DHCP Failover State
Configuration > Networking > DHCP Failover State
EdgeConnect appliances can act as a DHCP server for clients on the LAN side. DHCP failover allows redundancy by creating failover groups when two appliances are combined in an HA configuration. DHCP failover also provides stability if one EdgeConnect appliance dies by allowing the other EdgeConnect HA pair to take over as the DHCP server. To do so, the primary and secondary servers must be completely synchronized so that each server can reply on the other if one fails.
This tab displays the DHCP failover peer states of each server for troubleshooting purposes.
DHCP Failover State Fields
| Field | Description |
|---|---|
| Appliance | Name of the EdgeConnect appliance that is part of the DHCP failover configuration. |
| Failover Group Name | Failover group name that is the same for all the tagged and untagged interfaces corresponding to one physical interface. |
| My State | Failover endpoint state of the selected primary appliance. The states are: Normal, Communications-Interrupted, Partner-Down, Recover, Recover-wait, Recover-done. |
| My State Time | Date and time when the selected appliance’s DHCP server entered the specified state in the table. |
| Partner State | Failover endpoint state of the partner appliance. The states are: Normal, Communications-Interrupted, Partner-Down, Recover, Recover-wait, Recover-done. |
| Partner State Time | Date and time when the partner appliance entered the specified state in the table. |
| MCLT | Maximum client lead time: the maximum amount of time that one server can extend a lease for a client’s binding beyond the time known by the partner. |
DHCP Failover State Descriptions
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Normal: Both EdgeConnect DHCP servers are exchanging keepalives correctly and DHCP bindings are Synchronized.
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Communication-Interrupted: Each EdgeConnect is unable to exchange DHCP failover messages and does service DHCP requests independently. In this state, each EdgeConnect assumes that the partner EdgeConnect is not down, but only unable to exchange failover messages.
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Recover: The local EdgeConnect is trying to establish full synchronization of DHCP bindings with the previously down EdgeConnect. In this state, EdgeConnect does not serve any DHCP requests until the DHCP bindings are fully synchronized between them.
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Recover-wait: The DHCP server is waiting for a period equal to the Maximum Client Lead Time (MCLT) before transitioning to the “recover-done” state. During this time, the server is preparing to synchronize its lease database with its peer server so as to avoid any inconsistencies.
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Recover-done: EdgeConnects enter this state after recovering from a communication failure and completing the synchronization of DHCP bindings. EdgeConnects transition to this state after they recover state but prior to the normal state.
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Unknown: This indicates the peer state is unreachable or has not received any responses from the peer for the amount of Max Response Delay timer.