背景：
网络侧反馈偶尔会出现ospf邻居状态变化：full-> other status -> full.历史原因，线上运行的路由软件有quagga和bird两种。两种路由软件的日志级别配置，打印ospf邻居状态变化的过程。
quagga：
配置选项：
日志文件记录配置
log file /home/work/quagga/logs/ospfd.log
日志打印邻居关系状态变化过程
debug ospf nsm status
配置操作：
mkdir /home/work/quagga/logs -pv
chown -R quagga.quagga /home/work/quagga/
vtysh
conf t
log file /home/work/quagga/logs/ospfd.log
debug ospf nsm status
end
w
exit
*提示：Linux命令行下复制粘贴上述命令即可，热加载生效，无需重启服务。
重启ospfd服务：
service ospfd restart
*提示：此步骤是为了查看效果，如果是线上机器，请勿执行。
日志如下：
[root@localhost ~]# cat /home/work/quagga/logs/ospfd.log
2017/12/15 13:42:11 OSPF: Terminating on signal
2017/12/15 13:42:11 OSPF: NSM[eth1:10.105.251.26:10.105.252.174]: State change Full -> Deleted (KillNbr)
2017/12/15 13:42:11 OSPF: AdjChg: Nbr 10.105.252.174 on eth1:10.105.251.26: Full -> Deleted (KillNbr)
2017/12/15 13:42:11 OSPF: nsm_change_state(10.105.252.174, Full -> Deleted): scheduling new router-LSA origination
2017/12/15 13:42:11 OSPF: ospfTrapIfStateChange trap sent: 10.105.251.26 now Down
2017/12/15 13:42:11 OSPF: interface 10.105.251.26 [5] leave AllSPFRouters Multicast group.
2017/12/15 13:42:11 OSPF: OSPFd 0.99.15 starting: vty@2604
2017/12/15 13:42:11 OSPF: ospfTrapIfStateChange trap sent: 10.105.251.26 now Point-To-Point
2017/12/15 13:42:11 OSPF: interface 10.105.251.26 [5] join AllSPFRouters Multicast group.
2017/12/15 13:42:11 OSPF: NSM[eth1:10.105.251.26:10.105.252.174]: State change Down -> Init (HelloReceived)
2017/12/15 13:42:11 OSPF: NSM[eth1:10.105.251.26:10.105.252.174]: State change Init -> ExStart (2-WayReceived)
2017/12/15 13:42:11 OSPF: Packet[DD]: Neighbor 10.105.252.174 Negotiation done (Slave).
2017/12/15 13:42:11 OSPF: NSM[eth1:10.105.251.26:10.105.252.174]: State change ExStart -> Exchange (NegotiationDone)
2017/12/15 13:42:11 OSPF: NSM[eth1:10.105.251.26:10.105.252.174]: State change Exchange -> Loading (ExchangeDone)
2017/12/15 13:42:11 OSPF: NSM[eth1:10.105.251.26:10.105.252.174]: State change Loading -> Full (LoadingDone)
2017/12/15 13:42:11 OSPF: AdjChg: Nbr 10.105.252.174 on eth1:10.105.251.26: Loading -> Full (LoadingDone)
2017/12/15 13:42:11 OSPF: nsm_change_state(10.105.252.174, Loading -> Full): scheduling new router-LSA origination
bird：
配置选项：
日志文件记录配置
log "/home/work/logs/bird.log" all;
日志打印邻居关系状态变化过程
1. debug protocols { events }; #全局配置
2. debug { events }; #局部配置，在每个protocol中配置
*提示：在1和2中选择其中一个，请注意配置位置，建议采用全局配置。
配置操作：
sed -i '3idebug protocols { events };' /etc/bird.conf #bird配置文件
热加载生效，无需重启服务。
birdcl config
重启bird服务：
kill -9 `ps -ef |grep bir[d]|awk '{print $2}'`
/usr/local/bird/sbin/bird -c /usr/local/bird/etc/bird.conf
*提示：此步骤是为了查看效果，如果是线上机器，请勿执行。
日志如下：
[root@localhost ~]# grep state /home/work/logs/bird.log
2017-12-12 19:03:03 <TRACE> C3_CNC: Changing state of iface veth1.306 from down to ptp
2017-12-12 19:03:03 <TRACE> C3_CTC: Changing state of iface veth1.305 from down to ptp
2017-12-12 19:03:03 <TRACE> C3_BGP: Changing state of iface veth1.308 from down to ptp
2017-12-12 19:03:04 <TRACE> C3_CMN: Changing state of iface veth1.307 from down to ptp
2017-12-12 19:03:06 <TRACE> C3_CTC: Changing state of iface lo from down to ptp
2017-12-12 19:03:15 <TRACE> C3_CTC: Changing state of iface lo from ptp to down
2017-12-12 19:03:15 <TRACE> C3_CTC: Changing state of iface lo from down to ptp
2017-12-12 19:03:15 <TRACE> C3_CTC: Changing state of iface lo from down to ptp
2017-12-12 19:03:35 <TRACE> C3_CMN: Neighbor 10.115.254.49 changes state from " down" to " init".
2017-12-12 19:03:35 <TRACE> C3_CMN: Neighbor 10.115.254.49 changes state from " init" to " 2way".
2017-12-12 19:03:35 <TRACE> C3_CMN: Neighbor 10.115.254.49 changes state from " 2way" to " exstart".
2017-12-12 19:03:35 <TRACE> C3_CNC: Neighbor 10.115.254.45 changes state from " down" to " init".
2017-12-12 19:03:35 <TRACE> C3_CNC: Neighbor 10.115.254.45 changes state from " init" to " 2way".
2017-12-12 19:03:35 <TRACE> C3_CNC: Neighbor 10.115.254.45 changes state from " 2way" to " exstart".
2017-12-12 19:03:35 <TRACE> C3_CTC: Neighbor 10.115.254.41 changes state from " down" to " init".
2017-12-12 19:03:35 <TRACE> C3_CTC: Neighbor 10.115.254.41 changes state from " init" to " 2way".
2017-12-12 19:03:35 <TRACE> C3_CTC: Neighbor 10.115.254.41 changes state from " 2way" to " exstart".
2017-12-12 19:03:35 <TRACE> C3_BGP: Neighbor 10.115.254.53 changes state from " down" to " init".
2017-12-12 19:03:35 <TRACE> C3_BGP: Neighbor 10.115.254.53 changes state from " init" to " 2way".
2017-12-12 19:03:35 <TRACE> C3_BGP: Neighbor 10.115.254.53 changes state from " 2way" to " exstart".
2017-12-12 19:03:36 <TRACE> C3_CMN: Neighbor 10.115.254.49 changes state from " exstart" to "exchange".
2017-12-12 19:03:36 <TRACE> C3_CNC: Neighbor 10.115.254.45 changes state from " exstart" to "exchange".
2017-12-12 19:03:36 <TRACE> C3_CTC: Neighbor 10.115.254.41 changes state from " exstart" to "exchange".
2017-12-12 19:03:36 <TRACE> C3_BGP: Neighbor 10.115.254.53 changes state from " exstart" to "exchange".
2017-12-12 19:03:36 <TRACE> C3_CNC: Neighbor 10.115.254.45 changes state from "exchange" to " loading".
2017-12-12 19:03:36 <TRACE> C3_CMN: Neighbor 10.115.254.49 changes state from "exchange" to " loading".
2017-12-12 19:03:36 <TRACE> C3_CTC: Neighbor 10.115.254.41 changes state from "exchange" to " loading".
2017-12-12 19:03:36 <TRACE> C3_BGP: Neighbor 10.115.254.53 changes state from "exchange" to " loading".
2017-12-12 19:03:37 <TRACE> C3_CTC: Neighbor 10.115.254.41 changes state from " loading" to " full".
2017-12-12 19:03:37 <TRACE> C3_CNC: Neighbor 10.115.254.45 changes state from " loading" to " full".
2017-12-12 19:03:37 <TRACE> C3_CMN: Neighbor 10.115.254.49 changes state from " loading" to " full".
2017-12-12 19:03:37 <TRACE> C3_BGP: Neighbor 10.115.254.53 changes state from " loading" to " full".
参考文档：
quagga官方文档：http://www.nongnu.org/quagga/
bird官方文档：http://bird.network.cz/