Send dhcp-users mailing list submissions to
dhcp-users@lists.isc.org
To subscribe or unsubscribe via the World Wide Web, visit
https://lists.isc.org/mailman/listinfo/dhcp-users
or, via email, send a message with subject or body 'help' to
dhcp-users-requ...@lists.isc.org
You can reach the person managing the list at
dhcp-users-ow...@lists.isc.org
When replying, please edit your Subject line so it is more specific
than "Re: Contents of dhcp-users digest..."
Today's Topics:
1. Re: dhcpd (failover peer setup) going and staying in failover
state (Nathan H?sken)
2. How to sync a Linux secondary DHCP server? (Sandra Schlichting)
----------------------------------------------------------------------
Message: 1
Date: Sun, 29 Jul 2018 17:18:04 -0400
From: Nathan H?sken <nat...@wintercloud.de>
To: Users of ISC DHCP <dhcp-users@lists.isc.org>
Subject: Re: dhcpd (failover peer setup) going and staying in failover
state
Message-ID:
<geoR3huRZ-3fVv-mEhODbXD-0REGXvk8xtvCbfvZwC2GYqz8MZb9rBrnWo4FwQ5cJTznwpmdgNTlklTp5eaUxQszfGPC3M7yEAfdUo9aeFc=@wintercloud.de>
Content-Type: text/plain; charset="utf-8"
Hi,
I found the solution.
The solution to my problem can be found here:
https://www.centos.org/forums/viewtopic.php?t=54348
To quote the important part:
SELINUX. That is what was stopping the DHCP failover cluster from forming.
The [guide to configuring DHCP
failover](https://kb.isc.org/article/AA-00502/0/A-Basic-Guide-to-Configuring-DHCP-Failover.html)
from the ISC knowledge base, suggested using TCP ports 519 and 520 for the
failover protocol communications between the two cluster members. If you look
in my example configurations above, I have dutifully done that. I also made
sure to allow those ports through the firewalld (although I got the same result
with the firewalld halted). Yet, the cluster still would not form. "unexpected
error"
(...)
To make my cluster form, I removed the port statements from the failover
declaration sections of /etc/dhcp/dhcpd.conf, which has the effect of making
DHCPD listen on the default ports as listed in /etc/services
(...)
edited my firewalld service file I created for the dhcp failover protocol to
reflect default port 647
Best,
Nathan
??????? Original Message ???????
On 29 July 2018 12:25 PM, Nathan H?sken <nat...@wintercloud.de> wrote:
> Hi,
>
> I have stup dhcpd (isc-dhcpd-4.2.5) in a 2 peers failover setup. I start the
> service on both peers and get (example from the primary):
>
> -------------------------------------------- Output of service dhcpd status -l
> Redirecting to /bin/systemctl status -l dhcpd.service
> ? dhcpd.service - DHCPv4 Server Daemon
> Loaded: loaded (/etc/systemd/system/dhcpd.service; enabled; vendor preset:
> disabled)
> Active: active (running) since So 2018-07-29 10:18:34 UTC; 1min 36s ago
> Docs: man:dhcpd(8)
> man:dhcpd.conf(5)
> Main PID: 31729 (dhcpd)
> Status: "Dispatching packets..."
> CGroup: /system.slice/dhcpd.service
> ??31729 /usr/sbin/dhcpd -f -cf /etc/dhcp/dhcpd.conf -user dhcpd
> -group dhcpd --no-pid eth1
>
> Jul 29 10:18:34 VM-cddd5fc5-4761-492b-a814-2f450c3540cf dhcpd[31729]: For
> info, please visit https://www.isc.org/software/dhcp/
> Jul 29 10:18:34 VM-cddd5fc5-4761-492b-a814-2f450c3540cf dhcpd[31729]: Not
> searching LDAP since ldap-server, ldap-port and ldap-base-dn were not
> specified in the config file
> Jul 29 10:18:34 VM-cddd5fc5-4761-492b-a814-2f450c3540cf dhcpd[31729]: Wrote 0
> leases to leases file.
> Jul 29 10:18:34 VM-cddd5fc5-4761-492b-a814-2f450c3540cf dhcpd[31729]:
> Listening on LPF/eth1/0a:1b:c4:00:61:7c/192.168.123.0/24
> Jul 29 10:18:34 VM-cddd5fc5-4761-492b-a814-2f450c3540cf dhcpd[31729]: Sending
> on LPF/eth1/0a:1b:c4:00:61:7c/192.168.123.0/24
> Jul 29 10:18:34 VM-cddd5fc5-4761-492b-a814-2f450c3540cf dhcpd[31729]: Sending
> on Socket/fallback/fallback-net
> Jul 29 10:18:34 VM-cddd5fc5-4761-492b-a814-2f450c3540cf dhcpd[31729]:
> failover peer failover-partner-secondary: I move from recover to startup
> Jul 29 10:18:34 VM-cddd5fc5-4761-492b-a814-2f450c3540cf systemd[1]: Started
> DHCPv4 Server Daemon.
> Jul 29 10:18:49 VM-cddd5fc5-4761-492b-a814-2f450c3540cf dhcpd[31729]:
> failover peer failover-partner-secondary: I move from startup to recover
> Jul 29 10:20:04 VM-cddd5fc5-4761-492b-a814-2f450c3540cf dhcpd[31729]:
> failover peer failover-partner-secondary: unexpected error
> --------------------------------------------
>
> I get the same log on the secondary, only that it is reporting the primary is
> going to startup recovery.
>
> Here are my configs
> -------------------------------------------- /etc/dhcpd/dhcpd.conf on primary
>
> option domain-name "wntr.cloud";
> option domain-name-servers 192.168.123.1 ,192.168.123.2;
>
> default-lease-time 600;
> max-lease-time 7200;
>
> failover peer "failover-partner-secondary" {
> primary;
> address 192.168.123.1;
> port 519;
> peer address 192.168.123.2;
> peer port 520;
> mclt 3600;
> split 128;
> load balance max seconds 3;
> }
>
> subnet 192.168.123.0 netmask 255.255.255.0 {
> option broadcast-address 192.168.123.255;
> option subnet-mask 255.255.255.0;
> pool {
> failover peer "failover-partner-secondary";
> range 192.168.123.100 192.168.123.254 ;
> }
> }
> --------------------------------------------
>
> -------------------------------------------- /etc/dhcpd/dhcpd.conf on
> secondary
>
> option domain-name "wntr.cloud";
> option domain-name-servers 192.168.123.1 ,192.168.123.2;
>
> default-lease-time 600;
> max-lease-time 7200;
>
> failover peer "failover-partner-primary" {
> secondary;
> address 192.168.123.2;
> port 520;
> peer address 192.168.123.1;
> peer port 519;
> load balance max seconds 3;
> }
>
> subnet 192.168.123.0 netmask 255.255.255.0 {
> option broadcast-address 192.168.123.255;
> option subnet-mask 255.255.255.0;
> pool {
> failover peer "failover-partner-primary";
> range 192.168.123.100 192.168.123.254 ;
> }
> }
> --------------------------------------------
>
> I can communicate over ports 519/520 (udp) which I tried using netcat.
>
> Any Ideas on how to debug this?
>
> Thanks!
> Nathan
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<https://lists.isc.org/pipermail/dhcp-users/attachments/20180729/8d05e0e9/attachment-0001.html>
------------------------------
Message: 2
Date: Mon, 30 Jul 2018 13:15:19 +0200
From: Sandra Schlichting <littlesandr...@gmail.com>
To: dhcp-users@lists.isc.org
Subject: How to sync a Linux secondary DHCP server?
Message-ID:
<CAELiMBPnYX9L8U66=ppL_RypsMb=qp_0zeokwfkzypo9kky...@mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"
Dear all =)
In this article [1] they don't explain how the secondary DHCP server
gets synced and in this one [2] they sync the files with home made
scripts.
**Question**
Having a secondary DHCP server is good practice I'd say, so can it
really be correct, that DHCP on Linux doesn't have an official a way
to sync config, leases and reservations to the secondary?
[1]:
https://www.lisenet.com/2018/configure-dhcp-failover-with-dynamic-dns-on-centos-7/
[2]: https://steronius.blogspot.com/2015/10/dhcp-failover-on-rhel-7.html
Hugs,
Sandra =)
------------------------------
Subject: Digest Footer
_______________________________________________
dhcp-users mailing list
dhcp-users@lists.isc.org
https://lists.isc.org/mailman/listinfo/dhcp-users
------------------------------
End of dhcp-users Digest, Vol 117, Issue 15
*******************************************
