※ 引述《mikevada (Believe in dreams)》之铭言：
: 我有一个LAB网络架构如下：
: ┌–––┐ ┌───┐
: │ R1│───│ R2 │
: └───┘ └───┘
: │int 0 int 0 │
: │int 0 int 0 │
: ┌───┐ ┌───┐
: │ R3 │───│ R4 │
: └───┘int 1 └───┘
: │int 2 int 2│
: │ ┌────┐ │
: └─│ R5 │──┘
: int 2└────┘int 2
: R1、R2、R3、R4的int 0跑area 0
: R3、R5的int 2跑 area 2
: R4、R5的int 2跑 area 3
: 请问R3和R4之间是要跑area 0吗?还是要另外跑一个area 4 ?
: 请版上大大指点一下，感激不尽
不懂就回去再看一次文件
https://goo.gl/TkMQFz
Each OSPF network that is divided into different areas must follow these
rules:
A backbone area - which combines a set of independent areas into a single
domain - must exist.
Each non-backbone area must be directly connected to the backbone area
(though this connection might be a simple logical connection through a
virtual link).
The backbone area must not be partitioned - divided into smaller pieces -
under any failure conditions, such as link or router down events.
Areas are identified by an area ID. Cisco IOS® software supports area IDs
expressed in IP address format or decimal format, for example, area 0.0.0.0
is equal to area 0. If there are multiple areas in your network, you need to
name the backbone area "area 0". Since this backbone connects the areas in
your network, it must be a contiguous area. If the backbone is partitioned,
parts of the autonomous system will be unreachable, and you will need to
configure virtual links to repair the partition.
A router with interfaces in two (or more) different areas is an area border
router. An area border router is in the OSPF boundary between two areas. Both
sides of any link always belong to the same OSPF area.
后面属于进阶班, 就不贴了~