--- title: Feedback: Recursive BGP Next Hop Resolution «... description: A follow-up post collecting expert feedback on the quirks of recursive BGP next hop resolution as described in RFC 4271 section 5.1.3. Key insights include:... canonical: https://daily.dev/posts/feedback-recursive-bgp-next-hop-resolution-ipspace-net-blog-raxdagdqm twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Feedback: Recursive BGP Next Hop Resolution « ipSpace.net blog | daily.dev og:description: A follow-up post collecting expert feedback on the quirks of recursive BGP next hop resolution as described in RFC 4271 section 5.1.3. Key insights include:... og:url: https://daily.dev/posts/feedback-recursive-bgp-next-hop-resolution-ipspace-net-blog-raxdagdqm og:image: https://api.daily.dev/og/posts/raXdAgdqM.png og:image:alt: Feedback: Recursive BGP Next Hop Resolution « ipSpace.net blog og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Feedback: Recursive BGP Next Hop Resolution « ipSpace.net blog **[ipSpace.net Blog](https://daily.dev/sources/ipspace)** · 4 min read · 0 upvotes · 0 comments ## Summary A follow-up post collecting expert feedback on the quirks of recursive BGP next hop resolution as described in RFC 4271 section 5.1.3. Key insights include: the RFC text was never intended to prohibit load balancing but was about rules for advertising paths; real-world complexity explodes when resolving over multiple protocols, MPLS shortcuts, and mixed iBGP/eBGP paths; Junos has a specific knob for BGP next hops resolved over BGP multipath; and load balancing is technically permissible under a creative reading of the RFC if independent recursive lookups are performed per packet. The discussion extends into hierarchical FIB design, chained composite next hops in Junos (up to 5-6 levels of nested lookups), IOS-XR FIB structures, and the hardware engineering trade-offs between lookup depth, TCAM/SRAM usage, power, heat, and manufacturability. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### What was the original intent of RFC 4271 section 5.1.3 regarding BGP next hop resolution and load balancing? RFC 4271 section 5.1.3 was never intended to prohibit load balancing. The text, suggested by Tom Petch, was about rules governing when BGP advertises valid paths or paths it installs in the RIB/FIB. The FIB layer constructs actual forwarding paths, and serious routing stacks implement load balancing across eBGP, iBGP, and mixed MPLS VPN paths independently of this section. _Network engineers navigating BGP load balancing decisions track RFC interpretations and vendor behavior on daily.dev._ ### How many levels of nested lookups does Junos Chained Composite Next Hop involve for MPLS VPN or EVPN? Junos Chained Composite Next Hop for MPLS VPN or EVPN can involve between 5 and 6 levels of nested lookups before reaching the outgoing direct interface, depending on whether port channel is enabled. IOS-XR has a similar structure: VRF prefix → label → BGP protocol next hop → IGP next hop → port channel → OIF, with one or two levels varying by feature. _Engineers designing or troubleshooting MPLS VPN forwarding paths find vendor-specific FIB depth discussions on daily.dev._ ## Similar posts on daily.dev - [The Never-Ending IPv6 Loopback Prefix Saga « ipSpace.net blog](https://daily.dev/posts/the-never-ending-ipv6-loopback-prefix-saga-ipspace-net-blog-4nlhgh10l) · ipSpace.net Blog · 0 upvotes · 0 comments - [BGP-Free Network Core with SRv6 « ipSpace.net blog](https://daily.dev/posts/bgp-free-network-core-with-srv6-ipspace-net-blog-9bbn88wub) · ipSpace.net Blog · 0 upvotes · 0 comments --- Tags: [#bgp](https://daily.dev/tags/bgp) [View this post on daily.dev](https://daily.dev/posts/feedback-recursive-bgp-next-hop-resolution-ipspace-net-blog-raxdagdqm) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Feedback: Recursive BGP Next Hop Resolution « ipSpace.net blog","url":"https://daily.dev/posts/feedback-recursive-bgp-next-hop-resolution-ipspace-net-blog-raxdagdqm","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/feedback-recursive-bgp-next-hop-resolution-ipspace-net-blog-raxdagdqm"},"datePublished":"2026-08-11T08:54:04.414Z","dateModified":"2026-08-11T09:26:19.992Z","description":"A follow-up post collecting expert feedback on the quirks of recursive BGP next hop resolution as described in RFC 4271 section 5.1.3. 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The text, suggested by Tom Petch, was about rules governing when BGP advertises valid paths or paths it installs in the RIB/FIB. The FIB layer constructs actual forwarding paths, and serious routing stacks implement load balancing across eBGP, iBGP, and mixed MPLS VPN paths independently of this section. Network engineers navigating BGP load balancing decisions track RFC interpretations and vendor behavior on daily.dev."}},{"@type":"Question","name":"How many levels of nested lookups does Junos Chained Composite Next Hop involve for MPLS VPN or EVPN?","acceptedAnswer":{"@type":"Answer","text":"Junos Chained Composite Next Hop for MPLS VPN or EVPN can involve between 5 and 6 levels of nested lookups before reaching the outgoing direct interface, depending on whether port channel is enabled. IOS-XR has a similar structure: VRF prefix → label → BGP protocol next hop → IGP next hop → port channel → OIF, with one or two levels varying by feature. Engineers designing or troubleshooting MPLS VPN forwarding paths find vendor-specific FIB depth discussions on daily.dev."}}]} ```