帧中继网络中配置OSPF

默认情况下帧中继网络是无法运行OSPF协议的，为什么？【原因】：帧中继（fram-relay）网络属于非广播型多路访问，而OSPF协议规定路由器之间的Hello包是通过组播来传输（组播也属于非广播类型）因此帧中继上默认情况是无法运行OSPF协议的。下面有4种解决方法：•方法一，手工设置ospf网络类型为广播型，在指定fram-relaymap时设置为broadcast（Fram-relay广播）•方法二，默认非广播类型，使用neighbor手工指定邻居，并且手工指定DR为中心路由器（fram-relay非广播）•方法三，手工设置OSPF网络类型为：点到多点型广播型，在指定fram-relaymap时设置为broadcast（fram-relay点对多点广播）•方法四：手工设置OSPF网络类型为：点到多点非广播，使用neighbor手工指定邻居（fram-relay点对多点非广播）再看解决方法之前，先理解以下内容OSPF中的“neighbor”可以手动指定邻居路由器的IP地址，使得它不用组播也能和邻居交换路由信息。哪些网络需要选举DR，哪些网络不用选举DROSPF网络类型特征是否选举DR广播型多路访问以太网、令牌环或FDDI是非广播型多路访问帧中继、X.25、SMDS是点对点PPP、HDLC否点对多点由管理员配置否3.fram-relaymap中broadcast关键词允许路由器通过指定的DLCI号将广播分组分送给所映射的路由器【实验拓扑】：中心-分支帧中继网络拓扑结构

mEO/O1150140!504UnusedCircurt0sp~l40* toso川冷JU-SO/O\mEO/O1150140!504UnusedCircurt0sp~l40* toso川冷JU-SO/O\ljJEO/OOSPFArea0EO/O2叹00«VLAHB50-0.0«VLAtlC方法一，手工设置ospf网络类型为广播型，在指定fram-relaymap时设置为broadcastR1:interfaceL0ipaddress1.0.0.1255.0.0.0!interfaceSerial0/0ipaddress10.0.0.1255.0.0.0encapsulationframe-relayipospfnetworkbroadcastframe-relaymapip10.0.0.4104broadcastframe-relaymapip10.0.0.5105broadcast!routerospf1network0.0.0.0255.255.255.255area0R4:interfaceEthernet0/0ipaddress4.0.0.4255.0.0.0!interfaceSerial0/0ipaddress10.0.0.4255.0.0.0encapsulationframe-relayipospfnetworkbroadcastipospfpriority0frame-relaymapip10.0.0.1401broadcastframe-relaymapip10.0.0.5401noframe-relayinverse-arp!routerospf1network0.0.0.0255.255.255.255area0R5:interfaceEthernet0/0ipaddress5.0.0.5255.0.0.0!interfaceSerial0/0ipaddress10.0.0.5255.0.0.0encapsulationframe-relayipospfnetworkbroadcastipospfpriority0frame-relaymapip10.0.0.1501broadcastframe-relaymapip10.0.0.4501noframe-relayinverse-arp!routerospf1network0.0.0.0255.255.255.255area0方法二，默认非广播类型，使用neighbor手工指定邻居，并且手工指定DR为中心路由器R1:interfaceEthernet0/0ipaddress1.0.0.1255.0.0.0interfaceSerial0/0ipaddress10.0.0.1255.0.0.0encapsulationframe-relayframe-relaymapip10.0.0.4104frame-relaymapip10.0.0.5105!routerospf1network0.0.0.0255.255.255.255area0neighbor10.0.0.4neighbor10.0.0.5R4:interfaceEthernet0/0ipaddress4.0.0.4255.0.0.0!interfaceSerial0/0ipaddress10.0.0.4255.0.0.0encapsulationframe-relayipospfpriority0frame-relaymapip10.0.0.1401frame-relaymapip10.0.0.5401noframe-relayinverse-arp!routerospf1network0.0.0.0255.255.255.255area0R5:interfaceEthernet0/0ipaddress5.0.0.5255.0.0.0!interfaceSerial0/0ipaddress10.0.0.5255.0.0.0encapsulationframe-relayipospfpriority0frame-relaymapip10.0.0.1501frame-relaymapip10.0.0.4501noframe-relayinverse-arp!routerospf1network0.0.0.0255.255.255.255area0方法三，手工设置OSPF网络类型为：点到多点型广播型，在指定fram-relaymap时设置为broadcastR1:interfaceEthernet0/0ipaddress1.0.0.1255.0.0.0!interfaceSerial0/0ipaddress10.0.0.1255.0.0.0encapsulationframe-relayipospfnetworkpoint-to-multipointframe-relaymapip10.0.0.4104broadcastframe-relaymapip10.0.0.5105broadcast!routerospf1network0.0.0.0255.255.255.255area0R4:interfaceEthernet0/0ipaddress4.0.0.4255.0.0.0!interfaceSerial0/0ipaddress10.0.0.4255.0.0.0encapsulationframe-relayipospfnetworkpoint-to-multipointframe-relaymapip10.0.0.1401broadcastnoframe-relayinverse-arp!routerospf1network0.0.0.0255.255.255.255area0R5:interfaceEthernet0/0ipaddress5.0.0.5255.0.0.0!interfaceSerial0/0ipaddress10.0.0.5255.0.0.0encapsulationframe-relayipospfnetworkpoint-to-multipointframe-relaymapip10.0.0.1501broadcastnoframe-relayinverse-arp!routerospf1network0.0.0.0255.255.255.255area0方法四：手工设置OSPF网络类型为：点到多点非广播，使用neighbor手工指定邻居R1:interfaceEthernet0/0ipaddress1.0.0.1255.0.0.0interfaceSerial0/0ipaddress10.0.0.1255.0.0.0encapsulationframe-relayipospfnetworkpoint-to-multipointnon—broadcastframe-relaymapip10.0.0.4104frame-relaymapip10.0.0.5105!routerospf1network0.0.0.0255.255.255.255area0neighbor10.0.0.5neighbor10.0.0.4R4:interfaceEthernet0/0ipaddress4.0.0.4255.0.0.0!interfaceSerial0/0ipaddress10.0.0.4255.0.0.0encapsulationframe-relayipospfnetworkpoint-to-multipointnon-broadcastframe-relaymapip10.0.0.1401noframe-relayinverse-arp!routerospf1network0.0.0.0255.255.255.255area0R5:interfaceEthernet0/0ipaddress5.0.0.5255.0.0.0!int