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http://xuanbo.blog.51cto.com/499334/200620

区域内前缀LSA（Intra-Area-Prefix-LSA）

该类型LSA在本区域内传播，具有以下两种功能之一：通过参考网络LSA把IPv6地址前缀与转递网络（transit network）相关联；或者通过参考路由器LSA把IPv6地址前缀与路由器相关联。一台路由器可以为给定的区域产生多个该类型的LSA，这些LSA使用链路状态ID字段（Link State ID）区分。DR为它所代表的链路产生一个或多个该类型的LSA，向整个区域内通告该链路的地址前缀。

Intra Area Prefix LSA描述了Router LSA和Network LSA所携带的路由信息，因此在Intra Area Prefix LSA中需要标明该LSA引用的Router LSA或Network LSA，这是通过Referenced LS Type、Referenced Link State ID和Referenced AdvertisingRouter字段来联合标识的。

主要字段的解释如下：

? # Prefixes：包含的IPv6 地址前缀的个数。

? Referenced LS Type：引用LSA 的类型，取值为1 表明该LSA 与RouterLSA 相关，取值为2 表明该LSA 与Network LSA 相关。

? Referenced Link State ID：引用LSA 的Link State ID。如果引用的是Router LSA，此字段值为0；如果引用的是Network LSA，此字段值为DR在该条链路上的Interface ID。

? Referenced Advertising Router：引用LSA 的发布路由器。如果引用的是Router LSA，此字段值为产生该LSA 路由器的Router ID；如果引用的是Network LSA，此字段值为DR 的Router ID。

如下图所示：

3.1.3 OSPFv3路由协议工作机制

OSPFv3协议的工作原理与OSPFv2的工作原理是一样的，因为OSPFv3是在OSPFv2的基础之上修改而成的。在路由器上可以使用show ipv6 ospf adj来了解其邻居、邻接之间形成的工作过程，如下所示：

R1#debug ipv6 ospf adj

OSPFv3 adjacency events debugging is on

R1#clear ipv6 ospf process

Reset ALL OSPF processes? [no]: yes

R1#

*Sep 5 11:56:57.747: OSPFv3: Interface Loopback0 going Down

*Sep 5 11:56:57.747: OSPFv3: Interface Ethernet1/0 going Down

*Sep 5 11:56:57.747: OSPFv3: Neighbor change Event on interface Ethernet1/0

*Sep 5 11:56:57.751: OSPFv3: DR/BDR election on Ethernet1/0

*Sep 5 11:56:57.751: OSPFv3: Elect BDR 0.0.0.0

*Sep 5 11:56:57.751: OSPFv3: Elect DR 2.2.2.2

*Sep 5 11:56:57.751: OSPFv3: Elect BDR 0.0.0.0

*Sep 5 11:56:57.751: OSPFv3: Elect DR 2.2.2.2

*Sep 5 11:56:57.751: DR: 2.2.2.2 (Id) BDR: none

*Sep 5 11:56:57.755: OSPFv3: 2.2.2.2 address FE80::C800:4CFF:FE18:1C on Ethernet1/0 is dead, state DOWN

*Sep 5 11:56:57.755: %OSPFv3-5-ADJCHG: Process 10, Nbr 2.2.2.2 on Ethernet1/0 from FULL to DOWN, Neighbor Down: Interface down or detached

*Sep 5 11:56:57.759: OSPFv3: Neighbor change Event on interface Ethernet1/0

*Sep 5 11:56:57.759: OSPFv3: DR/BDR election on Ethernet1/0

*Sep 5 11:56:57.759: OSPFv3: Elect BDR 0.0.0.0

*Sep 5 11:56:57.763: OSPFv3: Elect DR 0.0.0.0

*Sep 5 11:56:57.763: DR: none BDR: none

*Sep 5 11:56:57.763: OSPFv3: Remember old DR 2.2.2.2 (id)

*Sep 5 11:56:57.767: OSPFv3: Interface Loopback0 going Up

*Sep 5 11:56:57.767: OSPFv3: Interface Ethernet1/0 going Up

*Sep 5 11:56:57.787: OSPFv3: 2 Way Communication to 2.2.2.2 on Ethernet1/0, state 2WAY

*Sep 5 11:56:57.787: OSPFv3: Backup seen Event before WAIT timer on Ethernet1/0

*Sep 5 11:56:57.791: OSPFv3: DR/BDR election on Ethernet1/0

*Sep 5 11:56:57.791: OSPFv3: Elect BDR 1.1.1.1

*Sep 5 11:56:57.791: OSPFv3: Elect DR 2.2.2.2

*Sep 5 11:56:57.791: OSPFv3: Elect BDR 1.1.1.1

*Sep 5 11:56:57.791: OSPFv3: Elect DR 2.2.2.2

*Sep 5 11:56:57.795: DR: 2.2.2.2 (Id) BDR: 1.1.1.1 (Id)

*Sep 5 11:56:57.795: OSPFv3: Send DBD to 2.2.2.2 on Ethernet1/0 seq 0x13E3 opt 0x0013 flag 0x7 len 28

*Sep 5 11:56:57.855: OSPFv3: Rcv DBD from 2.2.2.2 on Ethernet1/0 seq 0xA36 opt 0x0013 flag 0x7 len 28 mtu 1500 state EXSTART

*Sep 5 11:56:57.859: OSPFv3: NBR Negotiation Done. We are the SLAVE

*Sep 5 11:56:57.859: OSPFv3: Send DBD to 2.2.2.2 on Ethernet1/0 seq 0xA36 opt 0x0013 flag 0x0 len 28

*Sep 5 11:56:57.879: OSPFv3: Rcv DBD from 2.2.2.2 on Ethernet1/0 seq 0xA37 opt 0x0013 flag 0x3 len 188 mtu 1500 state EXCHANGE

*Sep 5 11:56:57.883: OSPFv3: Send DBD to 2.2.2.2 on Ethernet1/0 seq 0xA37 opt 0x0013 flag 0x0 len 28

*Sep 5 11:56:57.883: OSPFv3: Database request to 2.2.2.2

*Sep 5 11:56:57.887: OSPFv3: sent LS REQ packet to FE80::C800:4CFF:FE18:1C, length 96

*Sep 5 11:56:58.131: OSPFv3: Rcv DBD from 2.2.2.2 on Ethernet1/0 seq 0xA38 opt 0x0013 flag 0x1 len 28 mtu 1500 state EXCHANGE

*Sep 5 11:56:58.131: OSPFv3: Exchange Done with 2.2.2.2 on Ethernet1/0

*Sep 5 11:56:58.131: OSPFv3: Send DBD to 2.2.2.2 on Ethernet1/0 seq 0xA38 opt 0x0013 flag 0x0 len 28

*Sep 5 11:56:58.139: OSPFv3: Synchronized with 2.2.2.2 on Ethernet1/0, state FULL

*Sep 5 11:56:58.139: %OSPFv3-5-ADJCHG: Process 10, Nbr 2.2.2.2 on Ethernet1/0 from LOADING to FULL, Loading Done

*Sep 5 11:57:00.691: OSPFv3: Neighbor change Event on interface Ethernet1/0

*Sep 5 11:57:00.691: OSPFv3: DR/BDR election on Ethernet1/0

*Sep 5 11:57:00.691: OSPFv3: Elect BDR 1.1.1.1

*Sep 5 11:57:00.695: OSPFv3: Elect DR 2.2.2.2

*Sep 5 11:57:00.695: DR: 2.2.2.2 (Id) BDR: 1.1.1.1 (Id)

3.1.3 OSPFv3多区域配置

在配置OSPFv3路由协议之前，需要注意到以下几点：

? 接口要参与OSPFv3运行，必须在接口配置模式下明确启动。而在OSPFv2中，这是通过在OSPF路由配置模式下，通过network命令间接启动。

? 如果配置接口参与OSPFv3运行，那么接口上所有的地址都将参与IPv6运行。而在OSPFv2中，所有地址都必须通过network命令启动。

? 在运行OSPFv3的环境中，在同一个链路上能够允许运行多个OSPF实体，该链路所连的不同设备可以选择参与运行某一个OSPF实体。OSPFv2并不支持该功能。

? 每台运行OSPFv3进程的设备都必须使用一个router ID来标识，router ID使用IPv4地址格式。不同于OSPFv2，OSPFv2进程将自动获取IPv4地址作为router ID，设备在启动OSPFv3进程后，用户必须使用router-id命令为OSPFv3进程配置router ID，否则OSPFv3进程将无法启动。

本实验的网络拓扑如下图所示：

具体配置如下所示：

路由器R1配置

ipv6 unicast-routing

!

interface Loopback0

no ip address

ipv6 address 2001:10::1/64

ipv6 ospf 10 area 10

!

interface Ethernet1/0

no ip address

duplex full

ipv6 address 2001:1::1/64

ipv6 enable

ipv6 ospf 10 area 10

!

interface Ethernet1/1

no ip address

duplex full

ipv6 address 2001:5::1/64

ipv6 enable

!

ipv6 router ospf 10

router-id 1.1.1.1

log-adjacency-changes

路由器R2配置

ipv6 unicast-routing

!

interface Ethernet1/0

no ip address

duplex full

ipv6 address 2001:1::2/64

ipv6 enable

ipv6 ospf 10 area 10

!

interface Ethernet1/1

no ip address

duplex full

ipv6 address 2001:2::1/64

ipv6 enable

ipv6 ospf 10 area 0

!

ipv6 router ospf 10

router-id 2.2.2.2

log-adjacency-changes

!

路由器R3配置

ipv6 unicast-routing

!

interface Ethernet1/0

no ip address

duplex full

ipv6 address 2001:2::2/64

ipv6 enable

ipv6 ospf 10 area 0

!

interface Ethernet1/1

no ip address

duplex full

ipv6 address 2001:3::1/64

ipv6 enable

ipv6 ospf 10 area 20

!

ipv6 router ospf 10

router-id 3.3.3.3

log-adjacency-changes

路收器R4配置

ipv6 unicast-routing

!

interface Loopback0

no ip address

ipv6 address 2001:11::1/64

ipv6 ospf 10 area 20

!

interface Ethernet1/0

no ip address

duplex full

ipv6 address 2001:3::2/64

ipv6 enable

ipv6 ospf 10 area 20

!

interface Ethernet1/1

no ip address

duplex full

ipv6 address 2001:4::1/64

ipv6 enable

ipv6 ospf 10 area 20

!

ipv6 router ospf 10

router-id 4.4.4.4

log-adjacency-changes

可以使用show命令来查看路由表和邻居状态。

R1#sh ipv6 route

IPv6 Routing Table - 11 entries

Codes: C - Connected, L - Local, S - Static, R - RIP, B - BGP

U - Per-user Static route

I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary

O - OSPF intra, OI - OSPF inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2

ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2

C 2001:1::/64 [0/0]

via ::, Ethernet1/0

L 2001:1::1/128 [0/0]

via ::, Ethernet1/0

OI 2001:2::/64 [110/20]

via FE80::C800:4CFF:FE18:1C, Ethernet1/0

OI 2001:3::/64 [110/30]

via FE80::C800:4CFF:FE18:1C, Ethernet1/0

OI 2001:4::/64 [110/30]

via FE80::C800:4CFF:FE18:1C, Ethernet1/0

C 2001:5::/64 [0/0]

via ::, Ethernet1/1

L 2001:5::1/128 [0/0]

via ::, Ethernet1/1

C 2001:10::/64 [0/0]

via ::, Loopback0

L 2001:10::1/128 [0/0]

via ::, Loopback0

L FE80::/10 [0/0]

via ::, Null0

L FF00::/8 [0/0]

via ::, Null0

R3#sh ipv6 ospf neighbor

Neighbor ID Pri State Dead Time Interface ID Interface

2.2.2.2 1 FULL/DR 00:00:35 6 Ethernet1/0

4.4.4.4 1 FULL/DR 00:00:33 6 Ethernet1/1