# BGPexpert News, opinions and resources from the inter-domain routing and IPv6 worlds This is one page of public article previews, not the complete archive. Follow Next page to continue. Summaries are not the original full articles. ## -\> BGP handling bug causes widespread internet routing instability DevFeed: [-\> BGP handling bug causes widespread internet routing instability]() Original publisher: [Read original article]() Published: 2025-05-28T13:06:04Z Content type: article Language: en Sources: [BGPexpert](), [benjojo blog]() Topics: [BGP](), [Routing (disambiguation)](), [incident](), [networking](), [Internet Traffic]() Tags: [bgp](), [bug](), [eos](), [incident](), [internet-traffic](), [juniper](), [network](), [route](), [router](), [routing](), [servers]() ### AI overview The article analyzes a May 20, 2025 BGP incident in which a corrupt BGP Prefix-SID attribute containing zeroed internal data interacted with JunOS and Arista EOS behavior. JunOS propagated the message, while Arista EOS devices reset sessions, causing routing instability and potentially brief connectivity loss for some networks. ### Source excerpt benjojo reports: At 7AM (UTC) on Tuesday May 20th 2025 a BGP message was propagated that triggered surprising (to many) behaviours with two major BGP implementations that are often used for carrying internet traffic. This caused a large number of "internet facing" BGP sessions to automatically shut down, causing at the very least some routing instability, and at worst brief loss of connectivity for some networks. BGP implementations failing in various ways after seeing something incorrect/unexpected is definitely not a new thing... ## BGP training course at NL-ix in Zoetermeer October 7 DevFeed: [BGP training course at NL-ix in Zoetermeer October 7]() Original publisher: [Read original article]() Published: 2024-07-15T09:54:40Z Content type: news Language: en Sources: [BGPexpert]() Topics: [BGP](), [Protocol (disambiguation)]() Tags: [bgp](), [course](), [dutch](), [gateway](), [information](), [learn](), [protocol](), [scheduled](), [training](), [work]() ### AI overview NL-ix is scheduled to hold a one-day BGP training course in Zoetermeer on October 7, led by Iljitsch van Beijnum. Participants will learn BGP internals, with instruction offered in English or Dutch according to participant preferences. ### Source excerpt NL-ix brings back its famous BGP (Border Gateway Protocol) course. The course is scheduled to happen on October 7. It will be conducted by Iljitsch van Beijnum. In one day (09.30 - 16.00) course participants will learn the internals of BGP protocol. This will help them with a much better understanding of their current BGP work. In English or Dutch depending on the wishes/needs of the participants. More information and registration. ## BGP training course at NL-ix in Zoetermeer June 3 DevFeed: [BGP training course at NL-ix in Zoetermeer June 3]() Original publisher: [Read original article]() Published: 2024-05-27T13:35:06Z Content type: news Language: en Sources: [BGPexpert]() Topics: [BGP](), [Protocol (disambiguation)]() Tags: [3](), [bgp](), [course](), [protocol](), [training]() ### AI overview NL-ix is bringing back its one-day BGP training course in Zoetermeer on June 3, conducted by Iljitsch van Beijnum. The English-language course covers BGP internals and is intended to improve participants' understanding of their current BGP work. ### Source excerpt NL-ix brings back its famous BGP (Border Gateway Protocol) course. The course is scheduled to happen on 3rd June. It will be conducted by Iljitsch van Beijnum. In one day (09.30 - 16.00) course participants will learn the internals of BGP protocol. This will help them with a much better understanding of their current BGP work. In English. Hopelijk binnenkort ook weer in het Nederlands. Meer informatie en inschrijven ## Upgrading Fiber To The Home to terabit speeds DevFeed: [Upgrading Fiber To The Home to terabit speeds]() Original publisher: [Read original article]() Author: Iljitsch van Beijnum Published: 2024-04-09T11:16:41Z Content type: opinion Language: en Sources: [BGPexpert]() Topics: [Network](), [BGP](), [Internet](), [Artificial Intelligence]() Tags: [bgp](), [cost](), [network](), [passive-optical-network](), [performance](), [pon]() ### AI overview This opinion article considers whether home fiber networks could reach terabit-class speeds. It argues that BGP should continue to support much faster links and discusses WDM, tuned lasers, passive optical buses, and PON as possible components, while identifying transmitter cost as the main challenge. ### Source excerpt Last week, Jaap van Till asked me if BGP would be capable of supporting the terabit class interconnectivity that he foresees we'll need in the future, possibly due to the rise of artificial intelligence. He explains his reasoning in the blog post What Link speeds will we need for AI, where he quotes VAN TILL's CONJECTURE: The network connection Wide Area access speed will grow in time until it matches the internal device BUS speed of the more and more complex processors and datastores. And then concludes that 14 Tbps external links will be required in 2039. Today I can get 4 Gbps where I live. So that means a 70% speed increase per year. Let's first get that BGP question out of the way: I see no problems. 25 years ago I ran BGP over 64 and 128 kbps links without trouble. Six orders of magnitude later, BGP is still fine, and there is no reason to believe that even faster speeds will be a problem, just as long as the packet loss rates remain minimal. But what would terabit class network connectivity at home look like? Actually, I think we have all the parts to build this today. With Wavelength Devision Multiplexing (WDM), it's possible to transmit multiple data streams through a single fiber by using slightly different wavelengths/frequencies of infrared laser light. Coarse WDM (CWDM) is relatively cheap and appropriate over shorter distances, with 18 wavelengths standardized over high performance fiber. (Fewer over most existing fiber.) For long distances, dense WDM (DWDM) can use as many as 160 wavelengths over a single fiber pair. Bandwidth per wavelength is now 100 or 200 Gbps, and expected to increase in the future. So anything between say 10 x 100 Gbps = 1 Tbps and the 20 Tbps used by modern seacables should be possible. The catch is of course the cost. The difficulty is with the transmitting side, as this requires a tuned laser per wavelength. On the receiving side, the wavelengths can be split using a prism and hit a set of wideband receivers. As someone who i ## -\> Enforcing First AS in BGP DevFeed: [-\> Enforcing First AS in BGP]() Original publisher: [Read original article]() Author: lindsay Published: 2023-10-08T14:00:49Z Content type: tutorial Language: en Sources: [BGPexpert]() Topics: [BGP](), [Security](), [Cisco](), [Network](), [Internet]() Tags: [bgp](), [cisco](), [juniper](), [network](), [router](), [security]() ### AI overview This article explains the BGP First AS requirement for eBGP peers, including the security and loop-prevention reasons for enforcing it. It discusses Juniper and Cisco behavior, route-server exceptions at internet exchanges, and the limitation that some routers expose the setting globally rather than per neighbor. ### Source excerpt The BGP RFCs state that external BGP peers should insert their own AS into the AS PATH advertised to eBGP peers. Some peers strip their AS, generally for commercial gain. Juniper and Cisco have opposite default behaviors for handling this. Make sure you set bgp enforce-first-as on Juniper routers. Caveats apply. The annoying part here is that you want to disable this check for internet exchange route servers, but keep it enabled for everything else for security reasons. But that's not universally possible, as on some routers this is a global setting, rather than a per-neighbor one.