小弟在型号为3620的路由器上设置串口S0/0时，出现以下语句
Router(config)#int s0/0
Router(config-if)#ip add 200.1.1.1 255.255.255.
% Incomplete command.
Router(config-if)#ip add 200.1.1.1 255.255.255.0
Router(config-if)#no shut
%LINK-3-UPDOWN: Interface Serial0/0, changed state to up
%LINK-3-UPDOWN: Interface Serial0/0, changed state to down
%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0, changed state to down
Router(config-if)#^Z
%SYS-5-CONFIG_I: Configured from console by console
Router#sh ip int bri
Interface
IP-AddressOK? Method Status
Protocol
Serial0/0
200.1.1.1 YES unsetup
down
Ethernet0/0
192.168.1.1 YES unsetup
up
为什么会自动的把Protocol调成down的！请会的大侠帮帮忙！
怎样阻止这情况出现或如何把他调回UP！
因为现在就连此串口都PING 不到！帮帮忙！
