从DLCI 102到DLCI 301而不是201的ping是怎么回事？

Question

我刚刚配置了一个点到点帧中继的场景。如图所示，我映射DLCI如下所示：

10:102  20:201
10:103  30:301

但是，我无法弄清楚我从序列化3/0.102到序列化3/0.301的ping是如何到达序列化3/0.201的，因为映射是从102到201吗？

来自3/0.102系列的Ping：

R1#ping 192.168.2.2 source serial 3/0.102
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.2.2, timeout is 2 seconds:
Packet sent with a source address of 192.168.1.1
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 104/172/228 ms

路由器1的路由器配置：

interface FastEthernet0/0
 ip address 10.1.1.1 255.255.255.0
 duplex half
!
interface Serial3/0
 no ip address
 encapsulation frame-relay
 serial restart-delay 0
!
interface Serial3/0.102 point-to-point
 ip address 192.168.1.1 255.255.255.0
 snmp trap link-status
 frame-relay interface-dlci 102
!
interface Serial3/0.103 point-to-point
 ip address 192.168.2.1 255.255.255.0
 snmp trap link-status
 frame-relay interface-dlci 103
!
router eigrp 1
 network 10.0.0.0
 network 192.168.1.0
 network 192.168.2.0
 auto-summary

路由器2的路由器配置：

interface FastEthernet0/0
 ip address 10.2.2.1 255.255.255.0
 duplex half 
!
interface Serial3/0
 no ip address
 encapsulation frame-relay
 serial restart-delay 0
!
interface Serial3/0.201 point-to-point
 ip address 192.168.1.2 255.255.255.0
 snmp trap link-status
 frame-relay interface-dlci 201
!
router eigrp 1
 network 10.0.0.0
 network 192.168.1.0
 no auto-summary

路由器3的路由器配置：

interface FastEthernet0/0
 ip address 10.3.3.1 255.255.255.0
 duplex half
!
interface Serial3/0.301 point-to-point
 ip address 192.168.2.2 255.255.255.0
 snmp trap link-status
 frame-relay interface-dlci 301
!
router eigrp 1
 network 10.0.0.0
 network 192.168.2.0
 no auto-summary
!
interface Serial3/0
 no ip address
 encapsulation frame-relay
 serial restart-delay 0

设想情况：

Answer 1

为什么ping从R2 S3/0.102到R1 S3/0.201？ping的源只是源；它不告诉ping该往哪条路走，也不告诉流量从那个接口上怎么走。

您从R1中获取哪个接口并不重要，因为R1路由表将指示它正确的接口以到达IP地址。将ping从接口获取到R2并不重要，因为R1知道它必须将接口输出到R3。