实验15配置HDLC

实验任务一：实现PCA与PCB的互通

1. 建立物理连接
   

2. 配置HDLC连接协议
   [RTA-Serial1/0]link-protocol hdlc //两个端口是HDLC或PPP接口，不对应协议接口是DOWN
   [RTA-Serial1/0]display interface Serial 1/0
   Serial1/0
   Current state: UP
   Line
   Output queue - Urgent queuing: Size/Length/Discards protocol state: UP
   Description: Serial1/0 Interface
   Band 64 kbps
   Maximum transmission unit: 1500
   Hold timer: 10 seconds, retry times: 5
   Internet address: 10.1.1.1/30 (primary)
   Link layer protocol: HDLC
   0/100/0
   Output queue - Protocol queuing: Size/Length/Discards 0/500/0
   Output queue - FIFO queuing: Size/Length/Discards 0/75/0
   Last link flapping: 0 hours 0 minutes 26 seconds
   Last clearing of counters: Never

3. RTA和RTB设置静态路由，实现PCA和PCB的互通。
   注意：
   通信两端的keepalive时间值不一样，可能导致HDLC协议状态频繁up/down,而无法正常工作。