Differences

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--- infoblox_nios:dhcp [2025/05/13 15:23] – [Failover Associations] bstafford
+++ infoblox_nios:dhcp [2026/03/24 21:22] (current) – [Performance] bstafford
@@ Line 18: / Line 18: @@
   * Datasheet figures for DHCP LPS are based on full DORA with no ping before offer or DDNS.
   * Reporting of actual LPS being served is based on ACKs to cover renews.
+===== Moving Leases =====
+If you update a subnet to use a different DHCP server, the existing leases will not move until they renew. If the server that issued the lease is no longer valid (because you forced it over to member2) than it shouldn't respond at the T1 timer, and should renew on the new server when it sends a discover at the T2 timer.
+If the servers are in a failover pair and you are changing the balancing, you have to wait until the MCLT expires to take effect.
 ===== DHCP Hub-Spoke =====
@@ Line 49: / Line 54: @@
   * Free: The lease is available for clients to use.
   * Active: The lease is currently in use by a DHCP client.
-  * Static: The lease is a fixed address lease.
+  * Static: The lease is a fixed address lease. (enable under Grid DHCP Properties, General, Advanced)
   * Expired: The lease was in use, but the DHCP client never renewed it, so it is no longer valid.
   * Released: The DHCP client returned the lease to the appliance.
   * Abandoned: The appliance cannot lease this IP address because the appliance received a response when pinging the address.
   * Backup: Lease belongs to the secondary peer in a DHCP fail over relationship.
+===== Fixed Address Lease =====
+Under Grid DHCP Properties, General, Advanced.
+Fixed Address Lease. Without this feature enabled, there is no logging of leases assigned to fixed addresses and they cannot be tracked.
 ===== Primary VS Secondary =====
 If you have a DHCP Fail-over Association (FOA), one member will be "primary" and the other "secondary". For users, it makes no difference which is which assuming that the admin is following best-practice and using balanced distribution for the FOA. MAC address hash is used to determine which server responds.
@@ Line 193: / Line 203: @@
 The new behaviour is for DHCP filters to use AND logic.
+For DHCP, you can use Option 77 (User Class Identifier). This allows you to define a "string" ID on the client (windows or Linux) and this will be passed onto DCHP server during request. The DHCP server can then use that in a DCHP Option filter to ensure only clients presenting that ID will get issued a lease. The use case would be where you have a subnet and range that needs to issue IP's normally but a specific sub-set should only be issued to a specific group of servers (e.g. Database servers). You would create a range for that use case and apply the option filter. Why would you want to do this? Possibly for creating known firewall rules.
 ===== DHCP Version =====
 NIOS uses ISC DHCP. NIOS-X uses Kea.
+The following is from NIOS 9.0.7
 For NIOS, the version of ISC DHCP is printed to syslog when the DHCP service is restarted