Routing redistribution Principle

There are many network protocols, such as isis, rip, ospf, and bgp. In large companies, network devices often run multiple network protocols, if no configuration is required between various network protocols, no information can be exchanged between devices. In this case, the routing redistribution technology appears, the purpose of Route redistribution is to achieve collaboration among multiple routing protocols. Routing redistribution principle: by adding certain configurations to the configuration of various routing protocols, the routing protocol is broadcast to another routing protocol, this allows each routing protocol to detect the network segments of other routing protocols to transmit data. The redistribute command rip protocol redistribute command redistribute protocol [metric-value] [match internal | external nssa-external type] [route-map-tag] protocol: source Routing Protocol metric-value for Route redistribution: Set the metric value of Route redistribution (1 · 6 ), the metric value set using the default-metric command is not match internal | external nssa-external type: set the condition for redistribution routing, only the source routing protocol suitable for redistribution is the redistribute command redistribute protocol of ospf route-map-tag application routing Diagram for redistribution.] [Metric-value] [metric-type {1 | 2}] [tag-value] [route-map-tag] protocol: source Route Protocol subnets for Route redistribution: Set whether to re-distribute subnet metric-value: Set the metric value of Route redistribution (1 · 16777214 ), the metric value metric-type that will not be set using the default-metric command: sets the routing metric type for redistribution. The default value is 2 tag-value: set the tag (0 · 2147483647) of the redistributing route to 0 by default, in addition to direct connections and default routes, the default metric value of other reseller routes is 20, the default metric value type is 2, and the default metric value is not redistribution subnet. Redistribute protocol [metric-value] of the redistribute command of the MongoDB protocol: bandwidth delay reliability load mtu parameter value is relatively complex because of the complexity of the measurement of the network, therefore, you must specify the bandwidth, latency, reliability, load, and MTU parameters for redistribution. The redistribute command redistribute protocol [metric-value] [match internal | external nssa-external type] [route-map-tag] of the isis protocol is basically the same as that of rip, during the redistribution of the isis protocol, local interfaces using the isis Protocol are not redistributed. This port must be redistributed using the direct network segment. Otherwise, local network may be inaccessible. Example: (1) re-distributing ospf, direct routing, default routing, Static Routing, and ospf to rip [plain] router rip redistribute ospf metric 2 [plain] router rip redistribute conneconneted // re-distributing the direct connection routing, the default measurement value is 1 [plain] router rip redistribute static // resend the static route, the default measurement value is 1 [plain] <pre class = "plain" name = "code"> router rip default-information originate // resend the default route, routing charts are not used for redistribution control, add "no" to disable the default route for redistribution or delete its associated route-map </pre> <pre class = "plain" name = "code"> <pre class = "plain ""name =" co De "> router rip redistribute VPN 1 </pre> (2) redistributes rip, Direct Connect route, default route, static route, isis, and VPN to ospf. <pre> </pre> <pre class = "plain" name = "code"> router ospf 1 redistribute rip subnets metric 50 </pre> <pre class = "plain" name = "code"> router ospf 1 redistribute connected subnets // The default measurement value is 20 </pre> <pre class = "plain" name = "code"> router ospf 1 redistribute static subnets // The default measurement value is 20 </pre> <pre class = "plain" name = "code"> router Ospf 1 default-information originate // default-information originate [always] [metric-value] [metric-type-value] // [route-map-name] always indicates that the default route is always advertised, whether or not the route exists, the default measurement value is 10 </pre> <pre class = "plain" name = "code"> <pre class = "plain" name = "code"> router ospf 1 redistribute isis level-2 metric 50 subnets // re-distributing isis to ospf </pre> (3) re-distributing rip and osp to isis <pre> </pre> <pre class = "plain" name = "code"> route R isis redistribute ospf 1 metric 20 // rip is the same as ospf </pre> <p> (4) re-distributing rip to ospf <br> router VPN 1 redistribute rip metric 1000 100 255 1 1500 </p> <p> when selecting a Routing Protocol in route redistribution, in addition to metric values and metric types, management distance also defines the default Management Distance for some common routing protocols in the vro. Sometimes, the default Management Distance cannot meet people's needs, at this time, we need to manually change the Management Distance of the routing protocol, the required code is distance weight {ip-address | wildcard | [access-list-number]}. Here, weight refers to the distance between 1 and 25, manage routes with a distance of 255. the discarded ip address is the ip address of the route source. ospf requires the ip address to be the router label. Identifying wildcard indicates comparing the matching character of the route source IP address. 0 indicates comparing, 1 indicates ignoring access-list-number indicates the access control list number (1-99 ), modify the Management Distance of the routes that match the access control list. </P> <pre> </pre>