cisco 2620路由器是怎么查看当前DHCP的配置情况的？比如我要查看当前的网段，租约期什么的。

这样查看！
sh ip dhcp ?
问号后面有一些命令选项和差数，你可以具体去查看一下！
r1#sh ip dhcp ?
binding DHCP address bindings
conflict DHCP address conflicts
database DHCP database agents
import Show Imported Parameters
pool DHCP pools information
relay Miscellaneous DHCP relay information
server Miscellaneous DHCP server information

Router#sh ip dhcp ?
binding DHCP address bindings
conflict DHCP address conflicts
database DHCP database agents
import Show Imported Parameters
pool DHCP pools information
relay Miscellaneous DHCP relay information
server Miscellaneous DHCP server information