OSPF-5类LSA和4类LSA

5t4we

# 5类LSA ：外部路由前缀 + ASBR的router_id
IOU5#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/T2
IOU4# 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 count
2.2.2.2         2.2.2.2         1     (DNA) 0x80000005 0x00EBE8 1
3.3.3.3         3.3.3.3         1     (DNA) 0x80000005 0x00AD1E 1
4.4.4.4         4.4.4.4         294         0x80000006 0x00F05A 4
5.5.5.5         5.5.5.5         211         0x80000004 0x006863 3

        Type-5 AS External Link States
Link ID         ADV Router      Age         Seq#       Checksum Tag
10.1.55.0       5.5.5.5         211         0x80000003 0x005FE8 0

IOU4#sh ip ro 10.1.55.55
Routing 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

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# 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/T2 IOU1#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 count 1.1.1.1         1.1.1.1         751         0x80000004 0x00E906 2 2.2.2.2         2.2.2.2         783         0x80000007 0x008C74 1 3.3.3.3         3.3.3.3         756         0x80000007 0x004EA9 1         Summary ASB Link States (Area 2) Link ID         ADV Router      Age         Seq#       Checksum 5.5.5.5         2.2.2.2         783         0x80000003 0x005944 5.5.5.5         3.3.3.3         756         0x80000003 0x003B5E         Type-5 AS External Link States Link ID         ADV Router      Age         Seq#       Checksum Tag 10.1.55.0       5.5.5.5         727         0x80000003 0x005FE8 0

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# 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 10 IOU4#    sh ip ro O 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, Serial2/0 IOU4#sh ip ro 10.1.55.55 Routing 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 20 IOU4#    sh ip ro

leidian00

感谢楼主分享。。。