某局点WX3510H AP上线异常、拿不到地址

AC——思科核心——S5130——AP

集中转发、AP二层注册、网关在思科核心、AP管理的DHCP地址池在AC。

现场反馈新增AP管理地址池70、71、72，相关AP上线异常，电脑接到5130上发现无法获取地址，手动写地址后可正常ping通AC、网关。

在AC上开启debug发现地址池70、71、72分地址有异常，只有请求报文且显示无可用IP：

*Oct 28 09:58:26:530 2021 AC_WX3510H DHCPS/7/EVENT: Receive a DHCPDISCOVER message from Vlan-interface70.

*Oct 28 09:58:26:530 2021 AC_WX3510H DHCPS/7/ERROR: No free IP in the network 192.168.70.0.

*Oct 28 09:58:26:531 2021 AC_WX3510H DHCPS/7/EVENT: Failed to allocate a lease to client.

*Oct 28 09:58:27:315 2021 AC_WX3510H DHCPS/7/PACKET:

From 0.0.0.0 port 68, interface Vlan-interface71

    Message type: REQUEST (1)

    Hardware type: 1, Hardware address length: 6

    Hops: 0, Transaction ID: 4094810419

    Seconds: 42, Broadcast flag: 0

    Client IP address: 0.0.0.0   Your IP address: 0.0.0.0

    Server IP address: 0.0.0.0   Relay agent IP address: 0.0.0.0

    Client hardware address: b845-f40f-97c0

    Server host name: not configured

    Boot file name: not configured

DHCP message type: DHCPDISCOVER (1)

命令行查看地址池display  DHCP server free-ip未发现地址池70、71、72有可用IP，display  DHCP server ip-in-use查看该地址池地址没有被使用，display  DHCP server expired无超期地址，display  DHCP server conflict无冲突地址。

dhcp server forbidden-ip 192.168.70.1 192.168.70.220

dhcp server forbidden-ip 192.168.70.251 192.168.70.255

dhcp server forbidden-ip 192.168.71.1 192.168.71.220

dhcp server forbidden-ip 192.168.71.251 192.168.71.255

dhcp server forbidden-ip 192.168.72.1 192.168.72.220

dhcp server forbidden-ip 192.168.72.251 192.168.72.255//虽然有禁用IP，但还是有一定数量IP可以分的。

#

dhcp server ip-pool 70

gateway-list 192.168.70.254

network 192.168.70.0 mask 255.255.255.0

#

dhcp server ip-pool 71

gateway-list 192.168.71.254

network 192.168.71.0 mask 255.255.255.0

#

dhcp server ip-pool 72

gateway-list 192.168.72.254

network 192.168.72.0 mask 255.255.255.0

#

#

interface Vlan-interface70

description to_4F_70

ip address 192.168.70.250 255.255.255.0

#

interface Vlan-interface71

description to_4F_71

ip address 192.168.71.250 255.255.255.0

#

interface Vlan-interface72

description to_4F_72

ip address 192.168.72.250 255.255.255.0

#

现场将DHCP地址池全部移到思科核心后，地址分发正常，ap正常上线。

由于现场配置的dhcp server forbidden-ip配置较多，仔细查看配置发现dhcp server forbidden-ip 192.168.50.251 192.168.91.255这个将地址池70、71、72的地址覆盖，所以这些地址池会显示无可用地址。

优化上诉配置后，AP正常拿到地址上线。