--- title: OSPFv3 Router ID Documentation on Arista EOS «... description: Arista EOS OSPFv3 documentation for the router-id command contains misleading and incorrect information across multiple releases. Key omissions include: the... canonical: https://daily.dev/posts/ospfv3-router-id-documentation-on-arista-eos-ipspace-net-blog-4gkybeyfe twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: OSPFv3 Router ID Documentation on Arista EOS « ipSpace.net blog | daily.dev og:description: Arista EOS OSPFv3 documentation for the router-id command contains misleading and incorrect information across multiple releases. Key omissions include: the... og:url: https://daily.dev/posts/ospfv3-router-id-documentation-on-arista-eos-ipspace-net-blog-4gkybeyfe og:image: https://api.daily.dev/og/posts/4gkYbEyfE.png og:image:alt: OSPFv3 Router ID Documentation on Arista EOS « 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. # OSPFv3 Router ID Documentation on Arista EOS « ipSpace.net blog **[ipSpace.net Blog](https://daily.dev/sources/ipspace)** · 2 min read · 0 upvotes · 0 comments ## Summary Arista EOS OSPFv3 documentation for the router-id command contains misleading and incorrect information across multiple releases. Key omissions include: the router ID selection algorithm uses IPv4 addresses (not IPv6), and OSPFv3 won't start without a valid router ID, making explicit configuration mandatory on IPv6-only devices. The configuration guide compounds the problem by incorrectly stating that IPv6 addresses are used for router ID selection. Three implementation gotchas are highlighted: the show command gives no indication when OSPFv3 fails to start due to a missing router ID, EOS silently allows removal of a configured router-id even when no IPv4 fallback exists, and removing the last IPv4 address used for router ID raises no warning. This can result in a bricked network after reboot. The EOS documentation was fixed around release 4.36.0F. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### Does OSPFv3 on Arista EOS use IPv6 addresses for router ID selection? No, OSPFv3 on Arista EOS uses IPv4 addresses for router ID selection, not IPv6 addresses. This is a common point of confusion reinforced by incorrect documentation. On an IPv6-only device with no IPv4 addresses and no explicitly configured router-id, the OSPFv3 process cannot start at all. The router-id must be explicitly configured on IPv6-only devices. _Engineers deploying OSPFv3 on IPv6-only Arista devices track gotchas like this on daily.dev._ ### What happens on Arista EOS if OSPFv3 has no valid router ID after reboot? If an Arista EOS device reboots with an OSPFv3 process configured but no valid router ID — either because no IPv4 addresses exist in the VRF and no router-id is explicitly set — the OSPFv3 process will not start. EOS gives no warning when you remove the last IPv4 address or the configured router-id, and the show ipv6 ospf output does not mention the missing router ID, making diagnosis difficult. _Network engineers managing Arista EOS upgrades and IPv6 migrations follow edge cases like this 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 - [Configuring SRv6 on Junos \(Locator and IGP\) « ipSpace.net blog](https://daily.dev/posts/configuring-srv6-on-junos-locator-and-igp-ipspace-net-blog-bhavnkj81) · ipSpace.net Blog · 0 upvotes · 0 comments --- [View this post on daily.dev](https://daily.dev/posts/ospfv3-router-id-documentation-on-arista-eos-ipspace-net-blog-4gkybeyfe) ```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":"OSPFv3 Router ID Documentation on Arista EOS « ipSpace.net blog","url":"https://daily.dev/posts/ospfv3-router-id-documentation-on-arista-eos-ipspace-net-blog-4gkybeyfe","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/ospfv3-router-id-documentation-on-arista-eos-ipspace-net-blog-4gkybeyfe"},"datePublished":"2026-08-11T08:55:58.841Z","dateModified":"2026-08-11T09:27:05.365Z","description":"Arista EOS OSPFv3 documentation for the router-id command contains misleading and incorrect information across multiple releases. 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This is a common point of confusion reinforced by incorrect documentation. On an IPv6-only device with no IPv4 addresses and no explicitly configured router-id, the OSPFv3 process cannot start at all. The router-id must be explicitly configured on IPv6-only devices. Engineers deploying OSPFv3 on IPv6-only Arista devices track gotchas like this on daily.dev."}},{"@type":"Question","name":"What happens on Arista EOS if OSPFv3 has no valid router ID after reboot?","acceptedAnswer":{"@type":"Answer","text":"If an Arista EOS device reboots with an OSPFv3 process configured but no valid router ID — either because no IPv4 addresses exist in the VRF and no router-id is explicitly set — the OSPFv3 process will not start. EOS gives no warning when you remove the last IPv4 address or the configured router-id, and the show ipv6 ospf output does not mention the missing router ID, making diagnosis difficult. Network engineers managing Arista EOS upgrades and IPv6 migrations follow edge cases like this on daily.dev."}}]} ```