hcnp-10天課程版與實驗2ospf擴展特性

1、Copyright 2012 Huawei Technologies Co., Ltd. All rights reserved.OSPF擴展特性前言本課程介紹OSPF的一些擴展特性。課程內(nèi)容包括LSDB超載機制，按需電路（DC）特性，Stub路由器等內(nèi)容。Page1Copyright 2012 Huawei Technologies Co., Ltd. All rights reserved.培訓(xùn)目標學(xué)完本課程后，您應(yīng)該能：理解LSDB超載機制理解按需電路上OSPF的特性理解Stub路由器Page2Copyright 2012 Huawei Technologies Co., Ltd. Al

2、l rights reserved.LSDB超載的可能性O(shè)SPF路由域BGPBGP有些路由器內(nèi)存容量較小，無法存儲太多的AS外部路由信息Page3Copyright 2012 Huawei Technologies Co., Ltd. All rights reserved.LSDB超載機制RTAospfRTA-ospf-1lsdb-overflow-limit 2RTAdisplay ospf briefOSPF Process 1 with Router ID OSPF Protocol InformationRouterID: Border Router:AS Route Tag: 0M

3、ulti-VPN-Instance is not enabledApplications Supported: MPLS Traffic-Engineering Spf-schedule-interval: 5Default ASE parameters: Metric: 1 Tag: 1 Type: 2Route Preference: 10ASE Route Preference: 150 SPF Computation Count: 24 RFC 1583 CompatibleOSPF is in LSDB overflow status Area Count: 1Nssa Area C

4、ount: 0 ExChange/Loading Neighbors: 0Page4Copyright 2012 Huawei Technologies Co., Ltd. All rights reserved.按需電路（Demand Circuit）ISDN交換網(wǎng)RTBArea 0RTAArea 2分支機構(gòu)Area 0Area 1總部網(wǎng)絡(luò)Page5Copyright 2012 Huawei Technologies Co., Ltd. All rights reserved.按需電路（DC）擴展修改Options字段Page6Copyright 2012 Huawei Technologi

5、es Co., Ltd. All rights reserved.第一位第二位DC標志位第四位第五位第六位第七位第八位報文類型DC位設(shè)置后的意義何時設(shè)置DC位Hello報文用于和按需電路的對端進行協(xié)商是否在該鏈路上啟用按需電路的擴展特性只有按需電路上發(fā)送的Hello報文才會設(shè)置DC位DD報文用于和按需電路的對端進行協(xié)商是否在該鏈路上啟用按需電路的擴展特性只有按需電路上發(fā)送的DD報文才會設(shè)置DC位LSA用于通告其他路由器自己支持按需電路的擴展特性所有自己產(chǎn)生的LSA都要設(shè)置此標志按需電路（DC）擴展收發(fā)Hello報文Page7Copyright 2012 Huawei Technologies

6、Co., Ltd. All rights reserved.普通點到點鏈路按需電路（DC）鄰接關(guān)系建立以前每10秒發(fā)送一次Hello報文每隔Poll間隔發(fā)送一次Hello報文鄰接關(guān)系建立以后每10秒發(fā)送一次Hello報文不再發(fā)送Hello報文按需電路（DC）擴展鏈路層始終處于Up狀態(tài)RTAdisplay interface Dialer 0 Dialer0 current state : UPLine protocol current state :UP (spoofing)Description : HUAWEI, Quidway Series, Dialer0 InterfaceThe M

7、aximum Transmit Unit is 1500 bytes, Hold timer is 10(sec) Internet Address is /24Link layer protocol is PPPLCP initialPhysical is Dialer5 minutes input rate 0 bytes/sec, 0 packets/secPage8Copyright 2012 Huawei Technologies Co., Ltd. All rights reserved.5minutesoutput rate 0 bytes/sec, 0 packets/sec0

8、packetsinput, 0 bytes, 0 drops0packetsoutput, 0 bytes, 0 drops按需電路（DC）擴展泛洪與老化第一位后十五位LS Age字段，共十六位DoNotAge標志位，在按需電路上泛洪的 LSA設(shè)置此位，表示不對此LSA進行老化Page9Copyright 2012 Huawei Technologies Co., Ltd. All rights reserved.按需電路（DC）擴展穩(wěn)定時檢測鄰居狀態(tài)RTARTB1發(fā)送應(yīng)用數(shù)據(jù)，鏈路Up按需電路DC2發(fā)送自身Router-LSA3發(fā)送LS Ack，表示處于活動狀態(tài)Page10Copyright

9、 2012 Huawei Technologies Co., Ltd. All rights reserved.通告Stub路由器配置LAN性能較差，不適合分擔(dān)太多流量OSPF路由域RTARTAospfRTA-ospf-1stub RTA-ospf-1quit RTAPage11Copyright 2012 Huawei Technologies Co., Ltd. All rights reserved.通告Stub路由器信息顯示RTAdisplay ospf lsdb router self-originateOSPF Process 1 with Router ID Area: Link

10、 State DatabasePage12Copyright 2012 Huawei Technologies Co., Ltd. All rights reserved.Type:RouterLs id:Adv rtr:Ls age:9Len:96:EOptions seq#: 8000000cchksum: 0 x5cf0 Link count: 6Link ID: Data: Link Type: P-2-PMetric : 65535Link ID: Data: Link Type: P-2-PMetric : 65535Link ID: Data: Link Type: StubNetMetric : 1問題LSDB超載機制中限制的是第幾類LSA？按需電路上如何收發(fā)Hello報文？按需電路上如何老化LSA？Stub路由器連接的網(wǎng)段開銷