# Comparing IP and CLNP: Finding Adjacent Nodes

DevFeed: [Comparing IP and CLNP: Finding Adjacent Nodes](<https://devfeed.tech/articles/comparing-ip-and-clnp-finding-adjacent-nodes-11079.md>)

Original publisher: [Read original article](<https://blog.ipspace.net/2024/10/comparing-ip-clnp-addressing/>)

Published: 2024-10-17T07:10:00Z

Content type: comparison

Language: en

Sources: [ipSpace.net blog](<https://devfeed.tech/sources/ipspace-net-blog.md>)

Topics: [networking](<https://devfeed.tech/topics/networking.md>), [TCP/IP](<https://devfeed.tech/topics/tcp-ip.md>), [Protocol (disambiguation)](<https://devfeed.tech/topics/protocol.md>), [data](<https://devfeed.tech/topics/data.md>)

Tags: [arp](<https://devfeed.tech/tags/arp.md>), [interfaces](<https://devfeed.tech/tags/interfaces.md>), [ip](<https://devfeed.tech/tags/ip.md>), [ipv4](<https://devfeed.tech/tags/ipv4.md>), [ipv6](<https://devfeed.tech/tags/ipv6.md>), [network](<https://devfeed.tech/tags/network.md>), [networking](<https://devfeed.tech/tags/networking.md>), [networking-fundamentals](<https://devfeed.tech/tags/networking-fundamentals.md>), [protocol](<https://devfeed.tech/tags/protocol.md>), [tcp](<https://devfeed.tech/tags/tcp.md>), [tcp-ip](<https://devfeed.tech/tags/tcp-ip.md>)

## AI overview

The article compares TCP/IP and CLNP approaches to finding adjacent nodes. TCP/IP uses subnet masks to determine whether a destination is directly reachable and ARP or Neighbor Discovery to resolve the destination link-layer address, while CLNP nodes advertise NSAP addresses through hello messages that neighboring nodes cache.

## Source excerpt

Now that we know a bit more about addresses in a networking stack (read the whole series) and why CLNP uses node addresses while TCP/IP uses interface addresses, let's see how they solve common addressing problems like finding adjacent nodes. Let's start with the elephant in the room: how do you know whether you can reach a host you want to communicate with directly? In the following diagram, how does A know whether B is sitting next to it? Read more ...