Linux的dhcp啟動異常怎么辦

這篇文章主要介紹“Linux的dhcp啟動異常怎么辦”，在日常操作中，相信很多人在Linux的dhcp啟動異常怎么辦問題上存在疑惑，小編查閱了各式資料，整理出簡單好用的操作方法，希望對大家解答”Linux的dhcp啟動異常怎么辦”的疑惑有所幫助！接下來，請跟著小編一起來學習吧！

    最近折騰Centos自動化安裝，需要Linux的dhcp服務，使用yum -y install dhcp安裝dhcp、dhcp-common的rpm包，啟動dhcp時異常報錯，

由于dhcp是操作系統及服務，關于dhcp啟動失敗可以查看操作系統日志/var/log/messages，使用service dhcpd start時報錯如下：

[root@localhost log]# tail -f messages

May 13 20:30:45 localhost dhcpd: Internet Systems Consortium DHCP Server 4.1.1-P1
May 13 20:30:45 localhost dhcpd: Copyright 2004-2010 Internet Systems Consortium.
May 13 20:30:45 localhost dhcpd: All rights reserved.
May 13 20:30:45 localhost dhcpd: For info, please visit https://www.isc.org/software/dhcp/
May 13 20:30:45 localhost dhcpd: Not searching LDAP since ldap-server, ldap-port and ldap-base-dn were not specified in the config file
May 13 20:30:45 localhost dhcpd: Wrote 0 leases to leases file.
May 13 20:30:45 localhost dhcpd: 
May 13 20:30:45 localhost dhcpd: No subnet declaration for eth2 (192.168.48.134).
May 13 20:30:45 localhost dhcpd: ** Ignoring requests on eth2.  If this is not what
May 13 20:30:45 localhost dhcpd:    you want, please write a subnet declaration
May 13 20:30:45 localhost dhcpd:    in your dhcpd.conf file for the network segment
May 13 20:30:45 localhost dhcpd:    to which interface eth2 is attached. **
May 13 20:30:45 localhost dhcpd: 
May 13 20:30:45 localhost dhcpd: 
May 13 20:30:45 localhost dhcpd: Not configured to listen on any interfaces!
May 13 20:30:45 localhost dhcpd: 
May 13 20:30:45 localhost dhcpd: This version of ISC DHCP is based on the release available
May 13 20:30:45 localhost dhcpd: on ftp.isc.org.  Features have been added and other changes
May 13 20:30:45 localhost dhcpd: have been made to the base software release in order to make
May 13 20:30:45 localhost dhcpd: it work better with this distribution.
May 13 20:30:45 localhost dhcpd: 
May 13 20:30:45 localhost dhcpd: Please report for this software via the CentOS Bugs Database:
May 13 20:30:45 localhost dhcpd:     http://bugs.centos.org/
May 13 20:30:45 localhost dhcpd: 
May 13 20:30:45 localhost dhcpd: exiting.

    針對dhcp啟動No subnet declaration for eth的報錯，需要排查確認信息：

1、dhcp報錯提示的ethn網卡與dhcp配置文件在同一網段確定subnet為192.168.48.0

[root@myserver tftpboot]# cat /etc/dhcpd.conf
ddns-update-style none; #設置DHCP服務器模式
ignore client-updates; #禁止客戶端更新
subnet 192.168.48.0 netmask 255.255.255.0 { #設置網段
  option routers 192.168.48.254; #設置網關
  range  192.168.48.160 192.168.48.200; #設置dhcp服務器IP地址租用的范圍
  default-lease-time 604800; #默認租約時間
  max-lease-time 605800; #最大租約時間
  next-server 192.168.48.134; #tftp服務器地址
  filename "pxelinux.0"; #tftp服務器根目錄下面的文件名
}
[root@myserver tftpboot]# 

2、使用vmware虛擬機時，需要注意dhcp配置的subnet在eth0網卡Ip所在網段，并且eth0不能是hostonly，可以是橋接模式或NAT模式，

同時需要在linux主機內ping通vmware自己的網卡Ip地址。

    然后，啟動dhcp不使用service dhcpd start而使用dhcpd -cf /etc/dhcpd.conf eth2在dhcp啟動的時候指定dhcp監聽的網卡，

dhcp啟動就能正常啟動了。

[root@myserver tftpboot]# dhcpd -cf /etc/dhcpd.conf eth2
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/
he config file
Wrote 2 leases to leases file.
Listening on LPF/eth2/00:0c:29:89:78:3d/192.168.48.0/24
Sending on   LPF/eth2/00:0c:29:89:78:3d/192.168.48.0/24
Sending on   Socket/fallback/fallback-net
[root@myserver tftpboot]# There's already a DHCP server running.
This version of ISC DHCP is based on the release available
on ftp.isc.org.  Features have been added and other changes
have been made to the base software release in order to make
it work better with this distribution.
Please report for this software via the CentOS Bugs Database:
    http://bugs.centos.org/
exiting.
[root@myserver tftpboot]# service dhcpd status
dhcpd (pid  2501) is running...
[root@myserver tftpboot]#

    如果需要開機自動啟動dhcp，這時再使用命令chkconfig dhcp on，可以將dhcpd -cf /etc/dhcpd.conf eth2添加到/etc/rc.local

到此，關于“Linux的dhcp啟動異常怎么辦”的學習就結束了，希望能夠解決大家的疑惑。理論與實踐的搭配能更好的幫助大家學習，快去試試吧！若想繼續學習更多相關知識，請繼續關注億速云網站，小編會繼續努力為大家帶來更多實用的文章！