DHCP服务出现unavailable

fjchenq

网络划分为几个vlan
172.27.10.0/24
172.27.20.0/24
172.27.90.0/23
172.27.100.0/24
172.27.110.0/24
DHCP 服务器放在172.27.200.7 (centos 5.9  dhcp 3.0.5)
核心交换机（h3c 7500)通过dhcp  relay 到dhcp 服务器
原先是用windows 2003充当dhcp服务器，但过半小时左右，终端就获取不到ip地址。
后来用h3c交换机直接架设dhcp server,但比较不好用，较难配置ip-mac对。
也出现 ip-in-use  free-ip加起来没有全个ip段的地址
后来决定用linux服务器
/var/log/messages出现大量如下的信息：(DHCPREQUEST for ... from  via ... lease... unavailable)
Feb 26 14:41:22 centos-dhcp1 dhcpd: DHCPREQUEST for 172.27.100.240 (172.27.200.7) from 3c:e5:a6:cc:ac:0e via 172.27.100.254: lease 172.27.100.240 unavailable.
Feb 26 14:41:22 centos-dhcp1 dhcpd: DHCPNAK on 172.27.100.240 to 3c:e5:a6:cc:ac:0e via 172.27.100.254
Feb 26 14:41:52 centos-dhcp1 dhcpd: DHCPREQUEST for 172.27.100.235 (172.27.200.7) from 3c:e5:a6:cc:ac:0e via 172.27.100.254: lease 172.27.100.235 unavailable.
Feb 26 14:41:52 centos-dhcp1 dhcpd: DHCPNAK on 172.27.100.235 to 3c:e5:a6:cc:ac:0e via 172.27.100.254
Feb 26 14:42:20 centos-dhcp1 dhcpd: DHCPREQUEST for 172.27.100.233 from 7c:11:be:a3:06:af (Tinamato-iPhone) via 172.27.100.254
Feb 26 14:42:20 centos-dhcp1 dhcpd: DHCPACK on 172.27.100.233 to 7c:11:be:a3:06:af (Tinamato-iPhone) via 172.27.100.254
Feb 26 14:42:22 centos-dhcp1 dhcpd: DHCPREQUEST for 172.27.100.233 (172.27.200.7) from 3c:e5:a6:cc:ac:0e via 172.27.100.254: lease 172.27.100.233 unavailable.
Feb 26 14:42:22 centos-dhcp1 dhcpd: DHCPNAK on 172.27.100.233 to 3c:e5:a6:cc:ac:0e via 172.27.100.254
Feb 26 14:42:41 centos-dhcp1 dhcpd: DHCPREQUEST for 172.27.90.168 from e8:8d:28:cf:d1:c1 via 172.27.91.254
Feb 26 14:42:41 centos-dhcp1 dhcpd: DHCPACK on 172.27.90.168 to e8:8d:28:cf:d1:c1 via 172.27.91.254
Feb 26 14:42:45 centos-dhcp1 dhcpd: DHCPDISCOVER from 00:23:76:b7:ce:11 (android_185887f89019f930) via 172.27.91.254
Feb 26 14:42:46 centos-dhcp1 dhcpd: DHCPOFFER on 172.27.91.192 to 00:23:76:b7:ce:11 (android_185887f89019f930) via 172.27.91.254
Feb 26 14:42:46 centos-dhcp1 dhcpd: DHCPREQUEST for 172.27.91.192 (172.27.200.7) from 00:23:76:b7:ce:11 (android_185887f89019f930) via 172.27.91.254
Feb 26 14:42:46 centos-dhcp1 dhcpd: DHCPACK on 172.27.91.192 to 00:23:76:b7:ce:11 (android_185887f89019f930) via 172.27.91.254
Feb 26 14:42:52 centos-dhcp1 dhcpd: DHCPREQUEST for 172.27.100.138 (172.27.200.7) from 3c:e5:a6:cc:ac:0e via 172.27.100.254: lease 172.27.100.138 unavailable.
Feb 26 14:42:52 centos-dhcp1 dhcpd: DHCPNAK on 172.27.100.138 to 3c:e5:a6:cc:ac:0e via 172.27.100.254
Feb 26 14:43:22 centos-dhcp1 dhcpd: DHCPREQUEST for 172.27.100.237 (172.27.200.7) from 3c:e5:a6:cc:ac:0e via 172.27.100.254: lease 172.27.100.237 unavailable.
Feb 26 14:43:22 centos-dhcp1 dhcpd: DHCPNAK on 172.27.100.237 to 3c:e5:a6:cc:ac:0e via 172.27.100.254
Feb 26 14:43:45 centos-dhcp1 dhcpd: DHCPREQUEST for 172.27.100.233 from 7c:11:be:a3:06:af (Tinamato-iPhone) via 172.27.100.254
Feb 26 14:43:45 centos-dhcp1 dhcpd: DHCPACK on 172.27.100.233 to 7c:11:be:a3:06:af (Tinamato-iPhone) via 172.27.100.254
Feb 26 14:43:52 centos-dhcp1 dhcpd: DHCPREQUEST for 172.27.100.119 (172.27.200.7) from 3c:e5:a6:cc:ac:0e via 172.27.100.254: lease 172.27.100.119 unavailable.
Feb 26 14:43:52 centos-dhcp1 dhcpd: DHCPNAK on 172.27.100.119 to 3c:e5:a6:cc:ac:0e via 172.27.100.254
Feb 26 14:44:22 centos-dhcp1 dhcpd: DHCPREQUEST for 172.27.91.19 (172.27.200.7) from 3c:e5:a6:cc:ac:0e via 172.27.91.254: lease 172.27.91.19 unavailable.
Feb 26 14:44:22 centos-dhcp1 dhcpd: DHCPNAK on 172.27.91.19 to 3c:e5:a6:cc:ac:0e via 172.27.91.254
Feb 26 14:44:52 centos-dhcp1 dhcpd: DHCPREQUEST for 172.27.100.108 (172.27.200.7) from 3c:e5:a6:cc:ac:0e via 172.27.100.254: lease 172.27.100.108 unavailable.
Feb 26 14:44:52 centos-dhcp1 dhcpd: DHCPNAK on 172.27.100.108 to 3c:e5:a6:cc:ac:0e via 172.27.100.254
Feb 26 14:45:22 centos-dhcp1 dhcpd: DHCPREQUEST for 172.27.100.107 (172.27.200.7) from 3c:e5:a6:cc:ac:0e via 172.27.100.254: lease 172.27.100.107 unavailable.
Feb 26 14:45:22 centos-dhcp1 dhcpd: DHCPNAK on 172.27.100.107 to 3c:e5:a6:cc:ac:0e via 172.27.100.254
Feb 26 14:45:33 centos-dhcp1 dhcpd: DHCPINFORM from 172.27.200.5 via eth0: unknown subnet for address 172.27.200.5
Feb 26 14:45:35 centos-dhcp1 last message repeated 3 times
Feb 26 14:45:52 centos-dhcp1 dhcpd: DHCPREQUEST for 172.27.91.17 (172.27.200.7) from 3c:e5:a6:cc:ac:0e via 172.27.91.254: lease 172.27.91.17 unavailable.
Feb 26 14:45:52 centos-dhcp1 dhcpd: DHCPNAK on 172.27.91.17 to 3c:e5:a6:cc:ac:0e via 172.27.91.254
Feb 26 14:46:22 centos-dhcp1 dhcpd: DHCPREQUEST for 172.27.90.23 (172.27.200.7) from 3c:e5:a6:cc:ac:0e via 172.27.91.254: lease 172.27.90.23 unavailable.
Feb 26 14:46:22 centos-dhcp1 dhcpd: DHCPNAK on 172.27.90.23 to 3c:e5:a6:cc:ac:0e via 172.27.91.254
Feb 26 14:46:50 centos-dhcp1 dhcpd: DHCPREQUEST for 172.27.100.213 from 84:29:99:68:36:45 (Angelamato-iPad) via 172.27.100.254
Feb 26 14:46:50 centos-dhcp1 dhcpd: DHCPACK on 172.27.100.213 to 84:29:99:68:36:45 (Angelamato-iPad) via 172.27.100.254
Feb 26 14:46:52 centos-dhcp1 dhcpd: DHCPREQUEST for 172.27.91.35 (172.27.200.7) from 3c:e5:a6:cc:ac:0e via 172.27.91.254: lease 172.27.91.35 unavailable.
Feb 26 14:46:52 centos-dhcp1 dhcpd: DHCPNAK on 172.27.91.35 to 3c:e5:a6:cc:ac:0e via 172.27.91.254
Feb 26 14:47:22 centos-dhcp1 dhcpd: DHCPREQUEST for 172.27.91.7 (172.27.200.7) from 3c:e5:a6:cc:ac:0e via 172.27.91.254: lease 172.27.91.7 unavailable.
Feb 26 14:47:22 centos-dhcp1 dhcpd: DHCPNAK on 172.27.91.7 to 3c:e5:a6:cc:ac:0e via 172.27.91.254
Feb 26 14:47:52 centos-dhcp1 dhcpd: DHCPREQUEST for 172.27.91.11 (172.27.200.7) from 3c:e5:a6:cc:ac:0e via 172.27.91.254: lease 172.27.91.11 unavailable.
Feb 26 14:47:52 centos-dhcp1 dhcpd: DHCPNAK on 172.27.91.11 to 3c:e5:a6:cc:ac:0e via 172.27.91.254
Feb 26 14:48:06 centos-dhcp1 dhcpd: DHCPREQUEST for 172.27.90.168 from e8:8d:28:cf:d1:c1 via 172.27.91.254
Feb 26 14:48:06 centos-dhcp1 dhcpd: DHCPACK on 172.27.90.168 to e8:8d:28:cf:d1:c1 via 172.27.91.254
Feb 26 14:48:22 centos-dhcp1 dhcpd: DHCPREQUEST for 172.27.91.39 (172.27.200.7) from 3c:e5:a6:cc:ac:0e via 172.27.91.254: lease 172.27.91.39 unavailable.
Feb 26 14:48:22 centos-dhcp1 dhcpd: DHCPNAK on 172.27.91.39 to 3c:e5:a6:cc:ac:0e via 172.27.91.254
Feb 26 14:48:52 centos-dhcp1 dhcpd: DHCPREQUEST for 172.27.90.20 (172.27.200.7) from 3c:e5:a6:cc:ac:0e via 172.27.91.254: lease 172.27.90.20 unavailable.
Feb 26 14:48:52 centos-dhcp1 dhcpd: DHCPNAK on 172.27.90.20 to 3c:e5:a6:cc:ac:0e via 172.27.91.254
Feb 26 14:49:04 centos-dhcp1 dhcpd: DHCPDISCOVER from 68:9c:5e:79:44:b0 (android_669c1aecef7bc157) via 172.27.100.254
Feb 26 14:49:05 centos-dhcp1 dhcpd: DHCPOFFER on 172.27.100.218 to 68:9c:5e:79:44:b0 (android_669c1aecef7bc157) via 172.27.100.254
Feb 26 14:49:05 centos-dhcp1 dhcpd: DHCPREQUEST for 172.27.100.218 (172.27.200.7) from 68:9c:5e:79:44:b0 (android_669c1aecef7bc157) via 172.27.100.254
Feb 26 14:49:05 centos-dhcp1 dhcpd: DHCPACK on 172.27.100.218 to 68:9c:5e:79:44:b0 (android_669c1aecef7bc157) via 172.27.100.254
Feb 26 14:49:22 centos-dhcp1 dhcpd: DHCPREQUEST for 172.27.100.102 (172.27.200.7) from 3c:e5:a6:cc:ac:0e via 172.27.100.254: lease 172.27.100.102 unavailable.
Feb 26 14:49:22 centos-dhcp1 dhcpd: DHCPNAK on 172.27.100.102 to 3c:e5:a6:cc:ac:0e via 172.27.100.254
Feb 26 14:49:52 centos-dhcp1 dhcpd: DHCPREQUEST for 172.27.91.3 (172.27.200.7) from 3c:e5:a6:cc:ac:0e via 172.27.91.254: lease 172.27.91.3 unavailable.

应该如何网络中的dhcp异常问题？期待回复

tooo

我看看啊