先把每个主机上配置ip地址和掩码地址，然后在交换机上创建vlan 10和vlan 20，之后用interface gi进入接口
把主机1和2配置为vlan10，主机3和4配置为vlan20。之后在交换机r2上创建vlan 10和vlan 20，之后用interface gi进入接口
把主机1配置为vlan10，主机2配置为vlan20。之后再把两个交换机都用trunk模式。
第一个交换机：
sys
sysname r1
vlan 10
vlan 20
interface gi 1/0/1
port link-type access
port access vlan 10
interface gi 1/0/2
port link-type access
port access vlan 10
interface gi 1/0/3
port link-type access
port access vlan 20
interface gi 1/0/4
port link-type access
port access vlan 20
quit
interface gi 1/0/48
port link-type trunk
port trunk permit vlan 10 20
第二个交换机：
sys
sysname r2
vlan 10
vlan 20
interface gi 1/0/1
port link-type access
port access vlan 10
interface gi 1/0/2
port link-type access
port access vlan 20
qu
interface gi 1/0/48
port link-type trunk
port trunk permit vlan 10 20
来源：https://www.cnblogs.com/bilibili517153/p/10899325.html