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IPv4 Multicast Subrange Breakdown

IPv4 Multicast Address Ranges Explained

Overview
Multicast is an essential part of modern networking—used for streaming, routing protocols, service discovery, distributed applications, and more. But not all multicast addresses behave the same.

This CSV breaks the IPv4 multicast block (224.0.0.0/4) into its functional subranges, each with its own rules, behaviors, and use cases.

What This CSV Contains

Includes the following categories:

  • 224.0.0.0/24 — Local Network Control
    Used by routing protocols (OSPF, EIGRP, RIP), mDNS, and link-local services.
    Never forwarded by routers.
  • 224.0.1.0/24 — Internetwork Control
    May be forwarded across routers. Used by certain global multicast services.
  • 232.0.0.0/8 — Source-Specific Multicast (SSM)
    Modern, efficient multicast model where the receiver specifies the source.
  • 233.0.0.0/8 — GLOP / Enterprise Multicast
    Legacy ASN-based multicast allocation system.
  • 233.252.0.0/24 — Documentation Multicast
    Similar to TEST-NET, but for multicast examples.
  • 239.0.0.0/8 — Administratively Scoped Multicast
    Private, internal multicast similar to RFC1918 for unicast.
    Should never be forwarded globally.

Each entry includes:

  • Range
  • Purpose
  • Scope
  • Typical use
  • Detailed notes

Perfect for:

  • Network engineers
  • CCNP/CCIE multicast studies
  • Enterprise network architecture
  • Documentation and diagrams
CIDRNameDetailed Notes
0.0.0.0/8This Network BlockUsed when a host does not yet know its IP. 0.0.0.0 as source = 'I don't have an IP yet'. Also used for DHCPDISCOVER and default-route representation. Never manually assigned; should not appear on routed networks.
0.0.0.0/32Default RouteRepresents 'anywhere' in routing tables. Not an assignable host address.
255.255.255.255/32Limited BroadcastBroadcast to local Layer 2 domain only. Never routed. Used for ARP, DHCP, discovery protocols. Should never appear on routed interfaces.
10.0.0.0/8Private IPv4 SpaceMassive internal-use block. Ideal for large enterprises, campus backbones, multi‑region networks. Routable internally, not globally. Commonly subnetted into /16, /20, /24. RFC1918.
172.16.0.0/12Private IPv4 SpaceMid‑sized private block. Often used for VPN pools, server farms, segmentation. Easier to avoid conflicts than 192.168/16. RFC1918.
192.168.0.0/16Private IPv4 SpaceMost common home/SMB network space. Frequently used for VLANs, SOHO networks. High collision risk when merging networks (VPNs, acquisitions). RFC1918.
169.254.0.0/16Link‑Local APIPAAuto‑assigned when DHCP fails. Never routed. Used for local‑only communication, mDNS, device discovery. Seeing these in logs indicates DHCP problems. RFC3927.
127.0.0.0/8Loopback RangeEntire /8 loops back to local host. Typically only 127.0.0.1 used, but all addresses are valid loopbacks. Critical for local testing & inter‑process communication. Packets should never appear on the wire. RFC1122.
100.64.0.0/10Carrier‑Grade NATUsed by ISPs for large scale NAT44 to preserve IPv4 space. Not for enterprise LAN use. Appearing internally indicates misconfiguration or ISP interference. RFC6598.
192.0.0.0/24IETF Protocol AssignmentsReserved for protocol level functionality, transition mechanisms, and experimental uses. Rarely appears in enterprise networks. RFC5736.
192.0.2.0/24TEST‑NET‑1Documentation & training examples. Must NOT be used in production networks. RFC5737.
198.51.100.0/24TEST‑NET‑2Documentation & training examples. Safe for examples; never routed publicly. RFC5737.
203.0.113.0/24TEST‑NET‑3Documentation & training examples. Used in textbooks, diagrams, labs. RFC5737.
198.18.0.0/15Benchmarking RangeUsed for performance testing of routers, firewalls, and other devices. Reserved for benchmark labs; not intended for general networking. RFC2544.
224.0.0.0/4Multicast RangeAll multicast traffic (IGMP, mDNS, routing protocols). 224.0.0.0 224.0.0.255 reserved for local‑network control. 239.0.0.0/8 for administratively scoped multicast.
240.0.0.0/4Reserved (Future Use)Experimental block. Not publicly routed. Historically unsupported, but modern OSes can route some of this block. Still considered reserved.
192.88.99.0/24Deprecated 6to4 RelayFormerly used for IPv6 transition. Deprecated and removed from global routing. Should not be used. RFC7526.
192.175.48.0/24AS112 SinkholeUsed for reverse‑DNS leaks and misconfigured private DNS queries. Operated by volunteer AS112 nodes to absorb misdirected traffic.
233.252.0.0/14Documentation MulticastTEST MULTICAST range for documentation. Never used in production multicast deployments. RFC6034.
255.0.0.0/8ReservedReserved for future definition. Not assignable. Not routed. Packets from this block indicate spoofing or misconfiguration.