IPv6 Neighbor Discovery Utility

IPv6 Solicited-Node Multicast Calculator

Calculate the IPv6 solicited-node multicast address from any IPv6 address. Extract the low-order 24 bits, build the FF02::1:FF00:0/104 multicast address and calculate the corresponding Ethernet 33:33:FF multicast MAC.

✓ Last 24 Bits ✓ FF02::1:FF00:0/104 ✓ Ethernet Multicast ✓ Neighbor Discovery ✓ DAD ✓ Compressed IPv6

SNM

Solicited-Node Multicast Calculation

● Ready

IPv6 Unicast / Anycast Address Enter a hexadecimal IPv6 address in compressed or expanded form.

Hexadecimal Display

IPv6 Output Format

Calculation rule: take only the low-order 24 bits of the IPv6 address and append those bits to the fixed 104-bit solicited-node prefix FF02::1:FF00:0/104. The corresponding Ethernet multicast address begins with 33:33:FF followed by those same three low-order bytes.

Solicited-Node Multicast Result Calculated

Solicited-Node Multicast Address —

Input IPv6 —

Last 24 Bits —

Last 3 Bytes —

Low 24-bit Value —

Multicast Prefix —

Solicited-Node IPv6 —

Ethernet Multicast —

IPv6 Scope —

Multicast Type —

Input Expanded —

Result Expanded —

Status —

Step-by-Step Calculation —

Bit / Byte Extraction —

Ethernet Mapping —

Validation & Notes —

What Is an IPv6 Solicited-Node Multicast Address?

A solicited-node multicast address is an IPv6 multicast address associated with the low-order 24 bits of an IPv6 unicast or anycast address. IPv6 Neighbor Discovery uses these addresses instead of relying on an IPv4-style broadcast mechanism.

The solicited-node multicast range uses the fixed prefix FF02::1:FF00:0/104.

Solicited-Node Multicast Formula

Fixed prefix:

FF02::1:FF00:0/104

Take:
Low-order 24 bits of IPv6 address

Then:

Solicited-Node Address =
FF02::1:FFxx:xxxx

Example Calculation

IPv6 Address:

2001:DB8::1234:5678

Expanded ending:

...:1234:5678

Last 24 bits:

34 56 78

Solicited-node multicast:

FF02::1:FF34:5678

Ethernet multicast:

33:33:FF:34:56:78

Why Only the Last 24 Bits?

The solicited-node prefix occupies the upper 104 bits of the resulting 128-bit multicast address. The remaining 24 bits come directly from the low-order 24 bits of the associated IPv6 address.

128 total IPv6 bits

104 fixed multicast bits
+
24 copied address bits
=
128 bits

Solicited-Node Multicast Prefix

FF02:0000:0000:0000:0000:0001:FF00:0000
                                      ↑
                                fixed /104 prefix

The value FF identifies an IPv6 multicast address. The 02 scope value means link-local scope.

IPv6 Neighbor Discovery

Neighbor Discovery Protocol uses ICMPv6 messages to discover neighboring nodes, routers, prefixes and link-layer addresses. Neighbor Solicitation messages can be sent to a target’s solicited-node multicast address.

This greatly reduces the number of hosts required to inspect a discovery request compared with sending a frame to every system on the link.

Solicited-Node Ethernet Multicast Address

On Ethernet, the solicited-node IPv6 multicast address maps to a multicast MAC address beginning with 33:33.

IPv6 solicited-node:

FF02::1:FF34:5678

Low 32 multicast bits:

FF 34 56 78

Ethernet mapping:

33:33:FF:34:56:78

For solicited-node addresses specifically, the resulting Ethernet address therefore has the recognizable prefix 33:33:FF.

Solicited-Node Address for IPv6 ::1

IPv6:

::1

Low 24 bits:

00:00:01

Solicited-node:

FF02::1:FF00:1

Ethernet:

33:33:FF:00:00:01

Duplicate Address Detection

IPv6 Duplicate Address Detection can use Neighbor Solicitation messages before an address is fully assigned to an interface. The target address’s solicited-node multicast group is involved in determining whether another node is already using the address.

Solicited-Node vs All-Nodes Multicast

Address	Purpose	Scope
FF02::1	All IPv6 nodes on the link	Link-local
FF02::2	All IPv6 routers on the link	Link-local
FF02::1:FFxx:xxxx	Solicited-node multicast	Link-local

Can Multiple IPv6 Addresses Share a Solicited-Node Group?

Yes. Because only 24 bits of the original IPv6 address are copied into the solicited-node multicast address, different IPv6 addresses with the same final 24 bits map to the same solicited-node multicast group.

2001:DB8:1::34:5678
2001:DB8:2::34:5678

Both end in:
34:56:78

Both map to:

FF02::1:FF34:5678

IPv6 Solicited-Node Multicast Calculator FAQs

How do I calculate an IPv6 solicited-node multicast address?

Take the last 24 bits of the IPv6 unicast or anycast address and append them to the fixed FF02::1:FF00:0/104 prefix.

What is the solicited-node multicast prefix?

The fixed prefix is FF02::1:FF00:0/104.

How many bits are copied from the IPv6 address?

Exactly 24 low-order bits, equivalent to the final three bytes.

What Ethernet MAC is used for a solicited-node multicast address?

For FF02::1:FFxx:xxxx, the Ethernet multicast address becomes 33:33:FF:xx:xx:xx.

What is the solicited-node multicast address for 2001:db8::1?

The final 24 bits are 00:00:01, so the resulting solicited-node multicast address is FF02::1:FF00:1.

Is a solicited-node multicast address link-local?

Yes. Its FF02 multicast scope is link-local.

Why does IPv6 use solicited-node multicast?

It lets Neighbor Discovery target a much smaller multicast group instead of sending discovery traffic to every node on the local link.

Can two IPv6 addresses have the same solicited-node address?

Yes. Any IPv6 addresses sharing the same final 24 bits produce the same solicited-node multicast address.