HDLC封装问题

2x cisco 2800 routers,R1 and R2, connected together with DCE cable on serial link, both on serial3/0...
s3/0 on R1 has ip of 172.16.0.9 255.255.255.252, s3/0 on R2 has ip of 172.16.0.10 255.255.255.252

encapsulation frame-relay command typed on both routers.

as well as these:
on R1
interface Serial3/0
bandwidth 64
ip address 172.16.0.9 255.255.255.252
encapsulation frame-relay
frame-relay map ip 172.16.0.10 102 broadcast
frame-relay lmi-type ansi
clock rate 4000000
no shutdown

on R2

interface Serial3/0
bandwidth 64
ip address 172.16.0.10 255.255.255.252
encapsulation frame-relay
frame-relay map ip 172.16.0.9 201 broadcast
frame-relay lmi-type ansi
no shutdown


问题：

 

有两个接口不能互相PING通, 但是如果我将封包改为HDLC(默认) 的话这两个interface又能正常的工作，这个是什么问题，怎么解决？
i typed show interface s3/0 on both routers, and it shows interface is up but line protocol is down(disabled)

 

 

捷盈讲师及学员解答：