Hi Kraishak, You do need to split up the pools that way and use classes (though I believe the classes are automatically created) but only if you use the "load-balancing" mode. If you stick to "hot-standby" then you won't need to do that. "load-balancing" is really not necessary (in my humble opinion) as in the event of a failure, any of your Kea servers need to be able to handle 100% of the client load and you could unknowingly get to a situation where that isn't the case only to find out during an outage. ISC DHCP didn't have a "hot-standby" mode so you were forced to load balance (which introduced problems with the sharing of addresses between the servers sometimes).
Thank you, Darren Ankney On Thu, Apr 20, 2023 at 1:20 AM Kraishak Mahtha <[email protected]> wrote: >> >> >> Hi Dareen, >> >> Thanks for sharing the answers, yes yesterday while I was exploring more >> about the Kea-HA, I came to know that if we use multithreading then we don't >> need to use a kea-control agent and I did try the test case it worked well >> for me. >> >> You can log kea-ctrl-agent.http in the kea-ctrl-agent config and probably >> kea-dhcp4.ha-hooks will contain the kea-dhcp4 perspective. >> >> --> ok sure >> >> >>In any case, after Kea loses contact with the other server it won't >> answer clients until max-unacked-clients is reached. -> Got it >> >> One more question regarding the load balancing HA mode, in the document >> (https://kea.readthedocs.io/en/kea-2.2.0/arm/hooks.html#supported-configurations) >> it says that >> >> However, it is not always clear to the operators that using the >> load-balancing mode requires manually splitting the address pools between >> two Kea instances using client classification, to preclude both servers from >> allocating the same address to different clients. Such a split is not needed >> in the hot-standby mode >> >> --->So do we need to manually split the scope in the load balancing >> configuration by associating the classes in HA mode for load balancing type >> like this ?` >> >> Config: > > "subnet4": [{ > > "subnet": "192.0.3.0/24", > "pools": [{ > "pool": "192.0.3.100 - 192.0.3.150", > "client-class": "HA_server1" > }, { > "pool": "192.0.3.200 - 192.0.3.250", > "client-class": "HA_server2" > }], > > "option-data": [{ > "name": "routers", > "data": "192.0.3.1" > }], >> >> Something like this: HA_Server1 and HA_Server2?` >> >> I am asking because I have around 5 to 6 DHCP pairs with hundreds of subnets >> configured on each failover peer in ISC DHCP. Most of the subnets have >> multiple scopes, ranging from 5 to 6 and with different ranges. For example, >> the first scope may have 17 IPs, the second 35, and the third around 200. >> This is in a spread-out environment where we use ISC. >> >> Generally, in ISC, we define the scopes and split percentages, and DHCP >> takes care of sharing the IPs between them. However, in Kea, there doesn't >> seem to be a similar mechanism, or I could be wrong. Could you please let me >> know if the process of manual splitting should be done in Kea when migrating >> from ISC to Kea? Or do we have any other configuration parameter that makes >> the Kea DHCP server automatically split the IPs 50-50% from all available >> scopes of the subnet? > > > Thanks > Kraishak -- ISC funds the development of this software with paid support subscriptions. Contact us at https://www.isc.org/contact/ for more information. To unsubscribe visit https://lists.isc.org/mailman/listinfo/kea-users. Kea-users mailing list [email protected] https://lists.isc.org/mailman/listinfo/kea-users
