配置的单臂路由命令如下，PC1也能ping同PC2了，但是求教PC1和PC2怎么才能telnet上S1
interface FastEthernet0/1
switchport access vlan 10
switchport mode access
!
interface FastEthernet0/2
switchport access vlan 20
switchport mode access
interface Vlan1
ip address 192.168.1.1 255.255.255.0
!
interface Vlan10
mac-address 0001.c93a.a201
ip address 192.168.10.254 255.255.255.0
!
interface Vlan20
mac-address 0001.c93a.a202
ip address 192.168.20.254 255.255.255.0
line vty 0 4
password 123
login

1

11

PC1 telnet 192.168.10.254
PC2 telnet 192.168.20.254

你这个不是单臂路由的配置的吧， 你这个是SVI的配置。
telnet 192.168.10.254
telnet 192.168.20.254