Lease controls
Change the client’s path
RFC 2131 defaults T1 to 50% and T2 to 87.5% of the lease. Servers can supply different values.
Initialization
Local server pathDORA creates the binding
- 1Client → networkDHCPDISCOVER
Client broadcasts because it does not yet know a server or usable address.
- 2Server → clientDHCPOFFER
A server proposes an address, lease duration, and configuration options.
- 3Client → serversDHCPREQUEST
The client identifies the offer it selected so other servers can withdraw theirs.
- 4Server → clientDHCPACKNOWLEDGE
The selected server commits the binding; the client records the lease and timers.
8 hours from ACK to expiry
0BOUND
4 hoursT1 · RENEW
7 hoursT2 · REBIND
8 hoursEXPIRY
The client returns to BOUND at T1
The client unicasts DHCPREQUEST to the leasing server at 4 hours. A DHCPACK extends the lease and supplies new timers.