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S2989G-24TX Operation Manual

Chapter 4 Routing Protocol Related Configuration

4-10

Troubleshooting: check following errors:

 Each node of route-map should at least has one node is permit match mode. When

the route map is used in routing messages filtering, the routing messages will be

considered not pass the routing messages filtering if certain routing messages does

not pass the filtering of any nodes. When all nodes are set to deny mode, all routing

messages will not pass the filtering in this route-map.

 Items in address prefix list should at least have one item set to permit mode. The

deny mode items can be defined first to fast remove the unmatched routing

messages, however if all the items are set to deny mode, any route will not be able to

pass the filtering of this address prefix list. We can define a permit 0.0.0.0/0 le 32 item

after several deny mode items are defined so to permit all other routing messages

pass through. Only default route will be matched in less-equal 32 is not specified.

4.2

Static Route

4.2.1

Introduction to Static Route

As mentioned earlier, the static route is the manually specified path to a network or a

host. Static route is simple and consistent, and can prevent illegal route modification, and

is convenient for load balance and route backup. However, it also has its own defects.

Static route, as its name indicates, is static, it won’t modify the route automatically on

network failure, and manual configuration is required on such occasions, therefore it is not

suitable for mid and large-scale networks.

Static route is mainly used in the following two conditions: 1) in stable networks to

reduce load of route selection and routing data streams. For example, static route can be

used in route to STUB network. 2) For route backup, configure static route in the backup

line, with a lower priority than the main line.

Static route and dynamic route can coexist; layer3 switch will choose the route with

the highest priority according to the priority of routing protocols. At the same time, static

route can be introduced (redistribute) in dynamic route, and change the priority of the

static route introduced as required.

4.2.2

Introduction to Default Route

Default route is a kind of static route, which is used only when no matching route is

found. In the route table, default route in is indicated by a destination address of 0.0.0.0