帮我解说以下命令
interface Vlanif1
ip address dhcp-alloc
#
interface Vlanif2
ip address 192.168.1.216 255.255.255.0
#
interface Vlanif3
ip address 192.168.2.1 255.255.255.0
#
interface MEth0/0/1
#
interface GigabitEthernet0/0/1
port link-type access
port default vlan 3
ntdp enable
ndp enable
bpdu enable
#
interface GigabitEthernet0/0/2
port link-type access
port default vlan 3
ntdp enable
ndp enable
bpdu enable
#
interface GigabitEthernet0/0/3
port link-type access
port default vlan 3
ntdp enable
ndp enable
bpdu enable
...
interface NULL0
#
ip route-static 0.0.0.0 0.0.0.0 192.168.1.1
#
snmp-agent
snmp-agent local-engineid 000007DB7F000001000076C3
snmp-agent sys-info version v3
#
user-interface con 0
user-interface vty 0 4
authentication-mode none
#
return
<Quidway>
<Quidway>
<Quidway>