2.2.1.1.20 FSM_STATE

  • Article

The FSM_STATE enumeration defines a set of possible values representing various failover relationship states on a DHCPv4 server. For additional information about server state transitions, see [IETF-DHCPFOP-12], section 9.2.

  typedef enum _FSM_STATE{
      NO_STATE = 0x00000000,
      INIT,
      STARTUP,
      NORMAL,
      COMMUNICATION_INT,
      PARTNER_DOWN,
      POTENTIAL_CONFLICT,
      CONFLICT_DONE,
      RESOLUTION_INT,
      RECOVER,
      RECOVER_WAIT,
      RECOVER_DONE,
  } FSM_STATE;

NO_STATE: This value means that no state is configured for the DHCPv4 failover relationship.

INIT: This value means that the failover relationship on the DHCPv4 server is in the initializing state.

STARTUP: This value means that each server participating in the failover relationship moves into the STARTUP state after initializing itself. The STARTUP state enables a server to probe its partner server, before starting DHCP client service.

NORMAL: This value means that each server services DHCPDISCOVER messages [RFC2131] and all other DHCP requests, other than DHCPREQUEST/RENEWAL or DHCPREQUEST/REBINDING requests from the client set, as defined by the load balancing algorithm specified in [RFC3074]. Each server services DHCPREQUEST/RENEWAL or DHCPDISCOVER/REBINDING requests from any client.

COMMUNICATION_INT: This value means that each server in a failover relationship is operating independently in the COMMUNICATION_INT state, but neither assumes that its partner is not operating. The partner server might be operating and simply unable to communicate with this server, or it might not be operating at all.

PARTNER_DOWN: This value means that when operating in the PARTNER_DOWN state, a server assumes that its partner is not currently operating.

POTENTIAL_CONFLICT: This value indicates that the failover relationship between two DHCP servers is attempting to re-establish itself.

CONFLICT_DONE: This value indicates that during the process where two servers in a failover relationship attempt reintegration with each other, the primary server has received all updates from the secondary server.

RESOLUTION_INT: This value indicates that the two servers in a failover relationship were attempting reintegration with each other in the POTENTIAL_CONFLICT state, but communications failed prior to completion of the reintegration.

RECOVER: This value indicates that a server in a failover relationship has no information in its stable storage facility or that it is reintegrating with a server in the PARTNER_DOWN state after it has been down.

RECOVER_WAIT: This value means that the DHCPv4 server waits for a time period equal to maximum client lead time (MCLT) before moving to the RECOVER_DONE state.

RECOVER_DONE: This value enables an interlocked transition of one server from the RECOVER state and another server from the PARTNER_DOWN or COMMUNICATION-INT state to the NORMAL state.