Router id的防环：RID无穷自举
上一次这笔记没有在博客里发表成功，今天再试试吧。
个人理解，时间关系，写的比较乱，还请包涵。
拓扑：
提醒：这个拓扑开起来后，看到实验效果后请马上关闭，否则eNSP会死机，死机后可能出现无法预料情况，可以整个关掉eNSP，想用再打开eNSP即可
[R1]dis stp
Protocol Status :Disabled
Protocol Standard :IEEE 802.1s
Version :3
CIST Bridge Priority :32768
MAC address :5489-98b8-3a86
Max age(s) :20
Forward delay(s) :15
Hello time(s) :2
Max hops :20
路由器上STP生成树默认关闭
关键配置：
[R1]dis cur
#
sysname R1
#
router id 91.1.1.1
#
vlan batch 123
#
interface Vlanif123
ip address 123.1.1.1 255.255.255.0
#
interface GigabitEthernet0/0/0
portswitch
shutdown
port hybrid pvid vlan 123
undo port hybrid vlan 1
port hybrid untagged vlan 123
#
interface GigabitEthernet0/0/1
portswitch
shutdown
port hybrid pvid vlan 123
undo port hybrid vlan 1
port hybrid untagged vlan 123
#
ospf 10
area 0.0.0.0
network 123.1.1.1 0.0.0.0
#
[R2]dis cur
#
sysname R2
#
router id 92.2.2.2
#
vlan batch 123
#
interface Vlanif123
ip address 123.1.1.2 255.255.255.0
#
interface GigabitEthernet0/0/1
portswitch
port hybrid pvid vlan 123
undo port hybrid vlan 1
port hybrid untagged vlan 123
这里有个小窍门：如果要更改为access接口会提示错误：renew configuration，这是希望你把接口下所有相关hybrid配置全部删除后再次配置接口
#
interface GigabitEthernet0/0/2
portswitch
port hybrid pvid vlan 123
undo port hybrid vlan 1
port hybrid untagged vlan 123
#
ospf 10
area 0.0.0.0
network 123.1.1.2 0.0.0.0
#
[R3]dis cur
#
sysname R3
#
router id 93.3.3.3
#
vlan batch 123
#
interface Vlanif123
ip address 123.1.1.3 255.255.255.0
#
interface GigabitEthernet0/0/0
portswitch
port hybrid pvid vlan 123
undo port hybrid vlan 1
port hybrid untagged vlan 123
#
interface GigabitEthernet0/0/2
portswitch
port hybrid pvid vlan 123
undo port hybrid vlan 1
port hybrid untagged vlan 123
#
ospf 10
area 0.0.0.0
network 123.1.1.3 0.0.0.0
#
实验结果建议用：display ospf error查看router id confusion结果
这个实验说明RID也具备防环功能，原因是二层打破了hello只有一跳的限制，自己收到自己的hello报文从而报错，说明出现环路
