今天在调试机器的WIFI热点，好不容易把dhcp编译打包进去，服务启动出现报错No subnet declaration for wlan0，详细信息如下：
Internet Systems Consortium DHCP Server 4.1.1-P1 Copyright 2004-2010 Internet Systems Consortium. All rights reserved. For info, please visit https://www.isc.org/software/dhcp/ Wrote 0 leases to leases file. No subnet declaration for wlan0 (192.168.1.1 ). ** Ignoring requests on wlan0. If this is not what you want, please write a subnet declaration in your dhcpd.conf file for the network segment to which interface wlan0 is attached. ** Not configured to listen on any interfaces! If you did not get this software from ftp.isc.org , please get the latest from ftp.isc.org and install that before requesting help. If you did get this software from ftp.isc.org and have not yet read the README, please read it before requesting help. If you intend to request help from the dhcp-server@isc.org mailing list, please read the section on the README about submitting bug reports and requests for help. Please do not under any circumstances send requests for help directly to the authors of this software - please send them to the appropriate mailing list as described in the README file. exiting.
经过排查分析，确认是dhcpd.conf中配置的网络与给wlan0的网络配置存在冲突，不在同一个网段内：
/etc/dhcpd.conf配置网段在10.11.0.0
但是wlan0的ip地址却配置在192.168.1.1
insmod /system/vendor/modules/8188eu.ko #insmod /lib/8723bu.ko sleep 2 ifconfig wlan0 up ifconfig wlan0 192.168.1.1 netmast 255.255.255.0 sleep 1 hostapd /etc/hostapd.conf -B touch /var/lib/dhcp/dhcpd.leases dhcpd
# # Sample configuration file for ISC dhcpd for Debian # # $Id: dhcpd.conf,v 1.1.1.1 2002/05/21 00:07:44 peloy Exp $ # # The ddns-updates-style parameter controls whether or not the server will # attempt to do a DNS update when a lease is confirmed. We default to the # behavior of the version 2 packages ('none', since DHCP v2 didn't # have support for DDNS.) ddns-update-style none; # option definitions common to all supported networks... option domain-name "example.org"; option domain-name-servers ns1.example.org, ns2.example.org; default-lease-time 600; max-lease-time 7200; # If this DHCP server is the official DHCP server for the local # network, the authoritative directive should be uncommented. #authoritative; # Use this to send dhcp log messages to a different log file (you also # have to hack syslog.conf to complete the redirection). log-facility local7; # No service will be given on this subnet, but declaring it helps the # DHCP server to understand the network topology. subnet 10.11.0.0 netmask 255.255.255.0 { range 10.11.0.30 10.11.0.254; } # This is a very basic subnet declaration. #subnet 10.254.239.0 netmask 255.255.255.224 { # range 10.254.239.10 10.254.239.20; # option routers rtr-239-0-1.example.org, rtr-239-0-2.example.org; #}
只要将dhcpd.conf中的网络配置成和wlan0的启动设置一致即可解决。
subnet 192.168.1.0 netmask 255.255.255.0 { range 192.168.1.16 192.168.1.128; }