今天，我将dhcp和dns服务器从旧的centos5迁移到运行Scientific Linux 6.8的新机器上。 named服务器似乎工作正常，但是DHCP服务器有一些问题。 客户端没有获得IP地址。
现在我已经做了必要的研究，看看发生了什么事情，是什么原因造成的。
现在的情况
在Scientific Linux 6.8上，安装了以下软件包：
/var/log/messages显示以下输出：
Sep 29 23:52:14 kowalski dhcpd: DHCPDISCOVER from 00:15:17:17:5b:b0 via eth0 Sep 29 23:52:14 kowalski dhcpd: DHCPOFFER on 111.122.133.144 to 00:15:17:17:5b:b0 via eth0
使用tcpdump：
domain.tld.bootps > somdomain.tld.bootpc: [udp sum ok] BOOTP/DHCP, Reply, length 311, xid 0xaeee0934, secs 19, Flags [none] (0x0000) Your-IP somdomain.tld. Server-IP somdomain.tld. Client-Ethernet-Address 00:12:xx:xx:5b:b0 (oui Unknown) file "pxelinux.0" Vendor-rfc1048 Extensions Magic Cookie 0x63825363 DHCP-Message Option 53, length 1: Offer Server-ID Option 54, length 4: domain.tld Lease-Time Option 51, length 4: 7200 Subnet-Mask Option 1, length 4: 255.255.0.0 Domain-Name Option 15, length 12: "somdomain.tld." Domain-Name-Server Option 6, length 4: ns1.external.nl Hostname Option 12, length 21: "somdomain.tld.^@" Default-Gateway Option 3, length 4: router.somdomain.tld. END Option 255, length 0 23:53:01.007595 IP (tos 0x0, ttl 128, id 0, offset 0, flags [none], proto UDP (17), length 364) 0.0.0.0.bootpc > 255.255.255.255.bootps: [udp sum ok] BOOTP/DHCP, Request from 00:15:17:17:5b:b0 (oui Unknown), length 336, xid 0xaeee0934, secs 29, Flags [none] (0x0000) Client-Ethernet-Address 00:15:17:17:5b:b0 (oui Unknown) Vendor-rfc1048 Extensions Magic Cookie 0x63825363 DHCP-Message Option 53, length 1: Discover Requested-IP Option 50, length 4: somdomain.tld. Hostname Option 12, length 20: "somdomain.tld." Parameter-Request Option 55, length 17: Subnet-Mask, BR, Time-Zone, Classless-Static-Route Domain-Name, Domain-Name-Server, Hostname, YD YS, NTP, MTU, Option 119 Default-Gateway, Classless-Static-Route, Classless-Static-Route-Microsoft, Static-Route NTP Vendor-Class Option 60, length 43: "anaconda-Linux 2.6.32-573.el6.x86_64 x86_64" END Option 255, length 0 23:53:01.008693 IP (tos 0x10, ttl 128, id 0, offset 0, flags [none], proto UDP (17), length 339) somdomain.tld..bootps > host.within.domain.tld.bootpc: [udp sum ok] BOOTP/DHCP, Reply, length 311, xid 0xaeee0934, secs 29, Flags [none] (0x0000) Your-IP host.within.domain.tld.bootpc
我的假设是，服务器连接在交换机端口，阻止某些客户端发送DHCPREQUEST 。 但是，那么如何允许客户端发送一个DHCPDISCOVERY并且服务器回复一个DHCPOFFER
我做了很多debugging，但无法find解决scheme。 客户端在dhcpd.conf有一个fixed-address 。 例如：
host supernova {hardware ethernet A0:D1:CC:0A:FF:D1; fixed-address 111.122.133.145; }
任何正确的方向帮助或build议是最感激！