dpcp serverの冗長化
dhcp-server冗長化のためにfailover設定を有効にする
1台がprimary,もう1台がsecondary.
failover設定を有効にすると、dhcp-poolを複数台のdhcp-serverで共有する
そのために - 共通のpool定義を作る - primary,secondaryの設定をそれぞれかく
共通の設定ファイル
subnet 192.168.100.0 netmask 255.255.255.0 {
option routers gw.example.com;
option broadcast-address 192.168.100.255;
option subnet-mask 255.255.255.0;
# pool定義
pool {
failover peer "failover-partner";
range 192.168.100.100 192.168.100.200;
}
}
primary
failover peer "failover-partner" {
primary;
address 192.168.100.1;
port 519;
peer address 192.168.100.2;
peer port 520;
max-response-delay 60;
max-unacked-updates 10;
mclt 3600;
split 128;
load balance max seconds 3;
}
include "/etc/dhcp/dhcpd-common.conf";
secondary
failover peer "failover-partner" {
# secondaryとするのがポイント
secondary;
address 192.168.100.2;
port 520;
peer address 192.168.100.1;
peer port 519;
max-response-delay 60;
max-unacked-updates 10;
mclt 3600;
# secondary側ではsplitを書いてはいけない
# split 128
load balance max seconds 3;
}
include "/etc/dhcp/dhcpd-common.conf";
環境
- debian10
- isc-dhcp-server
test
vmを立ち上げ、ipaddressが取得できるか確認、取得できない。
vmでMacAddressを確認
$ ip a
...
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
link/ether 08:00:27:ec:35:e7 brd ff:ff:ff:ff:ff:ff
08:00:27:ec:35:e7をdhcp-serverのログから探すと、
$ sudo journalctl -xe ... Dec 11 15:39:45 dhcp dhcpd[2543]: DHCPDISCOVER from 08:00:27:ec:35:e7 via eth1: not responding (recover wait) ...
ググったところ時刻があっていない場合に出るログ。
ntp-server停めてたわ。。。こちらも冗長構成にしないとな。
Dec 11 16:29:25 dhcp dhcpd[394]: DHCPDISCOVER from 08:00:27:ec:35:e7 via eth1 Dec 11 16:29:26 dhcp dhcpd[394]: DHCPOFFER on 192.168.100.151 to 08:00:27:ec:35:e7 (debian10.localdomain) via eth1 Dec 11 16:29:26 dhcp dhcpd[394]: uid lease 192.168.100.151 for client 08:00:27:ec:35:e7 is duplicate on 192.168.100.0/24 Dec 11 16:29:26 dhcp dhcpd[394]: DHCPREQUEST for 192.168.100.101 (192.168.100.21) from 08:00:27:ec:35:e7 via eth1: lease owned by peer Dec 11 16:29:43 dhcp dhcpd[394]: DHCPDISCOVER from 08:00:27:ec:35:e7 via eth1 Dec 11 16:29:44 dhcp dhcpd[394]: uid lease 192.168.100.151 for client 08:00:27:ec:35:e7 is duplicate on 192.168.100.0/24 Dec 11 16:29:44 dhcp dhcpd[394]: DHCPREQUEST for 192.168.100.102 (192.168.100.21) from 08:00:27:ec:35:e7 via eth1: lease owned by peer Dec 11 16:29:44 dhcp dhcpd[394]: DHCPOFFER on 192.168.100.101 to 08:00:27:ec:35:e7 (debian10.localdomain) via eth1
