OSPF実験（エリア分割編）
エリア設計
ルーティングテーブルの変化
- エリア分割前
R1# sh ip ospf ro
============ OSPF network routing table ============
N 172.20.12.0/24 [10] area: 0.0.0.0
directly attached to eth1
N 172.20.13.0/24 [10] area: 0.0.0.0
directly attached to eth2
N 172.20.23.0/24 [20] area: 0.0.0.0
via 172.20.12.2, eth1
via 172.20.13.3, eth2
N 172.20.24.0/24 [20] area: 0.0.0.0
via 172.20.12.2, eth1
N 172.20.35.0/24 [20] area: 0.0.0.0
via 172.20.13.3, eth2
============ OSPF router routing table =============
============ OSPF external routing table ===========
- エリア分割後
R1# sh ip ospf ro
============ OSPF network routing table ============
N 172.20.12.0/24 [10] area: 0.0.0.0
directly attached to eth1
N 172.20.13.0/24 [10] area: 0.0.0.0
directly attached to eth2
N 172.20.23.0/24 [20] area: 0.0.0.0
via 172.20.12.2, eth1
via 172.20.13.3, eth2
N IA 172.20.24.0/24 [20] area: 0.0.0.0
via 172.20.12.2, eth1
N IA 172.20.35.0/24 [20] area: 0.0.0.0
via 172.20.13.3, eth2
============ OSPF router routing table =============
R 2.2.2.2 [10] area: 0.0.0.0, ABR
via 172.20.12.2, eth1
R 3.3.3.3 [10] area: 0.0.0.0, ABR
via 172.20.13.3, eth2
============ OSPF external routing table ===========.24.0と.35.0の経路に他のエリアの経路を示すIAマークがついた
そしてルータのルーティングテーブルにABRが出現
LSDBの変化
- エリア分割前
R1# sh ip ospf data
OSPF Router with ID (1.1.1.1)
Router Link States (Area 0.0.0.0)
Link ID ADV Router Age Seq# CkSum Link count
1.1.1.1 1.1.1.1 1718 0x80000258 0x5141 2
2.2.2.2 2.2.2.2 384 0x8000037b 0x067a 3
3.3.3.3 3.3.3.3 150 0x80000288 0x3817 3
4.4.4.4 4.4.4.4 387 0x80000385 0x5593 1
5.5.5.5 5.5.5.5 151 0x80000273 0x3ba0 1
Net Link States (Area 0.0.0.0)
Link ID ADV Router Age Seq# CkSum
172.20.12.2 2.2.2.2 335 0x80000265 0xae62
172.20.13.3 3.3.3.3 1714 0x80000034 0x1624
172.20.23.3 3.3.3.3 1306 0x80000003 0x2c31
172.20.24.4 4.4.4.4 391 0x80000001 0x2f26
172.20.35.5 5.5.5.5 156 0x80000001 0xe15b
Summary Link States (Area 0.0.0.0)
- エリア分割後
R1# sh ip ospf data
OSPF Router with ID (1.1.1.1)
Router Link States (Area 0.0.0.0)
Link ID ADV Router Age Seq# CkSum Link count
1.1.1.1 1.1.1.1 1146 0x80000258 0x5141 2
2.2.2.2 2.2.2.2 723 0x80000379 0xb59c 2
3.3.3.3 3.3.3.3 733 0x80000281 0xa499 2
Net Link States (Area 0.0.0.0)
Link ID ADV Router Age Seq# CkSum
172.20.12.2 2.2.2.2 1563 0x80000264 0xb061
172.20.13.3 3.3.3.3 1142 0x80000034 0x1624
172.20.23.3 3.3.3.3 733 0x80000003 0x2c31
Summary Link States (Area 0.0.0.0)
Link ID ADV Router Age Seq# CkSum Route
172.20.24.0 2.2.2.2 484 0x80000003 0xd09f 172.20.24.0/24
172.20.35.0 3.3.3.3 294 0x80000003 0x3928 172.20.35.0/24ルータリンク広告とネットワークリンク広告の数が両方とも減った
その代わりに要約リンク広告が追加
