Network == Abstraction Layer @overunderlay@bsd.network

[2] The advice in the core BGP RFC is "SHOULD NOT". It's worth noting that this cautionary form currently incenses the IESG in IETF during their review phase of documents before they ship as RFCs. Because "SHOULD NOT" implies "I can when..." and they don't like the answer that sometimes the preference is "because I want to".

https://www.rfc-editor.org/info/rfc4271/#section-5.1.1

[1] The original cloudlfare post.

https://blog.cloudflare.com/bgp-origin-attribute/

MED tends to be in most people's BGP-101 toolkit. When supported by the receiving provider, it provides a good way to enable a solid "use this connection instead of that connection" feature.

However, even when supported it's a big per-prefix hammer and really only helps in electing a single ingress.

This is why many providers don't use the MED-as-specified feature. Rather, many use MED+IGP variants - that are not standardized in IETF! - to get the job done.

MED is thus not even a good hammer many times, and may be a different tool (screwdriver?) depending on what the receiving provider is willing to do with it. And it only helps if supported by your adjacent AS - which might not be good enough if the traffic you're trying to bias is more than one AS hop away.

As an aside, while the MED feature is beloved by operators, it is a massive PITA to implement. While these posts are about trying to "do something about" ORIGIN, if I had to take a feature to un-make, it'd be MED.

ORIGIN, right below AS_PATH length, offers an "attractive nuisance" to bias traffic.

As the various articles running around have noted, ORIGIN is a vestigial feature partially designed to help with the transition of ARPAnet/Internet routing from EGP to BGP. The primary motivation to move to BGP-4 was support of CIDR so we could get out of classful use of IP address space.

I wasn't there, but talking with those that were, this transition was done very rapidly. As a result, migration mechanisms like ORIGIN to bias route selection and ATOMIC_AGGREGATE to try to avoid programmatic (de-)aggregation were largely non-issues.

It's worth mentioning that even after a second round of moving from RFC 1771 which gave us our second (!) but well deployed version of BGP version 4 to RFC 4271 which cleaned up a lot of issues didn't fully clarify how ORIGIN is used.

Probably the biggest lingering headache is "what is the ORIGIN of my static routes?" Some vendors do IGP, some do Incomplete. The result is that just for harmony in multi-vendor networks the ORIGIN is manually adjusted anyway - so tweaking things isn't exactly foreign to service providers.

This hammer has been getting used further by providers, and its popularity is why we have the current kerfluffle: A service provider may choose to manipulate the ORIGIN at import time. This permits paths that are otherwise of similar length to stay that length, while providing some preference as to which ones you use throughout the AS.

Some of you immediately say "well, why not use LOCAL_PREF?" The simple answer is that LOCAL_PREF is the biggest hammer in the toolbox. It stops caring about AS_PATH length or other tweaks unless you encode your entire AS-wide route selection policy and flatten it into an integer. Most providers say "yuck" and reach for the smaller hammers.

Many providers as part of their policy will simply ignore received ORIGIN values anyway and reset them. This already means that even if the originating AS set it to one value that another may not respect that, expecting manipulation. Instead, they're violating the originating ASes intent.

Which moves into the second part where this slightly smaller hammer is used: It's an attempt to put a lighter hand on incoming traffic load balancing. When it works, it's helpful. But it depends on downstream service providers themselves choosing to respect the upstream provider's desired intent.

AS_PATH length thus is reasonably respected. ORIGIN might help, but is often ignored. The result is the toolbox has one solid tool available, and it is very clumsy.

AS_PATH Length is the tool everyone is used to using to impact attracted traffic: You prepend your own AS to make a path less preferable.

Unfortunately the efficacy of this practice is clumsy. Depending on where you sit in the Internet and who your providers are, you end up playing with the number of prepends to see how well you can influence the incoming traffic.

Excessive prepending opens you up to easier route hijack. (https://datatracker.ietf.org/doc/draft-ietf-grow-as-path-prepending/)

When you're not lucky, traffic load balancing seems fine and then all of a sudden may shift. Often this is how a provider discovers BGP Wedgies where the "state machine that is the Internet" has latched temporally on your advertised routes... and then it moved. (https://datatracker.ietf.org/doc/html/rfc4264)

On an incoming basis, providers may proxy prepend incoming routes to locally bias their traffic. However, that also impacts downstream traffic attraction and thus you have to be careful about that.

There's been some recent discussion covering #bgp routing about the ORIGIN attribute. Pointers to a few items for that discussion follow in the replies, but let's lead with the nice Cloudflare post.[1]

One track follows the fact that RFC 4271 says you SHOULD NOT be changed after it's been originated.[2] But, clearly, that's happening.

Another track has been "we should deprecate this!"[3][4] Good luck with that. Much of the headache for BGP is dealing with incremental deployment. This is baked deep enough into the core protocol that any effort to remove it either at the PDU level or the route selection level sufficient to make a difference isn't something I find likely to happen before I retire.

The missing bit of the conversation is why we're seeing this manipulation at all. The simple answer is that when all you have are hammers, every problem resembles a nail.

Service providers have a very small number of tools in their toolbox to light-handedly shape in-AS traffic. The toolbox to change how traffic is attracted to their AS is just as clumsy.

The subset of BGP's route selection tools available is shown in my very Crayola palette.

Sorry for all the puns but seriously, this is a lot more Drama than we usually get out in the poop world.

Usually it's just "blah blah blah wash your hands" "don't drink poop water"

This is a level of foulup I don't think any wealthy country has ever seen to date. We're making poop history here.

Researchers used electric stoves to treat asthma. It worked.

"Led by Dr. Ash Sehgal, a professor at Case Western’s School of Medicine, researchers recruited families from across the Cleveland and Akron areas where at least one person had asthma. Using funds from the Biden-era Inflation Reduction Act, they replaced gas stoves with electric induction stoves in 91 homes.

And then they did something unprecedented: They studied whether people got less sick after they stopped cooking with gas. It was the first time time scientists had replaced gas ranges with electric ranges and examined the health impacts. "

https://www.climatecoloredgoggles.com/p/electric-stoves-asthma

#inductionovens #airquality #health #electrification #publichealth

How to Know If You’re Eligible for a Piece of the $2.5 Billion Amazon Prime Settlement, and How to File a Claim
https://time.com/article/2026/07/24/amazon-prime-settlement-eligibility-how-to-file-claim/

#JeffBezos #WillLewis #AdamONeal #WashingtonPost #WaPo #Journalism #FreePress #BoycottAmazon #BoycottWholeFoods #EatTheBillionaires #USPol

TIL that in 2024 pope Francis beatified a very clearly queer 16th-century Spanish abbess.

Juana de la Cruz Vázquez Gutiérrez insisted that God changed her gender in the womb, transforming her from male to female.
She dressed as a man to escape her family and join a community of religious women.
In addition she professed that Christ becomes whatever the seeker needs: father, mother, husband, wife, or friend.

https://qspirit.net/madre-juana-de-la-cruz-queer-saint/

#lgbtq #religion #trans #queer #intersex

The fact that you pick your seat at the theater by poking a pictogram on a small screen, rather than by physically sitting down in a seat is one of the myriad ways we've become alienated from our neighbors and the physical world.

The world needs more hackerspaces! I want to help with that. Specifically, in the little slice of Scotland I call home.

I love the existing spaces in Glasgow and Edinburgh, but I know some incredible hackers, makers, and creators who aren't close enough to make those places home.

So, if you know anyone who happens to live in/around the south west coast of Scotland, could you please share this survey with them?

https://tally.so/r/gDxoAl

Implications of RNA virus persistence for post-acute sequelae and chronic inflammatory syndromes https://www.nature.com/articles/s41590-026-02577-5

do you think the CEO of Mouser Electronics, Inc. is informally called "Chief Mouser"?

@sinituulia It really looks like an illustration by J. C. Leyendecker, a very famous American illustrator of the 1st half of the 20th century who was quite openly gay.

https://wwd.com/eye/people/illustrator-j-c-leyendecker-lgbqt-american-masculinity-1235627608/

welp, looks like today's the day for my quarterly repeat of thinking "maybe I should buy scratch tickets just so I can donate to broke free software devs if I win on one"

• gitolite/forgejo -> got
• mastodon -> snac
• blog -> just httpd

There was a commercial for Claude AI before our movie tonight. When it was over, the entire theater booed.

very excited to announce the launch of my new business venture

https://overpaid.lol/

Do you encrypt your private files?