--- title: EVPN Designs: Layer-3 Inter-AS Option A « ipSpace.net blog description: A walkthrough of implementing EVPN Inter-AS Option A for multi-site designs using netlab. Each site runs an independent EVPN fabric connected via a layer-3... canonical: https://daily.dev/posts/evpn-designs-layer-3-inter-as-option-a-ipspace-net-blog-hhj0ruzdt twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: EVPN Designs: Layer-3 Inter-AS Option A « ipSpace.net blog | daily.dev og:description: A walkthrough of implementing EVPN Inter-AS Option A for multi-site designs using netlab. Each site runs an independent EVPN fabric connected via a layer-3... og:url: https://daily.dev/posts/evpn-designs-layer-3-inter-as-option-a-ipspace-net-blog-hhj0ruzdt og:image: https://api.daily.dev/og/posts/HHj0RUzdT.png og:image:alt: EVPN Designs: Layer-3 Inter-AS Option A « 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. # EVPN Designs: Layer-3 Inter-AS Option A « ipSpace.net blog **[ipSpace.net Blog](https://daily.dev/sources/ipspace)** · 8 min read · 0 upvotes · 0 comments ## Summary A walkthrough of implementing EVPN Inter-AS Option A for multi-site designs using netlab. Each site runs an independent EVPN fabric connected via a layer-3 DCI, with separate EBGP sessions per tenant VRF on WAN edge routers. The post traces how routing information propagates from leaf to leaf across sites: EVPN type-5 routes are converted to VRF IPv4 BGP routes at the WAN edge, exchanged over inter-site EBGP, then re-advertised as type-5 routes into the remote site's EVPN fabric. Includes full netlab topology YAML, BGP table outputs, and VRF routing table verification on FRRouting. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### How does EVPN Inter-AS Option A propagate routes between two sites with separate EVPN fabrics? In EVPN Inter-AS Option A, WAN edge routers maintain a separate EBGP session per tenant VRF over the inter-site link. The leaf advertises VLAN prefixes as EVPN type-5 routes; the local WAN edge converts them to VRF IPv4 BGP routes and sends them to the remote WAN edge over the VRF EBGP session. The remote WAN edge then re-advertises them as type-5 EVPN routes into its local fabric. _Network engineers building multi-site EVPN fabrics track design patterns like this on daily.dev._ ### What netlab modules are needed to build a multi-site EVPN lab with VRFs and VXLAN? A multi-site EVPN lab with VRFs and VXLAN requires the ospf, bgp, vxlan, vlan, vrf, and evpn netlab modules. The topology uses FRRouting containers by default (defaults.device: frr) with containerlab as the provider, and symmetric IRB is enabled per VRF via evpn.transit_vni: True. _Those evaluating netlab for EVPN lab automation find relevant topology examples discussed on daily.dev._ ## Similar posts on daily.dev - [EVPN with SR-MPLS Core « ipSpace.net blog](https://daily.dev/posts/evpn-with-sr-mpls-core-ipspace-net-blog-taobtibzc) · ipSpace.net Blog · 0 upvotes · 0 comments --- Tags: [#bgp](https://daily.dev/tags/bgp) [View this post on daily.dev](https://daily.dev/posts/evpn-designs-layer-3-inter-as-option-a-ipspace-net-blog-hhj0ruzdt) ```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":"EVPN Designs: Layer-3 Inter-AS Option A « ipSpace.net blog","url":"https://daily.dev/posts/evpn-designs-layer-3-inter-as-option-a-ipspace-net-blog-hhj0ruzdt","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/evpn-designs-layer-3-inter-as-option-a-ipspace-net-blog-hhj0ruzdt"},"datePublished":"2026-08-11T08:53:11.457Z","dateModified":"2026-08-11T09:13:18.088Z","description":"A walkthrough of implementing EVPN Inter-AS Option A for multi-site designs using netlab. 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