HDLC配置<高级数据链路控制>：
配置路由器使用广域网封装协议：HDLC
[RTA]int e0/0
[RTA-Ethernet0/0]ip add 192.168.1.1 24
[RTA]int s0/0
[RTA-s0/0]ip add 10.1.1.1 24
[RTB]int e0/0
[RTB-Ethernet0/0]ip add 192.168.2.1 24
[RTB]int s0/0
[RTB-s0/0]ip add 10.1.1.2 24
PCA:192.168.1.2 255.255.255.0 GT:192.168.1.1
PCB:192.168.2.2 255.255.255.0 GT:192.168.2.1
[RTA]ip route-static 192.168.2.0 255.255.255.0 10.1.1.2
[RTB]ip route-static 192.168.1.0 255.255.255.0 10.1.1.1
此时PCA和PCB可以互访：
C:\Documents and Settings\xiaofei>ping 192.168.2.2
Pinging 192.168.2.2 with 32 bytes of data:
Reply from 192.168.2.2: bytes=32 time=2ms TTL=254
Reply from 192.168.2.2: bytes=32 time<1ms TTL=254
Ping statistics for 192.168.2.2:
Packets: Sent = 2, Received = 2, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 2ms, Average = 1ms
Control-C
在RTA S0/0接口上启用HDLC协议：
RTA]int s0/0
[RTA-s0/0]link-protocol hdlc
[RTA-s0/0]buadrate 9600
此时PCA和PCB已经无法互访:
C:\Documents and Settings\xiaofei>ping 192.168.2.2
Pinging 192.168.2.2 with 32 bytes of data:
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Ping statistics for 192.168.2.2:
Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),
已经H3C 路由器默认封装是PPP协议，所以需要将RTB的S0/0也配置为HDLC才行：
[RTB]int s0/0
[RTB-s0/0]link-protocol hdlc
此时接口都启用HDLC协议，PCA和PCB又可以正常互访了：
[RTA] disp int s0/0
Serial0/0/0 current state: UP
Line protocol current state: UP
Description: Serial0/0/0 Interface
The Maximum Transmit Unit is 1500, Hold timer is 10(sec)
Internet Address is 10.1.1.1/24 Primary
Link layer protocol is HDLC
Output queue : (Urgent queuing : Size/Length/Discards) 0/50/0
Output queue : (Protocol queuing : Size/Length/Discards) 0/500/0
Output queue : (FIFO queuing : Size/Length/Discards) 0/75/0
Interface is V35
525 packets input, 7860 bytes
508 packets output, 7584 bytes
C:\Documents and Settings\xiaofei>ping 192.168.2.2
Pinging 192.168.2.2 with 32 bytes of data:
Reply from 192.168.2.2: bytes=32 time=15ms TTL=254
Reply from 192.168.2.2: bytes=32 time=1ms TTL=254
Reply from 192.168.2.2: bytes=32 time=1ms TTL=254
Reply from 192.168.2.2: bytes=32 time<1ms TTL=254
Ping statistics for 192.168.2.2:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 15ms, Average = 4ms