#5类LSA：外部路由前缀+ASBR的router_idIOU5#shipospfdataextOSPFRouterwithID(5.5.5.5)(ProcessID1)Type-5ASExterna
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# 5类LSA ：外部路由前缀 + ASBR的router_idIOU5#sh ip ospf data ext OSPF Router with ID (5.5.5.5) (Process ID 1) Type-5 AS External Link States LS age: 71 Options: (No TOS-capability, DC, Upward) LS Type: AS External Link Link State ID: 10.1.55.0 (External Network Number ) Advertising Router: 5.5.5.5 LS Seq Number: 80000002 Checksum: 0x61E7 Length: 36 Network Mask: /24 Metric Type: 2 (Larger than any link state path) MTID: 0 Metric: 20 # 种子metric Forward Address: 0.0.0.0 External Route Tag: 0 # 区域内路由OE T5 + T1/T2IOU4# sh ip ospf data OSPF Router with ID (4.4.4.4) (Process ID 1) Router Link States (Area 0)Link ID ADV Router Age Seq# Checksum Link count2.2.2.2 2.2.2.2 1 (DNA) 0x80000005 0x00EBE8 13.3.3.3 3.3.3.3 1 (DNA) 0x80000005 0x00AD1E 14.4.4.4 4.4.4.4 294 0x80000006 0x00F05A 45.5.5.5 5.5.5.5 211 0x80000004 0x006863 3 Type-5 AS External Link StatesLink ID ADV Router Age Seq# Checksum Tag10.1.55.0 5.5.5.5 211 0x80000003 0x005FE8 0IOU4#sh ip ro 10.1.55.55Routing entry for 10.1.55.0/24 Known via "ospf 1", distance 110, metric 20, type extern 2, forward metric 64 Last update from 10.1.45.5 on Serial2/1, 01:15:51 ago Routing Descriptor Blocks: * 10.1.45.5, from 5.5.5.5, 01:15:51 ago, via Serial2/1 Route metric is 20, traffic share count is 1
# 4类LSA： ASBR的router_id + 本区域ABR的router_id IOU1#sh ip ospf da asbr-summary OSPF Router with ID (1.1.1.1) (Process ID 1) Summary ASB Link States (Area 2) Routing Bit Set on this LSA in topology Base with MTID 0 LS age: 840 Options: (No TOS-capability, DC, Upward) LS Type: Summary Links(AS Boundary Router) Link State ID: 5.5.5.5 (AS Boundary Router address) Advertising Router: 2.2.2.2 LS Seq Number: 80000003 Checksum: 0x5944 Length: 28 Network Mask: /0 MTID: 0 Metric: 128 Routing Bit Set on this LSA in topology Base with MTID 0 LS age: 814 Options: (No TOS-capability, DC, Upward) LS Type: Summary Links(AS Boundary Router) Link State ID: 5.5.5.5 (AS Boundary Router address) Advertising Router: 3.3.3.3 LS Seq Number: 80000003 Checksum: 0x3B5E Length: 28 Network Mask: /0 MTID: 0 Metric: 128 # 域间路由： T5 + T4 + T1/T2IOU1#sh ip ospf da OSPF Router with ID (1.1.1.1) (Process ID 1) Router Link States (Area 2)Link ID ADV Router Age Seq# Checksum Link count1.1.1.1 1.1.1.1 751 0x80000004 0x00E906 22.2.2.2 2.2.2.2 783 0x80000007 0x008C74 13.3.3.3 3.3.3.3 756 0x80000007 0x004EA9 1 Summary ASB Link States (Area 2)Link ID ADV Router Age Seq# Checksum5.5.5.5 2.2.2.2 783 0x80000003 0x0059445.5.5.5 3.3.3.3 756 0x80000003 0x003B5E Type-5 AS External Link StatesLink ID ADV Router Age Seq# Checksum Tag10.1.55.0 5.5.5.5 727 0x80000003 0x005FE8 0
# 5类LSA的外部路由OE2选择： # 1、外部路由的metric小优先IOU1(config-router)#redistribute connected route-map loop metric 10IOU4# sh ip roO E2 10.1.55.0/24 [110/10] via 10.1.234.3, 00:00:03, Serial2/0 [110/10] via 10.1.234.2, 00:00:03, Serial2/0IOU4#sh ip ro 10.1.55.55Routing entry for 10.1.55.0/24 Known via "ospf 1", distance 110, metric 10, type extern 2, forward metric 74 Last update from 10.1.234.2 on Serial2/0, 00:04:44 ago Routing Descriptor Blocks: * 10.1.234.3, from 1.1.1.1, 00:04:44 ago, via Serial2/0 Route metric is 10, traffic share count is 1 10.1.234.2, from 1.1.1.1, 00:04:44 ago, via Serial2/0 Route metric is 10, traffic share count is 1 # 2、外部路由的metric相等，forward metric小优先；IOU1(config-router)#redistribute connected route-map loop metric 20IOU4# sh ip ro.
