3.1.5.2 Receiving a DHCP Failover BNDUPD Message

The BNDUPD message MUST be processed to extract all lease updates. Each lease update SHOULD be processed as described in the following table. The table specifies which options are mandatory to include in the BNDUPD message corresponding to each IP address state.

Option

ACTIVE

EXPIRED

RELEASED

FREE/BACKUP

ABANDONED

Assigned IP Address

MUST

MUST

MUST

MUST

MUST

Binding Status

MUST

MUST

MUST

MUST

MUST

IP-Flags

MUST

MUST

MUST

MUST

MUST

Subnet Mask

MUST

MUST

MUST

MUST

MUST

Client Hardware Address

MUST

MUST

MUST

MUST NOT

MUST

Client Last Transaction Time

MUST

MUST

MUST

MUST NOT

MAY

Lease Expiration Time

MUST

MAY

MAY

MUST NOT

MAY

Potential Expiration Time

MUST

MAY

MAY

MUST NOT

MAY

DDNS

MAY

MAY

MAY

MUST NOT

MAY

Start Time of State

MAY

MAY

MAY

MUST NOT

MAY

Client Identifier

MAY

MAY

MAY

MUST NOT

MAY

Client Request Options

MAY

MAY

MAY

MUST NOT

MAY

Client Reply Options

MAY

MAY

MAY

MUST NOT

MAY

Client Name

SHOULD

SHOULD

SHOULD

MUST NOT

SHOULD

Client Description

SHOULD

SHOULD

SHOULD

MUST NOT

SHOULD

Client Server IP

SHOULD

SHOULD

SHOULD

MUST NOT

SHOULD

Client Server Name

SHOULD

SHOULD

SHOULD

MUST NOT

SHOULD

Client Type

SHOULD

SHOULD

SHOULD

MUST NOT

SHOULD

Client NAP Status

SHOULD

SHOULD

SHOULD

MUST NOT

SHOULD

Client NAP Probation Time

SHOULD

SHOULD

SHOULD

MUST NOT

SHOULD

Client NAP Capable

SHOULD

SHOULD

SHOULD

MUST NOT

SHOULD

Client Policy

SHOULD

SHOULD

SHOULD

MUST NOT

SHOULD

If the lease update does not contain all of the mandatory options corresponding to the IP Address state as indicated by the Binding Status option of the lease update, the DHCP server MUST reject that lease update with reject reason 3: Missing Binding Information.

When accepting the lease update, the rules specified in [IETF-DHCPFOP-12] section 7.1.2 and the first figure depicted in [IETF-DHCPFOP-12] section 7.1.3 MUST be followed.

The Binding Status option and the IP-Flags option values MUST be interpreted as specified in section 3.1.4.2.

If the IP-Flag option value of the lease update has the FAILOVER_DELETED_COMM_DOWN bit set, the validations specified in the preceding paragraphs are skipped.

When a BNDUPD message with an IP address state set to FREE or BACKUP is received, and there exists a DHCPv4Reservation ADM element corresponding to that IP address, the DHCP server MUST reject that lease update with reject reason 15: Outdated Binding Information.  

In a BNDUPD message contains multiple lease updates after processing 16 lease updates, the remaining lease updates are ignored.

The DHCP server MUST send a BNDACK message corresponding to the received BNDUPD message as described in [IETF-DHCPFOP-12] section 7.2.1. When multiple lease updates are packed in a single BNDUPD message, the order of the assigned IP address option in the corresponding BNDACK message MUST be the same as the order for that same option in the BNDUPD message.