Introduction to DHCPv6

Networking
Comments

Dynamic Host Configuration Protocol for IPv6 (DHCPv6) is just that: a protocol that can be used for host configuration, defined in RFC 8415. In this post I will introduce some basics of the protocol.

DHCPv6 protocol

A DHCPv6 message for client-server conversation consists of message type (1 byte), transaction ID (3 bytes) and variable number of variable-length DHCPv6 options.

DHCPv6 messages are sent using UDP as the transport protocol:

  • DHCPv6 servers and relay agents listen on port 547
  • DHCPv6 clients listen on port 546

DHCPv6 clients send messages to the link-scoped All_DHCP_Relay_Agents_and_Servers multicast address ff02::1:2. DHCPv6 client can also use unicast to reach a specific DHCPv6 server directly if the server has previously sent a message with the Server Unicast option (OPTION_UNICAST, 12) to the client.

Message types, with descriptions straight from RFC 8415 section 7.3:

  • Solicit (1): A client sends a Solicit message to locate servers.
  • Advertise (2): A server sends an Advertise message to indicate that it is available for DHCP service, in response to a Solicit message received from a client.
  • Request (3): A client sends a Request message to request configuration parameters, including addresses and/or delegated prefixes, from a specific server.
  • Confirm (4): A client sends a Confirm message to any available server to determine whether the addresses it was assigned are still appropriate to the link to which the client is connected.
  • Renew (5): A client sends a Renew message to the server that originally provided the client’s leases and configuration parameters to extend the lifetimes on the leases assigned to the client and to update other configuration parameters.
  • Rebind (6): A client sends a Rebind message to any available server to extend the lifetimes on the leases assigned to the client and to update other configuration parameters; this message is sent after a client receives no response to a Renew message.
  • Reply (7): A server sends a Reply message containing assigned leases and configuration parameters in response to a Solicit, Request, Renew, or Rebind message received from a client. A server sends a Reply message containing configuration parameters in response to an Information-request message. A server sends a Reply message in response to a Confirm message confirming or denying that the addresses assigned to the client are appropriate to the link to which the client is connected. A server sends a Reply message to acknowledge receipt of a Release or Decline message.
  • Release (8): A client sends a Release message to the server that assigned leases to the client to indicate that the client will no longer use one or more of the assigned leases.
  • Decline (9): A client sends a Decline message to a server to indicate that the client has determined that one or more addresses assigned by the server are already in use on the link to which the client is connected.
  • Reconfigure (10): A server sends a Reconfigure message to a client to inform the client that the server has new or updated configuration parameters and that the client is to initiate a Renew/Reply, Rebind/Reply, or Information-request/Reply transaction with the server in order to receive the updated information.
  • Information-request (11): A client sends an Information-request message to a server to request configuration parameters without the assignment of any leases to the client.
  • Relay-forward (12): A relay agent sends a Relay-forward message to relay messages to servers, either directly or through another relay agent. The received message — either a client message or a Relay-forward message from another relay agent — is encapsulated in an option in the Relay-forward message.
  • Relay-reply (13): A server sends a Relay-reply message to a relay agent containing a message that the relay agent delivers to a client. The Relay-reply message may be relayed by other relay agents for delivery to the destination relay agent. The server encapsulates the client message as an option in the Relay-reply message, which the relay agent extracts and relays to the client.

All values in the DHCPv6 message header and in the options are in network byte order (big-endian): the most significant byte first. I like this explicit specification as the secs field of DHCP was never clearly defined, and that allowed different implementations to have different endianness using it.

Transaction ID field in DHCPv6 message is 3 bytes, as opposed to 4 bytes in DHCP in IPv4.

DHCP Unique Identifier (DUID)

Each DHCPv6 client and server has a DUID. There are multiple DUID types defined and they are all of different size. DHCPv6 clients and servers must treat all DUIDs as opaque values and only compare them for equality.

Especially, client’s link-layer address (like MAC address) should not be attempted to be parsed from DUID. If link-layer address needs to be obtained, Client Link-Layer Address option (OPTION_CLIENT_LINKLAYER_ADDR, option code 79) defined in RFC 6939 should be used.

If a DHCPv6 client needs to target a specific DHCPv6 server when using multicast, it will use the server’s DUID in the Server Identifier option (OPTION_SERVERID, 2). Other servers will then ignore the message even though they all receive it.

Other DHCPv6-specific terminology

  • IA: Identity Association is a collection of leases assigned to a client
  • IA_NA: Identity Association for Non-temporary Addresses
  • IA_PD: Identity Association for Prefix Delegation
  • IA_TA: Identity Association for Temporary Addresses

Message exchange example

The demo setup:

  • DHCPv6 client is ISC DHCP client version 4.4.1 on Debian 11
  • DHCPv6 server is Windows Server 2022 DHCP service

Here is the message exchange example when the client connected to the network:

If you want to see the full packets, you can download the capture file here (or, see the appendix at the end of this post):

In packet 4 the client sent Router Solicitation ICMPv6 message as multicast to ff02::2 (All Routers Address) using the link-local address as the source, and in packet 5 the local subnet router responded with Router Advertisement message with the following details:

  • Prefix = 2001:db8:9876::1/64
  • Managed address configuration flag is set
  • Autonomous address-configuration flag is not set

The Autonomous address-configuration flag is not set, so the client does not use SLAAC (Stateless Address Autoconfiguration). The Managed address configuration flag instructs the client to use DHCPv6.

In DHCP (for IPv4) there is DORA (Discover, Offer, Request, ACK). In DHCPv6 there is SARR: Solicit, Advertise, Request, Reply:

  • Solicit in packet 6
    • Source address: client’s link-local address fe80::20c:29ff:fe67:427a
    • Source port: 546
    • Destination address: multicast address ff02::1:2 (All_DHCP_Relay_Agents_and_Servers)
    • Destination port: 547
    • Client DUID: 000100012ce275a7000c2967427a
    • Client requests a non-temporary address using IA_NA, and some usual options (DNS servers, domain search list, etc)
  • Advertise in packet 7
    • Source address: 2001:db8:9876::30 (the global unicast address of the DHCPv6 server)
    • Source port: 547
    • Destination address: fe80::20c:29ff:fe67:427a
    • Destination port: 546
    • Server DUID: 000100006498654c000c2978effd
    • Advertised IPv6 address: 2001:db8:9876:0:f284:9e6:7888:9700
    • Preferred lifetime: 240 seconds
    • T1 (renewal) value: 120 seconds
    • T2 (rebind) value: 192 seconds
    • DNS recursive name servers: 2606:4700:4700::1111 and 2606:4700:4700::1001
  • Request in packet 9
    • Addressing as in the Solicit message above
    • Client includes the Server Identifier option in the message to target it to the specific server (DUID)
  • Reply in packet 10
    • Addressing as in the Advertise message above

Note how the transaction ID is used in DHCPv6: For each message (except for retransmissions) the client creates a new random transaction ID, and the server must include the same ID in the response, for the client to process the message. There is no need for the client to hold on to the same transaction ID for any longer period of time when the message exchange has succeeded. Therefore the Solicit and Request messages had different transaction IDs.

In the server’s response messages there is no option for the default gateway for the client. Even though the client got its IPv6 address from the DHCPv6 server, it still got the default gateway information from the Router Advertisement message from the local subnet router. There is no subnet router option in DHCPv6.

In the example above the DHCPv6 client and server were in the same link, so there was no DHCPv6 relay needed.

In packets 19 and 20 there are also Renew and Reply packets. T1 was 120 seconds when the client received the Advertise message, so the client started renewal process after two minutes. The Renew message was still sent to the multicast address, and the server DUID was specified in the Server Identifier option.

Finally in packets 28 and 29 there are Release and Reply packets due to the client shutting down the interface.

This example showed a normal SARR process (Solicit, Advertise, Request, Reply), but there is also possibility for faster Solicit/Reply message exchange if both client and server supports the Rapid Commit option (OPTION_RAPID_COMMIT, 14).

This is how the DHCPv6 server logged the messages:

11000,11/11/23,19:25:59,DHCPV6 Solicit,2001:db8:9876:0:f284:9e6:7888:9700,,,14,000100012CE275A7000C2967427A,,,,,
11002,11/11/23,19:26:00,DHCPV6 Request,2001:db8:9876:0:f284:9e6:7888:9700,,,14,000100012CE275A7000C2967427A,,,,,
11004,11/11/23,19:28:00,DHCPV6 Renew,2001:db8:9876:0:f284:9e6:7888:9700,,,14,000100012CE275A7000C2967427A,,,,,
11007,11/11/23,19:29:05,DHCPV6 Release,2001:db8:9876:0:f284:9e6:7888:9700,,,14,000100012CE275A7000C2967427A,,,,,
11016,11/11/23,19:29:05,DHCPV6 client Deleted,2001:db8:9876:0:f284:9e6:7888:9700,,,14,000100012CE275A7000C2967427A,,,,,

The default configuration of the ISC DHCPv6 client used here does not have the client hostname configured. It can be added in /etc/dhcp/dhclient.conf if needed:

send fqdn.fqdn "testclient.domain.name";
or
send fqdn.fqdn = gethostname();

It will then be included in the DHCPv6 messages in DHCPv6 Client FQDN option (OPTION_FQDN, 39, defined in RFC 4704).

Compatibility

The elephant in the DHCPv6 room is that while DHCP in IPv4 world is used with basically all kinds of devices, in the IPv6 world there is one major operating system that doesn’t do DHCPv6: Android devices can only use SLAAC for address autoconfiguration.

Appendix: Packets from the capture

Here are the relevant packets (frames) as dissected by Wireshark:

Frame 4: 70 bytes on wire (560 bits), 70 bytes captured (560 bits)
Ethernet II, Src: VMware_67:42:7a (00:0c:29:67:42:7a), Dst: IPv6mcast_02 (33:33:00:00:00:02)
Internet Protocol Version 6, Src: fe80::20c:29ff:fe67:427a, Dst: ff02::2
Internet Control Message Protocol v6
    Type: Router Solicitation (133)
    Code: 0
    Checksum: 0xa353 [correct]
    [Checksum Status: Good]
    Reserved: 00000000
    ICMPv6 Option (Source link-layer address : 00:0c:29:67:42:7a)
        Type: Source link-layer address (1)
        Length: 1 (8 bytes)
        Link-layer address: VMware_67:42:7a (00:0c:29:67:42:7a)

Frame 5: 110 bytes on wire (880 bits), 110 bytes captured (880 bits)
Ethernet II, Src: PaloAltoNetw_80:58:10 (64:7c:e8:80:58:10), Dst: IPv6mcast_01 (33:33:00:00:00:01)
Internet Protocol Version 6, Src: fe80::667c:e8ff:fe80:5810, Dst: ff02::1
Internet Control Message Protocol v6
    Type: Router Advertisement (134)
    Code: 0
    Checksum: 0x89d5 [correct]
    [Checksum Status: Good]
    Cur hop limit: 64
    Flags: 0x80, Managed address configuration, Prf (Default Router Preference): Medium
        1... .... = Managed address configuration: Set
        .0.. .... = Other configuration: Not set
        ..0. .... = Home Agent: Not set
        ...0 0... = Prf (Default Router Preference): Medium (0)
        .... .0.. = ND Proxy: Not set
        .... ..0. = Reserved: 0
    Router lifetime (s): 600
    Reachable time (ms): 0
    Retrans timer (ms): 0
    ICMPv6 Option (Source link-layer address : 64:7c:e8:80:58:10)
        Type: Source link-layer address (1)
        Length: 1 (8 bytes)
        Link-layer address: PaloAltoNetw_80:58:10 (64:7c:e8:80:58:10)
    ICMPv6 Option (Prefix information : 2001:db8:9876::1/64)
        Type: Prefix information (3)
        Length: 4 (32 bytes)
        Prefix Length: 64
        Flag: 0x80, On-link flag(L)
            1... .... = On-link flag(L): Set
            .0.. .... = Autonomous address-configuration flag(A): Not set
            ..0. .... = Router address flag(R): Not set
            ...0 0000 = Reserved: 0
        Valid Lifetime: 300 (5 minutes)
        Preferred Lifetime: 150 (2 minutes, 30 seconds)
        Reserved
        Prefix: 2001:db8:9876::1

Frame 6: 118 bytes on wire (944 bits), 118 bytes captured (944 bits)
Ethernet II, Src: VMware_67:42:7a (00:0c:29:67:42:7a), Dst: IPv6mcast_01:00:02 (33:33:00:01:00:02)
Internet Protocol Version 6, Src: fe80::20c:29ff:fe67:427a, Dst: ff02::1:2
User Datagram Protocol, Src Port: 546, Dst Port: 547
DHCPv6
    Message type: Solicit (1)
    Transaction ID: 0x9627dc
    Client Identifier
        Option: Client Identifier (1)
        Length: 14
        DUID: 000100012ce275a7000c2967427a
        DUID Type: link-layer address plus time (1)
        Hardware type: Ethernet (1)
        DUID Time: Nov 11, 2023 19:25:59.000000000 FLE Standard Time
        Link-layer address: 00:0c:29:67:42:7a
        Link-layer address (Ethernet): VMware_67:42:7a (00:0c:29:67:42:7a)
    Option Request
        Option: Option Request (6)
        Length: 8
        Requested Option code: DNS recursive name server (23)
        Requested Option code: Domain Search List (24)
        Requested Option code: Client Fully Qualified Domain Name (39)
        Requested Option code: Simple Network Time Protocol Server (31)
    Elapsed time
        Option: Elapsed time (8)
        Length: 2
        Elapsed time: 0ms
    Identity Association for Non-temporary Address
        Option: Identity Association for Non-temporary Address (3)
        Length: 12
        IAID: 2967427a
        T1: 3600
        T2: 5400

Frame 7: 182 bytes on wire (1456 bits), 182 bytes captured (1456 bits)
Ethernet II, Src: VMware_78:ef:07 (00:0c:29:78:ef:07), Dst: VMware_67:42:7a (00:0c:29:67:42:7a)
Internet Protocol Version 6, Src: 2001:db8:9876::30, Dst: fe80::20c:29ff:fe67:427a
User Datagram Protocol, Src Port: 547, Dst Port: 546
DHCPv6
    Message type: Advertise (2)
    Transaction ID: 0x9627dc
    Server Identifier
        Option: Server Identifier (2)
        Length: 14
        DUID: 000100006498654c000c2978effd
        DUID Type: link-layer address plus time (1)
        Hardware type: NET/ROM pseudo (0)
        DUID Time: Jun 24, 2053 19:03:24.000000000 FLE Summer Time
        Link-layer address: 000c2978effd
    Client Identifier
        Option: Client Identifier (1)
        Length: 14
        DUID: 000100012ce275a7000c2967427a
        DUID Type: link-layer address plus time (1)
        Hardware type: Ethernet (1)
        DUID Time: Nov 11, 2023 19:25:59.000000000 FLE Standard Time
        Link-layer address: 00:0c:29:67:42:7a
        Link-layer address (Ethernet): VMware_67:42:7a (00:0c:29:67:42:7a)
    Identity Association for Non-temporary Address
        Option: Identity Association for Non-temporary Address (3)
        Length: 40
        IAID: 2967427a
        T1: 120
        T2: 192
        IA Address
            Option: IA Address (5)
            Length: 24
            IPv6 address: 2001:db8:9876:0:f284:9e6:7888:9700
            Preferred lifetime: 240
            Valid lifetime: 1800
    DNS recursive name server
        Option: DNS recursive name server (23)
        Length: 32
         1 DNS server address: 2606:4700:4700::1111
         2 DNS server address: 2606:4700:4700::1001

Frame 9: 164 bytes on wire (1312 bits), 164 bytes captured (1312 bits)
Ethernet II, Src: VMware_67:42:7a (00:0c:29:67:42:7a), Dst: IPv6mcast_01:00:02 (33:33:00:01:00:02)
Internet Protocol Version 6, Src: fe80::20c:29ff:fe67:427a, Dst: ff02::1:2
User Datagram Protocol, Src Port: 546, Dst Port: 547
DHCPv6
    Message type: Request (3)
    Transaction ID: 0xb56bcd
    Client Identifier
        Option: Client Identifier (1)
        Length: 14
        DUID: 000100012ce275a7000c2967427a
        DUID Type: link-layer address plus time (1)
        Hardware type: Ethernet (1)
        DUID Time: Nov 11, 2023 19:25:59.000000000 FLE Standard Time
        Link-layer address: 00:0c:29:67:42:7a
        Link-layer address (Ethernet): VMware_67:42:7a (00:0c:29:67:42:7a)
    Server Identifier
        Option: Server Identifier (2)
        Length: 14
        DUID: 000100006498654c000c2978effd
        DUID Type: link-layer address plus time (1)
        Hardware type: NET/ROM pseudo (0)
        DUID Time: Jun 24, 2053 19:03:24.000000000 FLE Summer Time
        Link-layer address: 000c2978effd
    Option Request
        Option: Option Request (6)
        Length: 8
        Requested Option code: DNS recursive name server (23)
        Requested Option code: Domain Search List (24)
        Requested Option code: Client Fully Qualified Domain Name (39)
        Requested Option code: Simple Network Time Protocol Server (31)
    Elapsed time
        Option: Elapsed time (8)
        Length: 2
        Elapsed time: 0ms
    Identity Association for Non-temporary Address
        Option: Identity Association for Non-temporary Address (3)
        Length: 40
        IAID: 2967427a
        T1: 3600
        T2: 5400
        IA Address
            Option: IA Address (5)
            Length: 24
            IPv6 address: 2001:db8:9876:0:f284:9e6:7888:9700
            Preferred lifetime: 7200
            Valid lifetime: 7500

Frame 10: 182 bytes on wire (1456 bits), 182 bytes captured (1456 bits)
Ethernet II, Src: VMware_78:ef:07 (00:0c:29:78:ef:07), Dst: VMware_67:42:7a (00:0c:29:67:42:7a)
Internet Protocol Version 6, Src: 2001:db8:9876::30, Dst: fe80::20c:29ff:fe67:427a
User Datagram Protocol, Src Port: 547, Dst Port: 546
DHCPv6
    Message type: Reply (7)
    Transaction ID: 0xb56bcd
    Server Identifier
        Option: Server Identifier (2)
        Length: 14
        DUID: 000100006498654c000c2978effd
        DUID Type: link-layer address plus time (1)
        Hardware type: NET/ROM pseudo (0)
        DUID Time: Jun 24, 2053 19:03:24.000000000 FLE Summer Time
        Link-layer address: 000c2978effd
    Client Identifier
        Option: Client Identifier (1)
        Length: 14
        DUID: 000100012ce275a7000c2967427a
        DUID Type: link-layer address plus time (1)
        Hardware type: Ethernet (1)
        DUID Time: Nov 11, 2023 19:25:59.000000000 FLE Standard Time
        Link-layer address: 00:0c:29:67:42:7a
        Link-layer address (Ethernet): VMware_67:42:7a (00:0c:29:67:42:7a)
    Identity Association for Non-temporary Address
        Option: Identity Association for Non-temporary Address (3)
        Length: 40
        IAID: 2967427a
        T1: 120
        T2: 192
        IA Address
            Option: IA Address (5)
            Length: 24
            IPv6 address: 2001:db8:9876:0:f284:9e6:7888:9700
            Preferred lifetime: 240
            Valid lifetime: 1800
    DNS recursive name server
        Option: DNS recursive name server (23)
        Length: 32
         1 DNS server address: 2606:4700:4700::1111
         2 DNS server address: 2606:4700:4700::1001

Frame 19: 164 bytes on wire (1312 bits), 164 bytes captured (1312 bits)
Ethernet II, Src: VMware_67:42:7a (00:0c:29:67:42:7a), Dst: IPv6mcast_01:00:02 (33:33:00:01:00:02)
Internet Protocol Version 6, Src: fe80::20c:29ff:fe67:427a, Dst: ff02::1:2
User Datagram Protocol, Src Port: 546, Dst Port: 547
DHCPv6
    Message type: Renew (5)
    Transaction ID: 0xf75aaa
    Client Identifier
        Option: Client Identifier (1)
        Length: 14
        DUID: 000100012ce275a7000c2967427a
        DUID Type: link-layer address plus time (1)
        Hardware type: Ethernet (1)
        DUID Time: Nov 11, 2023 19:25:59.000000000 FLE Standard Time
        Link-layer address: 00:0c:29:67:42:7a
        Link-layer address (Ethernet): VMware_67:42:7a (00:0c:29:67:42:7a)
    Server Identifier
        Option: Server Identifier (2)
        Length: 14
        DUID: 000100006498654c000c2978effd
        DUID Type: link-layer address plus time (1)
        Hardware type: NET/ROM pseudo (0)
        DUID Time: Jun 24, 2053 19:03:24.000000000 FLE Summer Time
        Link-layer address: 000c2978effd
    Option Request
        Option: Option Request (6)
        Length: 8
        Requested Option code: DNS recursive name server (23)
        Requested Option code: Domain Search List (24)
        Requested Option code: Client Fully Qualified Domain Name (39)
        Requested Option code: Simple Network Time Protocol Server (31)
    Elapsed time
        Option: Elapsed time (8)
        Length: 2
        Elapsed time: 0ms
    Identity Association for Non-temporary Address
        Option: Identity Association for Non-temporary Address (3)
        Length: 40
        IAID: 2967427a
        T1: 3600
        T2: 5400
        IA Address
            Option: IA Address (5)
            Length: 24
            IPv6 address: 2001:db8:9876:0:f284:9e6:7888:9700
            Preferred lifetime: 7200
            Valid lifetime: 7500

Frame 20: 182 bytes on wire (1456 bits), 182 bytes captured (1456 bits)
Ethernet II, Src: VMware_78:ef:07 (00:0c:29:78:ef:07), Dst: VMware_67:42:7a (00:0c:29:67:42:7a)
Internet Protocol Version 6, Src: 2001:db8:9876::30, Dst: fe80::20c:29ff:fe67:427a
User Datagram Protocol, Src Port: 547, Dst Port: 546
DHCPv6
    Message type: Reply (7)
    Transaction ID: 0xf75aaa
    Server Identifier
        Option: Server Identifier (2)
        Length: 14
        DUID: 000100006498654c000c2978effd
        DUID Type: link-layer address plus time (1)
        Hardware type: NET/ROM pseudo (0)
        DUID Time: Jun 24, 2053 19:03:24.000000000 FLE Summer Time
        Link-layer address: 000c2978effd
    Client Identifier
        Option: Client Identifier (1)
        Length: 14
        DUID: 000100012ce275a7000c2967427a
        DUID Type: link-layer address plus time (1)
        Hardware type: Ethernet (1)
        DUID Time: Nov 11, 2023 19:25:59.000000000 FLE Standard Time
        Link-layer address: 00:0c:29:67:42:7a
        Link-layer address (Ethernet): VMware_67:42:7a (00:0c:29:67:42:7a)
    Identity Association for Non-temporary Address
        Option: Identity Association for Non-temporary Address (3)
        Length: 40
        IAID: 2967427a
        T1: 120
        T2: 192
        IA Address
            Option: IA Address (5)
            Length: 24
            IPv6 address: 2001:db8:9876:0:f284:9e6:7888:9700
            Preferred lifetime: 240
            Valid lifetime: 1800
    DNS recursive name server
        Option: DNS recursive name server (23)
        Length: 32
         1 DNS server address: 2606:4700:4700::1111
         2 DNS server address: 2606:4700:4700::1001

Frame 28: 164 bytes on wire (1312 bits), 164 bytes captured (1312 bits)
Ethernet II, Src: VMware_67:42:7a (00:0c:29:67:42:7a), Dst: IPv6mcast_01:00:02 (33:33:00:01:00:02)
Internet Protocol Version 6, Src: fe80::20c:29ff:fe67:427a, Dst: ff02::1:2
User Datagram Protocol, Src Port: 546, Dst Port: 547
DHCPv6
    Message type: Release (8)
    Transaction ID: 0xa61b60
    Client Identifier
        Option: Client Identifier (1)
        Length: 14
        DUID: 000100012ce275a7000c2967427a
        DUID Type: link-layer address plus time (1)
        Hardware type: Ethernet (1)
        DUID Time: Nov 11, 2023 19:25:59.000000000 FLE Standard Time
        Link-layer address: 00:0c:29:67:42:7a
        Link-layer address (Ethernet): VMware_67:42:7a (00:0c:29:67:42:7a)
    Server Identifier
        Option: Server Identifier (2)
        Length: 14
        DUID: 000100006498654c000c2978effd
        DUID Type: link-layer address plus time (1)
        Hardware type: NET/ROM pseudo (0)
        DUID Time: Jun 24, 2053 19:03:24.000000000 FLE Summer Time
        Link-layer address: 000c2978effd
    Option Request
        Option: Option Request (6)
        Length: 8
        Requested Option code: DNS recursive name server (23)
        Requested Option code: Domain Search List (24)
        Requested Option code: Client Fully Qualified Domain Name (39)
        Requested Option code: Simple Network Time Protocol Server (31)
    Elapsed time
        Option: Elapsed time (8)
        Length: 2
        Elapsed time: 0ms
    Identity Association for Non-temporary Address
        Option: Identity Association for Non-temporary Address (3)
        Length: 40
        IAID: 2967427a
        T1: 0
        T2: 0
        IA Address
            Option: IA Address (5)
            Length: 24
            IPv6 address: 2001:db8:9876:0:f284:9e6:7888:9700
            Preferred lifetime: 0
            Valid lifetime: 0

Frame 29: 146 bytes on wire (1168 bits), 146 bytes captured (1168 bits)
Ethernet II, Src: VMware_78:ef:07 (00:0c:29:78:ef:07), Dst: VMware_67:42:7a (00:0c:29:67:42:7a)
Internet Protocol Version 6, Src: 2001:db8:9876::30, Dst: fe80::20c:29ff:fe67:427a
User Datagram Protocol, Src Port: 547, Dst Port: 546
DHCPv6
    Message type: Reply (7)
    Transaction ID: 0xa61b60
    Server Identifier
        Option: Server Identifier (2)
        Length: 14
        DUID: 000100006498654c000c2978effd
        DUID Type: link-layer address plus time (1)
        Hardware type: NET/ROM pseudo (0)
        DUID Time: Jun 24, 2053 19:03:24.000000000 FLE Summer Time
        Link-layer address: 000c2978effd
    Client Identifier
        Option: Client Identifier (1)
        Length: 14
        DUID: 000100012ce275a7000c2967427a
        DUID Type: link-layer address plus time (1)
        Hardware type: Ethernet (1)
        DUID Time: Nov 11, 2023 19:25:59.000000000 FLE Standard Time
        Link-layer address: 00:0c:29:67:42:7a
        Link-layer address (Ethernet): VMware_67:42:7a (00:0c:29:67:42:7a)
    Identity Association for Non-temporary Address
        Option: Identity Association for Non-temporary Address (3)
        Length: 40
        IAID: 2967427a
        T1: 0
        T2: 0
        IA Address
            Option: IA Address (5)
            Length: 24
            IPv6 address: 2001:db8:9876:0:f284:9e6:7888:9700
            Preferred lifetime: 0
            Valid lifetime: 0
Updated: November 18, 2023 — 16:41
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