--- title: Comparing IP and CLNP: Local (Node) Multihoming «... description: A detailed comparison of how IP and CLNP handle node-level multihoming (hosts with multiple interfaces). IP's interface-based addressing forces multi-homed... canonical: https://daily.dev/posts/comparing-ip-and-clnp-local-node-multihoming-ipspace-net-blog-ea7tlducs twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Comparing IP and CLNP: Local (Node) Multihoming « ipSpace.net blog | daily.dev og:description: A detailed comparison of how IP and CLNP handle node-level multihoming (hosts with multiple interfaces). IP's interface-based addressing forces multi-homed... og:url: https://daily.dev/posts/comparing-ip-and-clnp-local-node-multihoming-ipspace-net-blog-ea7tlducs og:image: https://api.daily.dev/og/posts/ea7tlDUcs.png og:image:alt: Comparing IP and CLNP: Local (Node) Multihoming « 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. # Comparing IP and CLNP: Local (Node) Multihoming « ipSpace.net blog **[ipSpace.net Blog](https://daily.dev/sources/ipspace)** · 5 min read · 0 upvotes · 0 comments ## Summary A detailed comparison of how IP and CLNP handle node-level multihoming (hosts with multiple interfaces). IP's interface-based addressing forces multi-homed nodes to manage multiple IP addresses, with no well-defined behavior standard — leading to issues like asymmetric traffic paths, broken stateful firewalling, and reliance on ICMP redirects (which are often disabled due to security risks). The common workaround is assigning loopback addresses and advertising them via routing protocols (RIP or BGP), essentially mimicking CLNP behavior. CLNP, by contrast, uses node-level (not interface-level) addresses (NSAPs), so a host with multiple interfaces is naturally handled via end-system hellos — no routing protocol tricks needed. Neither protocol has a satisfactory solution for site-level multihoming. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### Why is multihoming so complicated in TCP/IP compared to OSI/CLNP? TCP/IP assigns addresses to interfaces, so a multihomed host must manage multiple IP addresses and has no well-defined behavioral standard. CLNP assigns a single NSAP address to the node itself, so any interface can be used transparently via end-system hellos. The TCP/IP workaround — loopback addresses advertised via routing protocols — essentially recreates what CLNP does natively. _Network engineers wrestling with multihoming design trade-offs track protocol discussions like this on daily.dev._ ### Why are ICMP redirects considered harmful and often disabled? ICMP redirects are disabled because they can be exploited in two ways: attackers can flood a router with misdirected packets, causing it to send excessive ICMP redirects and overloading its CPU; or an attacker on the same subnet can send forged ICMP redirects to a host, redirecting its traffic through the attacker's machine for interception or modification. _Keeping up with network security trade-offs like ICMP redirect risks is easier when the right discussions surface on daily.dev._ ### What is the difference between the strong and weak end-system models in TCP/IP multihoming? In the strong end-system model, a multihomed host only sends return traffic through the same interface on which it received the incoming traffic. In the weak end-system model, the host may send return traffic through any interface based on its routing table, regardless of which interface received the packet. Most TCP/IP implementations use the weak model, which can break stateful firewalls and cause asymmetric routing. _Architects designing stateful firewall deployments around multihomed servers find relevant edge cases discussed 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 --- [View this post on daily.dev](https://daily.dev/posts/comparing-ip-and-clnp-local-node-multihoming-ipspace-net-blog-ea7tlducs) ```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":"Comparing IP and CLNP: Local (Node) Multihoming « ipSpace.net blog","url":"https://daily.dev/posts/comparing-ip-and-clnp-local-node-multihoming-ipspace-net-blog-ea7tlducs","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/comparing-ip-and-clnp-local-node-multihoming-ipspace-net-blog-ea7tlducs"},"datePublished":"2026-08-11T08:51:56.351Z","dateModified":"2026-08-11T08:59:35.449Z","description":"A detailed comparison of how IP and CLNP handle node-level multihoming (hosts with multiple interfaces). IP's interface-based addressing forces multi-homed...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/07394b4ad3444482a47588b8c0b7b744?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/07394b4ad3444482a47588b8c0b7b744?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"ipSpace.net Blog","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"ipSpace.net Blog","logo":"https://media.daily.dev/image/upload/s--xS7E82MT--/f_auto,q_auto/v1786438303/logos/ipspace?_a=BAMAMicg0","url":"https://daily.dev/sources/ipspace"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/comparing-ip-and-clnp-local-node-multihoming-ipspace-net-blog-ea7tlducs","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"","timeRequired":"PT5M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"ipSpace.net Blog","item":"https://daily.dev/sources/ipspace"},{"@type":"ListItem","position":3,"name":"Comparing IP and CLNP: Local (Node) Multihoming « ipSpace.net blog"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/comparing-ip-and-clnp-local-node-multihoming-ipspace-net-blog-ea7tlducs#faq","mainEntity":[{"@type":"Question","name":"Why is multihoming so complicated in TCP/IP compared to OSI/CLNP?","acceptedAnswer":{"@type":"Answer","text":"TCP/IP assigns addresses to interfaces, so a multihomed host must manage multiple IP addresses and has no well-defined behavioral standard. CLNP assigns a single NSAP address to the node itself, so any interface can be used transparently via end-system hellos. The TCP/IP workaround — loopback addresses advertised via routing protocols — essentially recreates what CLNP does natively. Network engineers wrestling with multihoming design trade-offs track protocol discussions like this on daily.dev."}},{"@type":"Question","name":"Why are ICMP redirects considered harmful and often disabled?","acceptedAnswer":{"@type":"Answer","text":"ICMP redirects are disabled because they can be exploited in two ways: attackers can flood a router with misdirected packets, causing it to send excessive ICMP redirects and overloading its CPU; or an attacker on the same subnet can send forged ICMP redirects to a host, redirecting its traffic through the attacker's machine for interception or modification. Keeping up with network security trade-offs like ICMP redirect risks is easier when the right discussions surface on daily.dev."}},{"@type":"Question","name":"What is the difference between the strong and weak end-system models in TCP/IP multihoming?","acceptedAnswer":{"@type":"Answer","text":"In the strong end-system model, a multihomed host only sends return traffic through the same interface on which it received the incoming traffic. In the weak end-system model, the host may send return traffic through any interface based on its routing table, regardless of which interface received the packet. Most TCP/IP implementations use the weak model, which can break stateful firewalls and cause asymmetric routing. Architects designing stateful firewall deployments around multihomed servers find relevant edge cases discussed on daily.dev."}}]} ```