H3C S5560-30F-EI 日志频繁提示DHCP信息

作为核心使用，并在核心上开启DHCP，日志如下：

%Nov 16 16:39:03:219 2019 XDYY_HX_5560_7F DHCPS/5/DHCPS_EXTEND_IP: Server IP = 192.168.2.1, DHCP client IP = 192.168.2.59, DHCP client hardware address = 7862-56db-2f16, DHCP client lease = 28800 seconds. 

%Nov 16 16:39:28:259 2019 XDYY_HX_5560_7F DHCPS/5/DHCPS_EXTEND_IP: Server IP = 192.168.2.1, DHCP client IP = 192.168.2.59, DHCP client hardware address = 7862-56db-2f16, DHCP client lease = 28800 seconds. 

%Nov 16 16:40:02:461 2019 XDYY_HX_5560_7F DHCPS/5/DHCPS_EXTEND_IP: Server IP = 192.168.2.1, DHCP client IP = 192.168.2.146, DHCP client hardware address = b052-16b9-b46f, DHCP client lease = 28800 seconds. 

%Nov 16 16:40:29:923 2019 XDYY_HX_5560_7F DHCPS/5/DHCPS_EXTEND_IP: Server IP = 192.168.2.1, DHCP client IP = 192.168.2.29, DHCP client hardware address = 5ccf-7f16-cd11, DHCP client lease = 28800 seconds. 

%Nov 16 16:40:40:123 2019 XDYY_HX_5560_7F DHCPS/5/DHCPS_EXTEND_IP: Server IP = 192.168.2.1, DHCP client IP = 192.168.2.17, DHCP client hardware address = 5ccf-7f10-8409, DHCP client lease = 28800 seconds. Release Version: H3C S5560-30F-EI-1122 

%Nov 16 16:43:36:628 2019 XDYY_HX_5560_7F DHCPS/5/DHCPS_RECLAIM_IP: Server IP = 192.168.2.1, DHCP client IP = 192.168.2.136, DHCP client hardware address = 0011-32b4-820b, DHCP client lease = 28800 seconds. 

%Nov 16 16:45:31:124 2019 XDYY_HX_5560_7F DHCPS/5/DHCPS_EXTEND_IP: Server IP = 192.168.2.1, DHCP client IP = 192.168.2.29, DHCP client hardware address = 5ccf-7f16-cd11, DHCP client lease = 28800 seconds. 

%Nov 16 16:46:16:613 2019 XDYY_HX_5560_7F DHCPS/5/DHCPS_RECLAIM_IP: Server IP = 192.168.2.1, DHCP client IP = 192.168.2.27, DHCP client hardware address = 3837-8bbb-e303, DHCP client lease = 28800 seconds.

使用过程中没有问题。想了解，该日志提示，是什么意思，起到什么作用？