OSPF中的DR和BDR角色

摘要

广播节目就像一个人大声说话，让整个房间都听得到。在互联网中，一台设备可以向同一广播域内的所有设备发送广播节目。但如果我们想和其中一台设备通信，该怎么办呢？这就需要根据MAC地址进行通信。虽然IP地址会变化，但MAC地址是唯一的。

正文

　　前文大家了解了OSPF创建隔壁邻居关联的标准，回望请参照https://www.cnblogs.com/qiuhom-1874/p/15032907.html；今日大家来聊一聊OSPF中的DR和BDR；

　　在说DR和BDR以前大家先来掌握下OSPF的网络类型；

　　最先OSPF的网络类型是根据插口来区划，次之OSPF的网络类型是根据插口的二层封裝报文格式的方法开展了区划，默认设置状况下OSPF把插口二层是以太网接口封裝的互联网称之为广播节目种类，把插口二层是PPP或是HDLC封裝的互联网称之为点和点种类；

　　在日常生活中，广播节目便是一个人讲话，在同一个屋子里的别人都能够听见；在互联网里，广播节目和这一相近；一个计算机设备在一个广播域推送一条广播节目报文格式，在同一个广播域的全部机器设备都能接到该机器设备的广播节目；这样一来我们要想和在其中的一台机器设备通信如何通信呢？在二层为以太网接口封裝的广播节目种类互联网里，它是根据二层以太网接口封裝总体目标MAC和源MAC；其缘故是ip详细地址是转变的，假如单纯性的应用ip详细地址不能够精确的标志某一台机器设备（由于ip详细地址是转变的），而MAC地址是机器设备的硬件配置详细地址，这一详细地址是机器设备在出厂时就固定不动了，更何况不容易产生变化；因此明确一台机器设备的唯一性，我们可以根据MAC地址；拥有通讯彼此的mac详细地址再融合三层的ip详细地址，大家就可以精确的将相匹配数据文件发给另一方；

　　针对点和点种类的互联网，其二层就不用封裝MAC地址，一条链接上就仅有2个节点，在A节点传送数据B节点就一定能接到；

　　提醒：广播节目种类的插口是以太网接口类型接口（便是大家经常见到的网络接口），而点和点种类的插口是串口通信；

　　在点到点种类的互联网中，根据插口封裝的不一样又可以分非广播节目多通道浏览和点至多一点，如下图

　　提醒：默认设置状况下，OSPF觉得帧中继（FR）、异步传输（ATM）的网络类型为NBMA；在帧中继互联网里非广播节目多通道浏览和以太网接口中的广播节目种类，二者有一个同样的特性，便是都能够接好几个机器设备；不同之处是以太网接口二层封裝必须封裝mac详细地址，适用广播节目推送，而帧中继互联网二层不用封裝mac详细地址，其缘故是它不兼容广播节目；不兼容广播节目就代表着在ospf里不兼容组播；不兼容组播换句话说帧中继互联网里，ospf只有根据单播的方法创建隔壁邻居；

　　试验：如下图2个拓扑结构，R1和R2为以太网接口类型接口，R3和R4为串口通信插口，在2个试验自然环境中配备ospf，抓包软件看一下二者发送至hello包有哪些不一样

　　配备R1

sys
sys R1
int g0/0/0
ip add 12.0.0.1 24
ospf 1 router-id 1.1.1.1
area 0
net 12.0.0.1 0.0.0.0
dis ip int b

View Code

　　配备R2

sys
sys R2
int g0/0/0
ip add 12.0.0.2 24
ospf 1 router-id 2.2.2.2
area 0
net 12.0.0.2 0.0.0.0
dis ip int b

View Code

　　配备R3

sys
sys R3
int s4/0/0
ip add 34.0.0.3 24
ospf 1 router-id 3.3.3.3
area 0
net 34.0.0.3 0.0.0.0
dis ip int b

View Code

　　配备R4

sys
sys R4
int s4/0/0
ip add 34.0.0.4 24
ospf 1 router-id 4.4.4.4
area 0
net 34.0.0.4 0.0.0.0
dis ip int b

View Code

　　在R1或R2上抓包软件

　　在R3或R4上抓包软件

　　提醒：默认设置状况串口通信链接的二层封裝为ppp种类，这儿抓包软件就挑选ppp链路种类就可以；

　　提醒：从上边的抓包软件状况能够见到，在以太网接口封种类的网络空间下抓包软件，其二层封裝了总体目标mac和源mac，而在点和点种类的网络空间下抓包软件，其二层就并不是应用以太网协议只是用ppp协议，而且数据文件里边都没有封裝mac详细地址；

　　认证：查询相匹配ospf网络种类

　　在R1或R2上认证有关插口的网络类型

　　在R3或R4上认证有关插口的网络类型

　　变更R3的s4/0/0的链接封裝为FR，看一下相匹配的接口方式是啥

　　提醒：能够见到改动了R3的s4/0/0插口的封裝为FR之后，相匹配ospf就down没了；而且相匹配插口的种类就变为了NBMA（非广播节目多通道浏览）；

　　OSPF DR和BDR

　　DR和BDR的功效

　　在以上的网络类型中，在多通道浏览网络类型中跑OSPF，每一个无线路由器都是会和别的无线路由器创建隔壁邻居，一个无线路由器推送一条链接升级，别的无线路由器都是会跟随确定，这样一来，每一个无线路由器都需要历经两组的互动和确定，在一定水平上面产生无线路由器的特性的花销（hello包，DD，LSR，LSU，LSACK这种包太多，提升无线路由器的解决工作压力，进而造成无线路由器的特性减少）；为了更好地减少数据文件的互换，在OSPF时会大选DR和BDR；如下图

　　提醒：广播节目型互联网MA和NBMA互联网中，为了更好地降低临接关联的总数，进而降低数据文件互换，频次，最后节约网络带宽，减少对无线路由器解决工作能力的工作压力，大选DR和BDR。

　　有关专业术语简述

　　DR：Designed Router，特定无线路由器，相近组长、经理；

　　BDR：Backup DR，预留DR，相近副班长、总经理；

　　DRouthers：相近一般学员、普通职工；

　　三者的关联：DR、BDR、DRothers中间都维持临接关联（Full），DRothers中间维持隔壁邻居关联（Two-Way）；

　　通讯地址：224.0.0.6向DR和BDR推送链接情况升级，224.0.0.5向全部OSPF无线路由器推送；

　　DR大选标准

　　1、最先较为Hello报文格式中带上的优先，优先范畴是0-255，默认设置状况下都是1；优先最大的被大选为DR，优先次高的被大选为BDR；优先为0的不参加大选；

　　2、假如优先同样的状况下，较为Router id，router id 越大越优先选择；

　　3、大选不具备占领性，除非是当DR和BDR都无效或重新启动OSPF过程；

　　提醒：DRothers的LSU向DR或BDR根据224.0.0.6推送，随后DR接到DRothers发送至LSU之后，会将相匹配的LSU根据224.0.0.5向别的无线路由器推送，别的无线路由器接到DR推送LSU之后，BDR向224.0.0.5立即确定，而DBothers则根据224.0.0.6向DR确定；汇总一句话就是以DR或BDR传出的数据文件全是寄往224.0.0.5，DR和BDR都是会监视224.0.0.6这一详细地址；DRothers传出的数据信息会根据224.0.0.6向DR或BDR推送；

　　试验：如下图，各大网站运作ospf，看一下相匹配的数据文件会那么推送，相匹配无线路由器中间是啥关联

　　配备R1

sys
sys R1
int g0/0/0
ip add 1.0.0.1 24
ospf 1 router-id 1.1.1.1
a 0
net 1.0.0.0 0.0.0.255
dis ip int b
dis ospf peer brief

View Code

　　在R1上查询g0/0/0的插口信息内容，看一下哪位DR和BDR

　　提醒：能够见到只配备了R1上的OSPF之后，相匹配DR便是它自身，由于这时沒有别的机器设备和它竟选DR，因此仅有它是DR；针对BDR而言，它不清楚，由于现阶段就仅有它自身在ospf里边，沒有见到别的机器设备；

　　配备R2

sys
sys R2
int g0/0/0
ip add 1.0.0.2 24
ospf 1 router-id 2.2.2.2
a 0
net 1.0.0.0 0.0.0.255
dis ip int b
dis ospf peer brief

View Code

<Huawei>sys
Enter system view, return user view with Ctrl Z.
[Huawei]sys R2
[R2]int g0/0/0
[R2-GigabitEthernet0/0/0]ip add 1.0.0.2 24
[R2-GigabitEthernet0/0/0]ospf 1 rout
Jul 24 2021 12:08:39-08:00 R2 %IFNET/4/LINK_STATE(l)[0]:The line protocol IP on the interface GigabitEthernet0/0/0 has entered the UP state. 
[R2-GigabitEthernet0/0/0]ospf 1 router-id 2.2.2.2
[R2-ospf-1]a 0
[R2-ospf-1-area-0.0.0.0]net 1.0.0.0 0.0.0.255
[R2-ospf-1-area-0.0.0.0]dis ip int b
*down: administratively down
^down: standby
(l): loopback
(s): spoofing
The number of interface that is UP in Physical is 2
The number of interface that is DOWN in Physical is 2
The number of interface that is UP in Protocol is 2
The number of interface that is DOWN in Protocol is 2

Interface                         IP Address/Mask      Physical   Protocol  
GigabitEthernet0/0/0              1.0.0.2/24           up         up        
GigabitEthernet0/0/1              unassigned           down       down      
GigabitEthernet0/0/2              unassigned           down       down      
NULL0                             unassigned           up         up(s)     
[R2-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:08:44-08:00 R2 %OSPF/4/NBR_CHANGE_E(l)[1]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=1.0.0.1, NeighborEvent=HelloReceived, NeighborPreviousState=Down, NeighborCurrentState=Init) 
[R2-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:08:44-08:00 R2 %OSPF/4/NBR_CHANGE_E(l)[2]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=1.0.0.1, NeighborEvent=2WayReceived, NeighborPreviousState=Init, NeighborCurrentState=2Way) 
[R2-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:08:44-08:00 R2 %OSPF/4/NBR_CHANGE_E(l)[3]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=1.0.0.1, NeighborEvent=AdjOk?, NeighborPreviousState=2Way, NeighborCurrentState=ExStart) 
[R2-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:08:44-08:00 R2 %OSPF/4/NBR_CHANGE_E(l)[4]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=1.0.0.1, NeighborEvent=NegotiationDone, NeighborPreviousState=ExStart, NeighborCurrentState=Exchange) 
[R2-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:08:44-08:00 R2 %OSPF/4/NBR_CHANGE_E(l)[5]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=1.0.0.1, NeighborEvent=ExchangeDone, NeighborPreviousState=Exchange, NeighborCurrentState=Loading) 
[R2-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:08:44-08:00 R2 %OSPF/4/NBR_CHANGE_E(l)[6]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=1.0.0.1, NeighborEvent=LoadingDone, NeighborPreviousState=Loading, NeighborCurrentState=Full) 
[R2-ospf-1-area-0.0.0.0]dis ospf peer brief

         OSPF Process 1 with Router ID 2.2.2.2
                  Peer Statistic Information
 ----------------------------------------------------------------------------
 Area Id          Interface                        Neighbor id      State    
 0.0.0.0          GigabitEthernet0/0/0             1.1.1.1          Full        
 ----------------------------------------------------------------------------
[R2-ospf-1-area-0.0.0.0]

　　提醒：能够见到当R2配备好ospf之后，它会和R1先创建其临接关联；

　　再度在R1上查询g0/0/0的插口信息内容，看一下这时哪位DR和BDR

　　提醒：这时能够见到DR是R1的插口ip详细地址，BDR是R2的插口详细地址；

　　配备R3

sys
sys R3
int g0/0/0
ip add 1.0.0.3 24
ospf 1 router-id 3.3.3.3
a 0
net 1.0.0.0 0.0.0.255
dis ip int b
dis ospf peer brief

View Code

<Huawei>sys
Enter system view, return user view with Ctrl Z.
[Huawei]sys R3
[R3]int g0/0/0
[R3-GigabitEthernet0/0/0]ip add 1.0.0.3 24
Jul 24 2021 12:14:41-08:00 R3 %IFNET/4/LINK_STATE(l)[0]:The line protocol IP on the interface GigabitEthernet0/0/0 has entered the UP state. 
[R3-GigabitEthernet0/0/0]ospf 1 router-id 3.3.3.3
[R3-ospf-1]a 0
[R3-ospf-1-area-0.0.0.0]net 1.0.0.0 0.0.0.255
[R3-ospf-1-area-0.0.0.0]dis ip int b
*down: administratively down
^down: standby
(l): loopback
(s): spoofing
The number of interface that is UP in Physical is 2
The number of interface that is DOWN in Physical is 2
The number of interface that is UP in Protocol is 2
The number of interface that is DOWN in Protocol is 2

Interface                         IP Address/Mask      Physical   Protocol  
GigabitEthernet0/0/0              1.0.0.3/24           up         up        
GigabitEthernet0/0/1              unassigned           down       down      
GigabitEthernet0/0/2              unassigned           down       down      
NULL0                             unassigned           up         up(s)     
[R3-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:14:45-08:00 R3 %OSPF/4/NBR_CHANGE_E(l)[1]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=1.0.0.1, NeighborEvent=HelloReceived, NeighborPreviousState=Down, NeighborCurrentState=Init) 
[R3-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:14:45-08:00 R3 %OSPF/4/NBR_CHANGE_E(l)[2]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=1.0.0.1, NeighborEvent=2WayReceived, NeighborPreviousState=Init, NeighborCurrentState=2Way) 
[R3-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:14:46-08:00 R3 %OSPF/4/NBR_CHANGE_E(l)[3]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=2.0.0.1, NeighborEvent=HelloReceived, NeighborPreviousState=Down, NeighborCurrentState=Init) 
[R3-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:14:46-08:00 R3 %OSPF/4/NBR_CHANGE_E(l)[4]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=2.0.0.1, NeighborEvent=2WayReceived, NeighborPreviousState=Init, NeighborCurrentState=2Way) 
[R3-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:14:46-08:00 R3 %OSPF/4/NBR_CHANGE_E(l)[5]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=1.0.0.1, NeighborEvent=AdjOk?, NeighborPreviousState=2Way, NeighborCurrentState=ExStart) 
[R3-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:14:46-08:00 R3 %OSPF/4/NBR_CHANGE_E(l)[6]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=2.0.0.1, NeighborEvent=AdjOk?, NeighborPreviousState=2Way, NeighborCurrentState=ExStart) 
[R3-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:14:46-08:00 R3 %OSPF/4/NBR_CHANGE_E(l)[7]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=1.0.0.1, NeighborEvent=NegotiationDone, NeighborPreviousState=ExStart, NeighborCurrentState=Exchange) 
[R3-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:14:46-08:00 R3 %OSPF/4/NBR_CHANGE_E(l)[8]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=2.0.0.1, NeighborEvent=NegotiationDone, NeighborPreviousState=ExStart, NeighborCurrentState=Exchange) 
[R3-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:14:46-08:00 R3 %OSPF/4/NBR_CHANGE_E(l)[9]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=1.0.0.1, NeighborEvent=ExchangeDone, NeighborPreviousState=Exchange, NeighborCurrentState=Loading) 
[R3-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:14:46-08:00 R3 %OSPF/4/NBR_CHANGE_E(l)[10]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=1.0.0.1, NeighborEvent=LoadingDone, NeighborPreviousState=Loading, NeighborCurrentState=Full) 
[R3-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:14:46-08:00 R3 %OSPF/4/NBR_CHANGE_E(l)[11]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=2.0.0.1, NeighborEvent=ExchangeDone, NeighborPreviousState=Exchange, NeighborCurrentState=Loading) 
[R3-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:14:46-08:00 R3 %OSPF/4/NBR_CHANGE_E(l)[12]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=2.0.0.1, NeighborEvent=LoadingDone, NeighborPreviousState=Loading, NeighborCurrentState=Full) 
[R3-ospf-1-area-0.0.0.0]dis ospf peer brief

         OSPF Process 1 with Router ID 3.3.3.3
                  Peer Statistic Information
 ----------------------------------------------------------------------------
 Area Id          Interface                        Neighbor id      State    
 0.0.0.0          GigabitEthernet0/0/0             1.1.1.1          Full        
 0.0.0.0          GigabitEthernet0/0/0             2.2.2.2          Full        
 ----------------------------------------------------------------------------
[R3-ospf-1-area-0.0.0.0]

　　提醒：能够见到当R3配备好之后，相匹配R3和R1和R2都创建起临接关联；

　　查询R3g0/0/0插口信息内容，看一下DR和BDR转变沒有？

　　提醒：往往DR和BDR沒有产生变化，其缘故是ospf早已选好啦DR和BDR，而DR和BDR的大选是是非非占领性，一旦选好，就不会改变了，除非是重新启动ospf过程（全部无线路由器）来开启DR和BDR的再次大选；

　　配备R4

sys
sys R4
int g0/0/0
ip add 1.0.0.4 24
ospf 1 router-id 4.4.4.4
a 0
net 1.0.0.0 0.0.0.255
dis ip int b
dis ospf peer brief

View Code

<Huawei>sys
Enter system view, return user view with Ctrl Z.
[Huawei]sys R4
[R4]int g0/0/0
[R4-GigabitEthernet0/0/0]ip add 1.0.0.4 24
Jul 24 2021 12:20:57-08:00 R4 %IFNET/4/LINK_STATE(l)[0]:The line protocol IP on the interface GigabitEthernet0/0/0 has entered the UP state. 
[R4-GigabitEthernet0/0/0]ospf 1 router-id 4.4.4.4
[R4-ospf-1]a 0
[R4-ospf-1-area-0.0.0.0]net 1.0.0.0 0.0.0.255
[R4-ospf-1-area-0.0.0.0]dis ip int b
*down: administratively down
^down: standby
(l): loopback
(s): spoofing
The number of interface that is UP in Physical is 2
The number of interface that is DOWN in Physical is 2
The number of interface that is UP in Protocol is 2
The number of interface that is DOWN in Protocol is 2

Interface                         IP Address/Mask      Physical   Protocol  
GigabitEthernet0/0/0              1.0.0.4/24           up         up        
GigabitEthernet0/0/1              unassigned           down       down      
GigabitEthernet0/0/2              unassigned           down       down      
NULL0                             unassigned           up         up(s)     
[R4-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:21:02-08:00 R4 %OSPF/4/NBR_CHANGE_E(l)[1]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=2.0.0.1, NeighborEvent=HelloReceived, NeighborPreviousState=Down, NeighborCurrentState=Init) 
[R4-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:21:02-08:00 R4 %OSPF/4/NBR_CHANGE_E(l)[2]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=2.0.0.1, NeighborEvent=2WayReceived, NeighborPreviousState=Init, NeighborCurrentState=2Way) 
[R4-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:21:02-08:00 R4 %OSPF/4/NBR_CHANGE_E(l)[3]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=2.0.0.1, NeighborEvent=AdjOk?, NeighborPreviousState=2Way, NeighborCurrentState=ExStart) 
[R4-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:21:02-08:00 R4 %OSPF/4/NBR_CHANGE_E(l)[4]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=2.0.0.1, NeighborEvent=NegotiationDone, NeighborPreviousState=ExStart, NeighborCurrentState=Exchange) 
[R4-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:21:02-08:00 R4 %OSPF/4/NBR_CHANGE_E(l)[5]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=2.0.0.1, NeighborEvent=ExchangeDone, NeighborPreviousState=Exchange, NeighborCurrentState=Loading) 
[R4-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:21:02-08:00 R4 %OSPF/4/NBR_CHANGE_E(l)[6]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=2.0.0.1, NeighborEvent=LoadingDone, NeighborPreviousState=Loading, NeighborCurrentState=Full) 
[R4-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:21:04-08:00 R4 %OSPF/4/NBR_CHANGE_E(l)[7]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=1.0.0.1, NeighborEvent=HelloReceived, NeighborPreviousState=Down, NeighborCurrentState=Init) 
[R4-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:21:04-08:00 R4 %OSPF/4/NBR_CHANGE_E(l)[8]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=1.0.0.1, NeighborEvent=2WayReceived, NeighborPreviousState=Init, NeighborCurrentState=2Way) 
[R4-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:21:04-08:00 R4 %OSPF/4/NBR_CHANGE_E(l)[9]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=1.0.0.1, NeighborEvent=AdjOk?, NeighborPreviousState=2Way, NeighborCurrentState=ExStart) 
[R4-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:21:05-08:00 R4 %OSPF/4/NBR_CHANGE_E(l)[10]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=1.0.0.1, NeighborEvent=NegotiationDone, NeighborPreviousState=ExStart, NeighborCurrentState=Exchange) 
[R4-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:21:05-08:00 R4 %OSPF/4/NBR_CHANGE_E(l)[11]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=1.0.0.1, NeighborEvent=ExchangeDone, NeighborPreviousState=Exchange, NeighborCurrentState=Loading) 
[R4-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:21:05-08:00 R4 %OSPF/4/NBR_CHANGE_E(l)[12]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=1.0.0.1, NeighborEvent=LoadingDone, NeighborPreviousState=Loading, NeighborCurrentState=Full) 
[R4-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:21:06-08:00 R4 %OSPF/4/NBR_CHANGE_E(l)[13]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=3.0.0.1, NeighborEvent=HelloReceived, NeighborPreviousState=Down, NeighborCurrentState=Init) 
[R4-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:21:06-08:00 R4 %OSPF/4/NBR_CHANGE_E(l)[14]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=3.0.0.1, NeighborEvent=2WayReceived, NeighborPreviousState=Init, NeighborCurrentState=2Way) 
[R4-ospf-1-area-0.0.0.0]dis ospf peer brief
Jul 24 2021 12:21:06-08:00 R4 %OSPF/4/NBR_CHANGE_E(l)[15]:Neighbor changes event: neighbor status changed. (ProcessId=256, NeighborAddress=3.0.0.1, NeighborEvent=AdjOk?, NeighborPreviousState=2Way, NeighborCurrentState=2Way) 
[R4-ospf-1-area-0.0.0.0]dis ospf peer brief

         OSPF Process 1 with Router ID 4.4.4.4
                  Peer Statistic Information
 ----------------------------------------------------------------------------
 Area Id          Interface                        Neighbor id      State    
 0.0.0.0          GigabitEthernet0/0/0             1.1.1.1          Full        
 0.0.0.0          GigabitEthernet0/0/0             2.2.2.2          Full        
 0.0.0.0          GigabitEthernet0/0/0             3.3.3.3          2-Way       
 ----------------------------------------------------------------------------
[R4-ospf-1-area-0.0.0.0]

　　提醒：能够见到当R4配备好之后，相匹配R4和R1（DR），R2（BDR）是临接关联；而和R3（DRothers）创建的隔壁邻居关联；

　　认证：在R1上公布升级，抓包软件看一下相匹配的数据文件会如何推送和确定？

　　提醒：能够见到当R1（DR）推送LSU时，它会立即向224.0.0.5推送；在其中R2（BDR）向224.0.0.5确定；R3（DRothers）和R4（DRothers）向224.0.0.6确定；

　　认证：在R2上推送LSU，看一下相匹配数据文件会那么推送和确定的呢？

　　提醒：能够见到当R2（BDR）推送LSU时，它和R1推送LSU一样立即向224.0.0.5推送LSU，相匹配R1（DR）立即向224.0.0.5确定；R3、R4（DRother）向224.0.0.6确定；

　　认证：当R3推送LSU，看一下相匹配数据文件会那么推送和确定呢？

　　提醒：能够见到当R3（DRother）推送LSU时，它最先会把LSU根据224.0.0.6向R1（DR）推送，当R1（DR）接到R3推送的LSU，它会根据224.0.0.5向别的无线路由器推送LSU（不容易再发给R3）；R2（BDR）接到LSU向224.0.0.5确定，R4（DRother）向224.0.0.6确定；

　　认证：当R4 推送LSU时，看一下相匹配数据文件会如何推送和确定呢？

　　提醒：能够见到R4（DRother）推送LSU和R3（DRother）推送LSU一样；最先它会把LSU发给R1（DR），随后由R1（DR）再向别的无线路由器推送LSU；BDR（R2）立即向224.0.0.5确定；DRother（R3）向224.0.0.6确定；

　　认证：各大网站重新启动ospf过程，看一下相匹配的DR和BDR是不是会再次大选？

　　提醒：能够见到4个无线路由器各自重启了ospf之后，重设ospf 过程之后，R4入选为DR，R3入选为BDR；由于重新启动ospf过程相匹配的隔壁邻居和临接关联又再次创建，这时4个无线路由器最先会较为相匹配的hello包内的优先，默认设置状况下优先都是1 ，这时优先一样，会较为router id，router id谁大谁便是DR，次近于就为BDR，剩余沒有被大选成DR或BDR的就沦落DRother；R4的router id为4.4.4.4 是4个无线路由器中较大的，因此R4入选DR，R3的router id为3.3.3.3 ，第二大，因此入选BDR；

创作者：Linux-1874

来源：https://www.cnblogs.com/qiuhom-1874/

文中著作权归创作者和博客园一共有，热烈欢迎转截，但没经创作者愿意务必保存此段申明，且在文章内容网页页面显著部位得出全文联接，不然保存追责法律依据的支配权.

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