Rowland penny
2020-May-21 12:07 UTC
[Samba] Fwd: DHCP Updates to DNS - Multiple Entries with Same IP
On 21/05/2020 12:22, Derek Cramer via samba wrote:> I had exactly the same issue with dual dhcp servers. I solved it by > modifying the script to do conditional updates. I.e. only add the A/PTR > entries if they are not already present.Now that is a good idea, why didn't I think of it ;-) I have identified a slight bug with the 'add' part, if you reboot a client and it releases the IP, then when the the client comes up and the script is run, it claims the update has failed, even though it has succeeded. I have a fix. The problem with the 'failover' is down to using '128' on both DC's, this leads to both of them replying to requests, I will update the wikipage to use '255' on the primary and '0' on the secondary. This should lead to only one (the primary) replying unless the primary goes down. Rowland
Matt Savin
2020-May-21 20:04 UTC
[Samba] Fwd: DHCP Updates to DNS - Multiple Entries with Same IP
I think you can continue to use '128' (good for load balancing, otherwise 255 is fine). I had the same issue, following dhcpd.conf entries fixed it (the last entry is important): one-lease-per-client true; deny duplicates; ignore-client-uids true; And it's not a bug, it's by design as is **REQUIRED** by the RFCs. Best regards, Matt On Thu, May 21, 2020 at 8:08 AM Rowland penny via samba < samba at lists.samba.org> wrote:> On 21/05/2020 12:22, Derek Cramer via samba wrote: > > I had exactly the same issue with dual dhcp servers. I solved it by > > modifying the script to do conditional updates. I.e. only add the A/PTR > > entries if they are not already present. > > Now that is a good idea, why didn't I think of it ;-) > > I have identified a slight bug with the 'add' part, if you reboot a > client and it releases the IP, then when the the client comes up and the > script is run, it claims the update has failed, even though it has > succeeded. I have a fix. > > The problem with the 'failover' is down to using '128' on both DC's, > this leads to both of them replying to requests, I will update the > wikipage to use '255' on the primary and '0' on the secondary. This > should lead to only one (the primary) replying unless the primary goes > down. > > Rowland > > > > -- > To unsubscribe from this list go to the following URL and read the > instructions: https://lists.samba.org/mailman/options/samba >
Rowland penny
2020-May-21 20:37 UTC
[Samba] Fwd: DHCP Updates to DNS - Multiple Entries with Same IP
On 21/05/2020 21:04, Matt Savin wrote:> I think you can continue to use '128' (good for load balancing, > otherwise 255 is fine). I had the same issue, following dhcpd.conf > entries fixed it (the last entry is important): > > one-lease-per-client? true; > deny ? ? ? ? ? ? ? ? ? ? ? ?? duplicates; > ignore-client-uids ? ?? true; > > And it's not a bug, it's by design as is **REQUIRED** by the RFCs.Perhaps 'bug' was the wrong word ;-) It is my understanding that with '128', both dhcp servers listen and reply to requests, with '255' only one server listens and replies. Rowland
Possibly Parallel Threads
- Fwd: DHCP Updates to DNS - Multiple Entries with Same IP
- How to disable dnsmasq from starting automatically with libvirtd
- Can't build 5.9 with KVM on a 6.3 host - DHCP hang?
- Client machine cannot acquire the IP from dhcp server
- kickstart: dracut-initqueue fails due to unresolvable hostname even though network config looks perfectly ok