帧中继有路由但是ping不通远端地址

lostlsend

三台路由器 hub-spoke拓扑 R1Hub R2&R3 Spoke 分别loopback 1.1.1.1 2.2.2.2 和3.3.3.3




Q1: 为什么R2有R3的路由信息 但是ping不通R3
R1能分别ping通R2和R3的loopback
我拿wireshark抓包R2的S2/0端口发现根本没有发送任何ICMP报文 为什么？


R2 route table:

      1.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
R        1.1.1.0/24 [120/1] via 202.101.100.1, 00:00:10, Serial2/0
O        1.1.1.1/32 [110/65] via 202.101.100.1, 00:16:43, Serial2/0
      2.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C        2.2.2.0/24 is directly connected, Loopback0
L        2.2.2.2/32 is directly connected, Loopback0
      3.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
R        3.3.3.0/24 [120/2] via 202.101.100.3, 00:00:10, Serial2/0
O        3.3.3.3/32 [110/65] via 202.101.100.3, 00:16:33, Serial2/0
      202.101.100.0/24 is variably subnetted, 2 subnets, 2 masks
C        202.101.100.0/24 is directly connected, Serial2/0
L        202.101.100.2/32 is directly connected, Serial2/0


Q2: 为什么R2学习到的RIP和OSPF下一跳地址是R3的而不是R1的?
因为在我重启前RIP的下一跳地址是指向R1而OSPF是直接指向R3

配置如下:
R1:

interface Loopback0
ip address 1.1.1.1 255.255.255.0
!
!
interface Serial2/0
ip address 202.101.100.1 255.255.255.0
encapsulation frame-relay
ip ospf priority 255
serial restart-delay 0
frame-relay map ip 202.101.100.2 102
frame-relay map ip 202.101.100.3 103
!
router ospf 1
network 1.1.1.1 0.0.0.0 area 0
network 202.101.100.1 0.0.0.0 area 0
neighbor 202.101.100.3
neighbor 202.101.100.2
!
router rip
version 2
network 1.0.0.0
network 202.101.100.0
neighbor 202.101.100.2
neighbor 202.101.100.3
no auto-summary


R2:


interface Loopback0
ip address 2.2.2.2 255.255.255.0

!
interface Serial2/0
ip address 202.101.100.2 255.255.255.0
encapsulation frame-relay
serial restart-delay 0
frame-relay map ip 202.101.100.1 201
!

router ospf 1
network 2.2.2.2 0.0.0.0 area 0
network 202.101.100.2 0.0.0.0 area 0
neighbor 202.101.100.1
!
router rip
version 2
network 2.0.0.0
network 202.101.100.0
neighbor 202.101.100.1
no auto-summary



R3:

interface Loopback0
ip address 3.3.3.3 255.255.255.0
!

interface Serial2/0
ip address 202.101.100.3 255.255.255.0
encapsulation frame-relay
serial restart-delay 0
frame-relay map ip 202.101.100.1 301
!

router ospf 1
network 3.3.3.3 0.0.0.0 area 0
network 202.101.100.3 0.0.0.0 area 0
neighbor 202.101.100.1
!
router rip
version 2
network 3.0.0.0
network 202.101.100.0
neighbor 202.101.100.1
no auto-summary


FRswitch:

interface Serial2/1
no ip address
encapsulation frame-relay
serial restart-delay 0
frame-relay intf-type dce
frame-relay route 102 interface Serial2/2 201
frame-relay route 103 interface Serial2/3 301
!
interface Serial2/2
no ip address
encapsulation frame-relay
serial restart-delay 0
frame-relay intf-type dce
frame-relay route 201 interface Serial2/1 102
!
interface Serial2/3
no ip address
encapsulation frame-relay
serial restart-delay 0
frame-relay intf-type dce
frame-relay route 301 interface Serial2/1 103




所有路由器运行的是i86bi-linux-l3-adventerprisek9-ms.155-2.T.bin 在gns3环境中

lostlsend

自己把问题给解决了 原来是二层不知道对端的路径 又没有ARP的支持 不能自己发现 所以没有发送icmp包 给R2和R3分别加了一条二层的指向R1的dlci号 但是ip地址指向远端的node 就能ping通了 同理 如果要ping自己也得静态映射一条dlci号R2:

R3: