是否可以 ping 同一个 LAN 中但在不同网络上的 PC？我已经在所有路由器上完成了 RIP 版本 2。他们都可以互相ping通。但是，PC 不能。例如，当我尝试从 FA1 ping FAS1 时，此消息显示“主机 (255.255.255.254) 无法访问”，我不确定我哪里出错了，或者还有什么需要实施。任何帮助，将不胜感激。这是我的拓扑：

默认网关：

Default_Gateway#show running-config
Building configuration...

Current configuration : 1130 bytes

version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption

hostname Default_Gateway

boot-start-marker
boot-end-marker

no aaa new-model
memory-size iomem 5
no ip icmp rate-limit unreachable
ip cef

no ip domain lookup

multilink bundle-name authenticated

archive
 log config
  hidekeys

ip tcp synwait-time 5

interface FastEthernet0/0
 ip address 123.45.250.1 255.255.255.252
 duplex auto
 speed auto

interface FastEthernet0/1
 no ip address
 shutdown
 duplex auto
 speed auto

interface FastEthernet1/0
 no ip address
 shutdown
 duplex auto
 speed auto

interface FastEthernet2/0
 no ip address
 shutdown
 duplex auto
 speed auto

router rip
 version 2
 network 123.0.0.0

ip forward-protocol nd

路由器01：

Router01#show running-config
Building configuration...

Current configuration : 1155 bytes

version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption

hostname Router01

boot-start-marker
boot-end-marker

no aaa new-model
memory-size iomem 5
no ip icmp rate-limit unreachable
ip cef

no ip domain lookup

multilink bundle-name authenticated

archive
 log config
  hidekeys

ip tcp synwait-time 5

interface FastEthernet0/0
 ip address 123.45.250.2 255.255.255.252
 duplex auto
 speed auto

interface FastEthernet0/1
 ip address 123.45.250.5 255.255.255.252
 duplex auto
 speed auto

interface FastEthernet1/0
 ip address 123.45.250.9 255.255.255.252
 duplex auto
 speed auto

interface FastEthernet2/0
 no ip address
 shutdown
 duplex auto
 speed auto

router rip
 version 2
 network 123.0.0.0

ip forward-protocol nd

路由器02：

Router02#show running-config
Building configuration...

Current configuration : 1164 bytes
!
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname Router02
!
boot-start-marker
boot-end-marker

no aaa new-model
memory-size iomem 5
no ip icmp rate-limit unreachable
ip cef

no ip domain lookup
!
multilink bundle-name authenticated

archive
 log config
  hidekeys

ip tcp synwait-time 5

interface FastEthernet0/0
 ip address 123.45.250.6 255.255.255.252
 duplex auto
 speed auto
!
interface FastEthernet0/1
 ip address 123.45.250.13 255.255.255.252
 duplex auto
 speed auto
!
interface FastEthernet1/0
 ip address 123.45.8.1 255.255.254.0
 duplex auto
 speed auto
!
interface FastEthernet2/0
 ip address 123.45.0.1 255.255.252.0
 duplex auto
 speed auto
!
router rip
 version 2
 network 123.0.0.0
!
ip forward-protocol nd

路由器03：

Router03#show running-config
Building configuration...

Current configuration : 1166 bytes
!
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname Router03
!
boot-start-marker
boot-end-marker

no aaa new-model
memory-size iomem 5
no ip icmp rate-limit unreachable
ip cef

no ip domain lookup
!
multilink bundle-name authenticated

archive
 log config
  hidekeys
ip tcp synwait-time 5
!
interface FastEthernet0/0
 ip address 123.45.250.10 255.255.255.252
 duplex auto
 speed auto
!
interface FastEthernet0/1
 ip address 123.45.250.14 255.255.255.252
 duplex auto
 speed auto
!
interface FastEthernet1/0
 ip address 123.45.10.1 255.255.254.0
 duplex auto
 speed auto
!
interface FastEthernet2/0
 ip address 123.45.4.1 255.255.252.0
 duplex auto
 speed auto
!
router rip
 version 2
 network 123.0.0.0
!
ip forward-protocol nd