and China as well, as they also have CANDU reactors or designs derived from CANDU. //

Gather around the fire for another retelling of computer networking history. //

Systems Approach A few weeks ago I stumbled onto an article titled "Traceroute isn’t real," which was reasonably entertaining while also not quite right in places.

I assume the title is an allusion to birds aren’t real, a well-known satirical conspiracy theory, so perhaps the article should also be read as satire. You don’t need me to critique the piece because that task has been taken on by the tireless contributors of Hacker News, who have, on this occasion, done a pretty good job of criticism.

One line that jumped out at me in the traceroute essay was the claim "it is completely impossible for [MPLS] to satisfy the expectations of traceroute." //

Many of them hated ATM with a passion – this was the height of the nethead vs bellhead wars – and one reason for that was the “cell tax.” ATM imposed a constant overhead (tax) of five header bytes for every 48 bytes of payload (over 10 percent), and this was the best case. A 20-byte IP header, by contrast, could be amortized over 1500-byte or longer packets (less than 2 percent).

Even with average packet sizes around 300 bytes (as they were at that time) IP came out a fair bit more efficient. And the ATM cell tax was in addition to the IP header overhead. ISPs paid a lot for their high-speed links and most were keen to use them efficiently. //

The other field that we quickly decided was essential for the tag header was time-to-live (TTL). It is the nature of distributed routing algorithms that transient loops can happen, and packets stuck in loops consume forwarding resources – potentially even interfering with the updates that will resolve the loop. Since labelled packets (usually) follow the path established by IP routing, a TTL was non-negotiable. I think we might have briefly considered something less than eight bits for TTL – who really needs to count up to 255 hops? – but that idea was discarded.

Route account
Which brings us to traceroute. Unlike the presumed reader of “Traceroute isn’t real,” we knew how traceroute worked, and we considered it an important tool for debugging. There is a very easy way to make traceroute operate over any sort of tunnel, since traceroute depends on packets with short TTLs getting dropped due to TTL expiry. //

ISPs didn’t love the fact that random end users can get a picture of their internal topology by running traceroute. And MPLS (or other tunnelling technologies) gave them a perfect tool for obscuring the topology.

First of all you can make sure that interior routers don’t send ICMP time exceeded messages. But you can also fudge the TTL when a packet exits a tunnel. Rather than copying the outer (MPLS) TTL to the inner (IP) TTL on egress, you can just decrement the IP TTL by one. Hey presto, your tunnel looks (to traceroute) like a single hop, since the IP TTL only decrements by one as packets traverse the tunnel, no matter how many router hops actually exist along the tunnel path. We made this a configurable option in our implementation and allowed for it in RFC 3032. //

John Smith 19Gold badge
Coat
Interesting stuff
Sorry but yes I do find this sort of stuff interesting.

Without an understanding of how we got here, how will we know where to go next?

Just a thought. //

doublelayerSilver badge
Responding to headlines never helps
This article's author goes to great lengths to argue against another post based on that post's admittedly bad headline. The reason for that is simple: the author has seen the "isn't real" bit of the headline and jumped to bad conclusions. It's not literal, but it's also not satire a la "birds aren't real". The article itself explains what they mean with the frequent claims that traceroute "doesn't exist":

From a network perspective, traceroute does not exist. It's simply an exploit, a trick someone discovered, so it's to be expected that it has no defined qualities. It's just random junk being thrown at a host, hoping that everything along the paths responds in a way that they are explicitly not required to. Is it any surprise that the resulting signal to noise ratio is awful?

I would have phrased this differently, without the hyperbole, because that clearly causes problems. This response makes no point relevant to the network administration consequences of a traceroute command that is pretty much only usable by people with a lot of knowledge about the topology of any networks they're tracing through and plenty more about what that command is actually doing. Where it does respond, specifically the viability of traceroute in MPLS, it simplifies the problem by pointing out that you can, if you desire, manually implement the TTL field, then goes on to describe the many different ways you can choose not to, ways that everyone chose to use. It is fair to say the author of the anti-traceroute article got it wrong when they claimed that MPLS couldn't support it, but in practice, "couldn't support" looks very similar to "doesn't because they deliberately chose not to". It is similar enough that it doesn't invalidate the author's main point, that traceroute is a command that is dangerous in the hands of people who aren't good at understanding why it doesn't give them as much information as they think it does. //

ColinPaSilver badge

It's the old problem
You get the first version out there, and see how popular it is. If it is popular you can add more widgets to it.

If you spend time up front doing all things, that with hindsight, you should have done, you would never ship it. Another problem is you can also add all the features you think might be used, in the original version, and then find they are not used, or have been superseded.

I was told, get something out there, for people to try. When people come hammering on your door, add the things that multiple people want.

20 hrs
the spectacularly refined chapSilver badge

Re: It's the old problem
Cf the OSI network stack, which took so long to standardise that widespread adoption of IP had already filled the void it was intended to.

In some ways that is not ideal, 30+ years on there is still no standard job submission protocol for IP, OSI had it from the start.

Florida is known as the “Sunshine State” but South Dakota may have claimed it before Florida.

The first South Dakota flag was made in 1909. One side of the state flag was to include a sun and the words “The Sunshine State” according to the South Dakota Secretary of State website. //

The state also has more sun than its neighbors to the east. Multiple weather data websites said the state averages about 213 sunny days. There are about 200 days in Iowa and about 198 sunny days in Minneapolis, Minnesota. North Dakota has about 201 sunny days. //

Thrifty South Dakotans may have led to the loss of the “Sunshine State” nickname.

The two-side flag with the words “The Sunshine State” existed until 1962. Legislators decided that a flag with two distinct sides was too costly to make. It cost residents too much to buy it, so few state flags were flown, according to the S.D. SOS website said.

The flag design was changed in 1963 but “Sunshine State” hung around, apparently.

“In 1992, a measure sponsored by State Rep. Gordon Pederson of Pennington County, South Dakota, changed the wording on the flag to read “The Mount Rushmore State,” the S.D. SOS website said.

Out with the sun, in with the faces of the famous four.

But perhaps known to South Dakotans by 1992, the Florida Legislature had already taken action 22 years prior to officially adopt the nickname “The Sunshine State.”

Statesymbolsusa.org said the Florida lawmakers passed the measure in 1970. That state is also known as the “Peninsula State” for its shape. Florida has on average 273 sunny days.

Have you ever wondered how the chips inside your computer work? How they process information and run programs? Are you maybe a bit let down by the low resolution of chip photographs on the web or by complex diagrams that reveal very little about how circuits work? Then you've come to the right place!

The first of our projects is aimed at the classic MOS 6502 cpu processor. ///

load some assembly language and watch the paths light up on the CPU die