我一直在关注这Ubuntu 上的教程教我如何在我的机器上设置 DHCP 服务器，但我就是无法让它工作。当我运行
sudo systemctl restart isc-dhcp-server.service
sudo systemctl status isc-dhcp-server.service
它给了我错误状态failed，以及以下输出/var/log/syslog：
systemd[1303]: gnome-launched-code.desktop-6211.scope: Succeeded.
Apr 20 18:51:20 dragonfly systemd[1]: Started ISC DHCP IPv4 server.
Apr 20 18:51:20 dragonfly dhcpd[6757]: Internet Systems Consortium DHCP Server 4.4.1
Apr 20 18:51:20 dragonfly sh[6757]: Internet Systems Consortium DHCP Server 4.4.1
Apr 20 18:51:20 dragonfly sh[6757]: Copyright 2004-2018 Internet Systems Consortium.
Apr 20 18:51:20 dragonfly sh[6757]: All rights reserved.
Apr 20 18:51:20 dragonfly sh[6757]: For info, please visit https://www.isc.org/software/dhcp/
Apr 20 18:51:20 dragonfly dhcpd[6757]: Copyright 2004-2018 Internet Systems Consortium.
Apr 20 18:51:20 dragonfly dhcpd[6757]: All rights reserved.
Apr 20 18:51:20 dragonfly dhcpd[6757]: For info, please visit https://www.isc.org/software/dhcp/
Apr 20 18:51:20 dragonfly dhcpd[6757]: Config file: /etc/dhcp/dhcpd.conf
Apr 20 18:51:20 dragonfly sh[6757]: Config file: /etc/dhcp/dhcpd.conf
Apr 20 18:51:20 dragonfly sh[6757]: Database file: /var/lib/dhcp/dhcpd.leases
Apr 20 18:51:20 dragonfly sh[6757]: PID file: /run/dhcp-server/dhcpd.pid
Apr 20 18:51:20 dragonfly dhcpd[6757]: Database file: /var/lib/dhcp/dhcpd.leases
Apr 20 18:51:20 dragonfly sh[6757]: Wrote 0 leases to leases file.
Apr 20 18:51:20 dragonfly dhcpd[6757]: PID file: /run/dhcp-server/dhcpd.pid
Apr 20 18:51:20 dragonfly dhcpd[6757]: Wrote 0 leases to leases file.
Apr 20 18:51:20 dragonfly dhcpd[6757]:
Apr 20 18:51:20 dragonfly sh[6757]: No subnet declaration for eth4 (no IPv4 addresses).
Apr 20 18:51:20 dragonfly sh[6757]: ** Ignoring requests on eth4. If this is not what
Apr 20 18:51:20 dragonfly sh[6757]: you want, please write a subnet declaration
Apr 20 18:51:20 dragonfly sh[6757]: in your dhcpd.conf file for the network segment
Apr 20 18:51:20 dragonfly sh[6757]: to which interface eth4 is attached. **
Apr 20 18:51:20 dragonfly sh[6757]: Not configured to listen on any interfaces!
Apr 20 18:51:20 dragonfly sh[6757]: If you think you have received this message due to a bug rather
Apr 20 18:51:20 dragonfly sh[6757]: than a configuration issue please read the section on submitting
Apr 20 18:51:20 dragonfly sh[6757]: bugs on either our web page at www.isc.org or in the README file
Apr 20 18:51:20 dragonfly sh[6757]: before submitting a bug. These pages explain the proper
Apr 20 18:51:20 dragonfly sh[6757]: process and the information we find helpful for debugging.
Apr 20 18:51:20 dragonfly sh[6757]: exiting.
Apr 20 18:51:20 dragonfly dhcpd[6757]: No subnet declaration for eth4 (no IPv4 addresses).
Apr 20 18:51:20 dragonfly dhcpd[6757]: ** Ignoring requests on eth4. If this is not what
Apr 20 18:51:20 dragonfly dhcpd[6757]: you want, please write a subnet declaration
Apr 20 18:51:20 dragonfly dhcpd[6757]: in your dhcpd.conf file for the network segment
Apr 20 18:51:20 dragonfly dhcpd[6757]: to which interface eth4 is attached. **
Apr 20 18:51:20 dragonfly dhcpd[6757]:
Apr 20 18:51:20 dragonfly dhcpd[6757]:
Apr 20 18:51:20 dragonfly dhcpd[6757]: Not configured to listen on any interfaces!
Apr 20 18:51:20 dragonfly dhcpd[6757]:
Apr 20 18:51:20 dragonfly dhcpd[6757]: If you think you have received this message due to a bug rather
Apr 20 18:51:20 dragonfly dhcpd[6757]: than a configuration issue please read the section on submitting
Apr 20 18:51:20 dragonfly dhcpd[6757]: bugs on either our web page at www.isc.org or in the README file
Apr 20 18:51:20 dragonfly dhcpd[6757]: before submitting a bug. These pages explain the proper
Apr 20 18:51:20 dragonfly dhcpd[6757]: process and the information we find helpful for debugging.
Apr 20 18:51:20 dragonfly dhcpd[6757]:
Apr 20 18:51:20 dragonfly dhcpd[6757]: exiting.
Apr 20 18:51:20 dragonfly systemd[1]: isc-dhcp-server.service: Main process exited, code=exited, status=1/FAILURE
Apr 20 18:51:20 dragonfly systemd[1]: isc-dhcp-server.service: Failed with result 'exit-code'.
Apr 20 18:52:39 dragonfly PackageKit: daemon quit
Apr 20 18:52:39 dragonfly systemd[1]: packagekit.service: Succeeded.
我猜测错误代码的相关部分是这样的：
No subnet declaration for eth4 (no IPv4 addresses).
Ignoring requests on eth4. If this is not what
you want, please write a subnet declaration
in your dhcpd.conf file for the network segment
to which interface eth4 is attached.
有人知道该怎么处理吗？我还发现这相关问题，但它已经很老了，我仍然感到困惑。
编辑：
/etc/dhcp/dhcpd.conf
default-lease-time 600;
max-lease-time 7200;
subnet 192.168.1.0 netmask 255.255.255.0 {
range 192.168.1.150 192.168.1.200;
option routers 192.168.1.254;
option domain-name-servers 192.168.1.1, 192.168.1.2;
option domain-name "mydomain.example";
}
/etc/default/isc-dhcp-server
INTERFACESv4="eth4"
输出ip addr：
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: enp4s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether f0:2f:74:dd:bb:18 brd ff:ff:ff:ff:ff:ff
inet 192.168.0.240/24 brd 192.168.0.255 scope global dynamic noprefixroute enp4s0
valid_lft 4978sec preferred_lft 4978sec
inet6 fe80::8452:bb97:94cd:6ea6/64 scope link noprefixroute
valid_lft forever preferred_lft forever
3: wlo1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
link/ether 7c:50:79:76:23:f2 brd ff:ff:ff:ff:ff:ff
altname wlp0s20f3
答案1
基于@Doug Smythies评论我让它工作了。
首先，我将/etc/default/isc-dhcp-server其改为INTERFACESv4="enp4s0"，因为这是我的有线接口，我想将其用于 DHCP。
当我运行 时ip addr，它告诉我接口enp4s0在 inet 上192.168.0.240/24。但是，在我的 中，/etc/dhcp/dhcpd.conf我将子网定义为subnet 192.168.1.0 netmask 255.255.255.0。请注意此处子网的区别，192.168.0.x和 部分192.168.1.x。要使 DHCP 服务器正常工作，这些必须匹配。所以我不得不将我的接口移动到192.168.1.x。为此，请按照以下步骤操作：
- 转到网络设置。
- 删除当前的有线设置。
- 使用图标创建一个新的
+。 - 转到
IPv4设置，更改IPv4 Method为手动，并设置Addresses字段以匹配您的dhcpd.conf配置。 有线连接 IPv4 配置 - 单击添加并保存更改。
- 当您重新打开设置时，您应该会看到刚刚设置的正确的 IPv4 地址。有线连接 IPv4 配置检查
或者，我也可以通过/etc/dhcp/dhcpd.conf将所有设置更改为 192.168.0.x 等效设置来重写我的设置以匹配子网，并且保持我的接口设置不变。
所以，现在我的正确设置是：
网络设置：我的正确设置
ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: enp4s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
link/ether 04:42:1a:2c:9e:a1 brd ff:ff:ff:ff:ff:ff
altname enp0s31f6
inet 192.168.1.0/24 brd 192.168.1.255 scope global noprefixroute enp4s0
valid_lft forever preferred_lft forever
inet6 fe80::8a50:e8aa:63c1:f6fa/64 scope link noprefixroute
valid_lft forever preferred_lft forever
3: wlo1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
link/ether 20:1e:88:2e:cc:f0 brd ff:ff:ff:ff:ff:ff
altname wlp0s20f3
inet 192.168.50.169/24 brd 192.168.50.255 scope global dynamic noprefixroute wlo1
valid_lft 15594sec preferred_lft 15594sec
inet6 fe80::45f1:e127:53a0:e49c/64 scope link noprefixroute
valid_lft forever preferred_lft forever
/etc/dhcp/dhcpd.conf
default-lease-time 600;
max-lease-time 7200;
authoritative;
subnet 192.168.1.0 netmask 255.255.255.0 {
range 192.168.1.100 192.168.1.200;
option routers 192.168.1.254;
option domain-name-servers 192.168.1.1, 192.168.1.2;
}
/etc/default/isc-dhcp-server
INTERFACESv4="enp4s0"
答案2
帮自己一个忙，使用 systemd-networkd 来设置 DHCP 服务器。
示例配置文件：/etc/systemd/network/eth0.network
[Match]
Name=eth0
[Link]
RequiredForOnline=no
[Network]
DHCPServer=yes
Address=192.168.1.1/24
ConfigureWithoutCarrier=yes
[DHCPServer]
PoolOffset=100
PoolSize=100
可以找到更多选项man systemd.network，甚至 NAT 伪装、端口转发和所有其他好的东西。
通过 启用sudo systemctl enable systemd-networkd和启动sudo systemctl restart systemd-networkd。用于监控的 CLI 工具networkctl。