I'm trying to get a DHCP server running on a Raspberry Pi 3 Model B. I've followed instructions in several guides I've found and keep seeing the same error when I try to start the server:

root@killarney:/etc/network# service isc-dhcp-server restart.
/etc/init.d/isc-dhcp-server: 23: /etc/default/isc-dhcp-server: subnet: not found
/etc/init.d/isc-dhcp-server: 24: /etc/default/isc-dhcp-server: range: not found
/etc/init.d/isc-dhcp-server: 26: /etc/default/isc-dhcp-server: Syntax error: "}" unexpected

Contents of /etc/default/isc-dhcp-server

# Defaults for isc-dhcp-server initscript
# sourced by /etc/init.d/isc-dhcp-server
# installed at /etc/default/isc-dhcp-server by the maintainer scripts

# This is a POSIX shell fragment

# Path to dhcpd's config file (default: /etc/dhcp/dhcpd.conf).

# Path to dhcpd's PID file (default: /var/run/dhcpd.pid).

# Additional options to start dhcpd with.
#       Don't use options -cf or -pf here; use DHCPD_CONF/ DHCPD_PID instead

# On what interfaces should the DHCP server (dhcpd) serve DHCP requests?
#       Separate multiple interfaces with spaces, e.g. "eth0 eth1".

subnet netmask {
  #option routers pepper.spices.org;

Line 23 is the one starting with 'subnet'. I do not understand the error message.

Other info...

root@killarney:/etc/network# cat interfaces
# interfaces(5) file used by ifup(8) and ifdown(8)

# Please note that this file is written to be used with dhcpcd
# For static IP, consult /etc/dhcpcd.conf and 'man dhcpcd.conf'

# Include files from /etc/network/interfaces.d:
source-directory /etc/network/interfaces.d

auto lo
iface lo inet loopback

#config eth0 for dhcp
iface eth0 inet static

allow-hotplug wlan0
iface wlan0 inet manual
    wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf

allow-hotplug wlan1
iface wlan1 inet manual
    wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf


root@killarney:/etc/network# ifconfig
eth0      Link encap:Ethernet  HWaddr b8:27:eb:1a:4b:e6  
          inet addr:  Bcast:  Mask:
          inet6 addr: fe80::3f6b:9d4c:b66f:161f/64 Scope:Link
          RX packets:82718 errors:0 dropped:0 overruns:0 frame:0
          TX packets:15543 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:121229265 (115.6 MiB)  TX bytes:1498876 (1.4 MiB)

lo        Link encap:Local Loopback  
          inet addr:  Mask:
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:1097 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1097 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1 
          RX bytes:110224 (107.6 KiB)  TX bytes:110224 (107.6 KiB)

wlan0     Link encap:Ethernet  HWaddr b8:27:eb:4f:1e:b3  
          inet addr:  Bcast:  Mask:
          inet6 addr: 2601:249:e00:b215:167c:a6f7:a793:93d5/64 Scope:Global
          inet6 addr: fe80::7764:92ff:8797:f8f9/64 Scope:Link
          inet6 addr: 2601:249:e00:b215::1d53/128 Scope:Global
          RX packets:32960 errors:0 dropped:3278 overruns:0 frame:0
          TX packets:18197 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:32901505 (31.3 MiB)  TX bytes:2421876 (2.3 MiB)


What have I overlooked?


PS Should be tagged dhcpd but I cannot create that tag. :(

  • You appear to be running (or attempting to run) a dhcp server and a dhcp client. Decide what you want to do.
    – Milliways
    Jan 19, 2017 at 22:41
  • I can't have both? DHCP client on wlan0 and DHCP server on eth0? The host is multi-homed.
    – HankB
    Jan 21, 2017 at 2:28

1 Answer 1


I don't think you put your subnet stuff in the /etc/default/isc-dhcp-server file. That should live in the config file /etc/dhcp/dhcpd.conf here.

  • I tried moving the information from '/etc/default/isc-dhcp-server' to '/etc/dhcp/dhcpd.conf' and it did change the error messages. No Joy. I moved on and configured the device that needed the IP address for a static IP.
    – HankB
    Jan 21, 2017 at 2:31
  • To clarify my answer, you'd leave the INTERFACES line in the default and only move the subnet stanza out into the config file. I-D-S throws another error if that INTERFACES block isn't in the default file. You have to be careful about formatting and semicolons in the config file. If its a simple setup i'd look into dnsmasq as an alternative, its a bit more at the scale Pi's get used at. Glad its sorted one way or the other though.
    – user29019
    Jan 21, 2017 at 8:51

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