02-hcdp-ppt fileshcdp-iernmodule 2-ospfhc120111009 ospf扩展特性

1、OSPF扩展特性Copyright 2012 Huawei Technologies Co., Ltd. All rights reserved.前言本课程介绍OSPF的一些扩展特性。课程内容包括LSDB超载机制，按需电路（DC）特性，Stub路由器等内容。Copyright 2012 Huawei Technologies Co., Ltd. All rights reserved.Page1培训目标学完本课程后，您应该能： 理解LSDB超载机制 理解按需电路上OSPF的特性 理解Stub路由器Copyright 2012 Huawei Technologies

2、Co., Ltd. All rights reserved.Page2LSDB超载的可能性BGPBGPOSPF路由域有些路由器内存容量较小，无法存储太多的AS外部路由信息Copyright 2012 Huawei Technologies Co., Ltd. All rights reserved.Page3LSDB超载机制RTAospfRTA-ospf-1lsdb-overflow-limit 2RTAdisplay ospf briefOSPF ProcessOSPF1 with Router ID Protocol InformationRouterID:

3、Route Tag: 0Border Router:ASMulti-VPN-Instance is not enabledApplications Supported: MPLS Traffic-Engineering Spf-schedule-interval: 5Default ASE parameters: Metric: 1 Tag: Route Preference: 101Type:2ASE SPF RFCRoute Preference: 150Computation Count: 241583 CompatibleOSPF is in LSDB overflow statusA

4、rea Count: 1Nssa Area Count: 0ExChange/Loading Neighbors: 0Copyright 2012 Huawei Technologies Co., Ltd. All rights reserved.Page4按需电路（Demand Circuit）ISDN交换网Area 2Area 0RTBArea 0RTA分支机构Area 1总部网络Copyright 2012 Huawei Technologies Co., Ltd. All rights reserved.Page5按需电路（DC）扩展修改Options字段Copyright 2012

5、Huawei Technologies Co., Ltd. All rights reserved.Page6报文类型DC位设置后的意义何时设置DC位Hello报文用于和按需电路的对端进行协商是否在该链路上启用按需电路的扩展特性只有按需电路上发送的Hello报文才会设置DC位DD报文用于和按需电路的对端进行协商是否在该链路上启用按需电路的扩展特性只有按需电路上发送的DD报文才会设置DC位LSA用于通告其他路由器自己支持按需电路的扩展特性所有自己产生的LSA都要设置此标志第一位第二位DC标志位第四位第五位第六位第七位第八位按需电路（DC）扩展收发Hello报文Copyright 2012 Hua

6、wei Technologies Co., Ltd. All rights reserved.Page7普通点到点链路按需电路（DC）邻接关系建立以前每10秒发送一次Hello报文每隔Poll间隔发送一次Hello报文邻接关系建立以后每10秒发送一次Hello报文不再发送Hello报文按需电路（DC）扩展链路层始终处于Up状态RTAdisplay interface Dialer 0Dialer0 current stateLine protocol currentDescription : HUAWEI,: UPstate :UP (spoofing)Quidway Series, Dial

7、er0 InterfaceThe Maximum Transmit Unit is 1500 bytes, Hold timer is10(sec)Internet Address is Link layer protocol LCP initialPhysical is Dialer/24is PPP5500minutes minutes packetspacketsinputrate 0 bytes/sec, 0 packets/secoutput rate 0 bytes/sec, input, 0 bytes, 0 dropsoutput, 0 bytes, 0 dro

8、ps0packets/secCopyright 2012 Huawei Technologies Co., Ltd. All rights reserved.Page8按需电路（DC）扩展泛洪与老化 LS Age字段，共十六位 DoNotAge标志位，在按需电路上泛洪的LSA设置此位，表示不对此LSA进行老化Copyright 2012 Huawei Technologies Co., Ltd. All rights reserved.Page9第一位后十五位按需电路（DC）扩展稳定时检测邻居状态按需电路DCRTARTB发送应用数据，链路Up12发送自身Router-LSA发送LS Ack，表

9、示处于活动状态3Copyright 2012 Huawei Technologies Co., Ltd. All rights reserved.Page10通告Stub路由器配置OSPF路由域RTALAN性能较差，不适合分担太多流量Copyright 2012 Huawei Technologies Co., Ltd. All rights reserved.Page11RTAospfRTA-ospf-1stub RTA-ospf-1quit RTA通告Stub路由器信息显示RTAdisplay ospf lsdb router self-originateOSPFProcess 1 wit

10、h Router IDArea: Link State DatabaseType Ls id Adv rtr Ls age Len Options seq#:Router 996E 8000000c0x5cf0 chksum:Link count: Link ID:Data:Link Type: P-2-PMetric : 65535Link ID: Data: Link Type: P-2-PMetric : 65535Link ID: Data: Link Type: StubNetMetric : 1Copyright 2012 Huawei Technologies Co., Ltd. All rights reserved.