我刚刚配置了一个点对点帧中继的场景。如图，我映射了DLCI如下图：

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

但我无法弄清楚我的 ping 从 serial3/0.102 到达 serial3/0.301 时如何到达 serial3/0.201 因为映射是从 102 到 201？

从串行 3/0.102 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：