CCNA Learning Notes 6--routing principle, static routing

Routers work on the third tier, providing a device that forwards IP packet functionality

Commonly referred to as routing information

Routing information is a piece of information that goes to the destination, indicating the direction of the destination.

In addition, a route can represent a path. Refers to the router after receiving the IP packet, to find their own routing information to forward the process.

Routing table: Where to store routing information

IP packet forwarding is implemented according to the routing table.

A route entry contains the information:

Prefix

Mask

Scare Jump/Out interface

Manage Distance AD

Measure value

The principle of Router forwarding IP packets:

There is a matching route entry on the forward, no drop

Follow the longest matching rule when matching multiple lines

Route table Generation in 3 ways:

Direct Connect Routing

Static routes

Dynamic routing

Configuration: IP route + target segment and mask + Next hop interface address (or local out interface)

Static routes are configured on both ends (direct-attached routers are not needed)

Routing back and forth within the network needs to be consistent, but it doesn't matter whether the Internet is consistent

is a no-connect service, after forwarding it no longer tube

Summarize static routes

Pros: Reduce routing table size

Reduce CPU, memory overhead

More flexibility when addressing the network

192.16.12.0/24

192.16.13.0/24

192.16.14.0/24

192.16.15.0/24

192.16.0000 1100.0

192.16.0000 1101.0

192.16.0000 1110.0

192.16.0000 1111.0

Prefix same as copy, different position 0:192.16.12.0

Mask to same bit:/22

Default route: IP route 0.0.0.0 0.0.0.0 + next-Hop interface address (or local out-of-interface)

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Configure the normal static need to configure 18 to the entire network interoperability

R1:ip Route 23.1.1.0 255.255.255.0 12.1.1.2

IP Route 3.1.1.1 255.255.255.255 12.1.1.2

IP Route 24.1.1.0 255.255.255.0 12.1.1.2

IP Route 4.1.1.1 255.255.255.255 12.1.1.2

IP Route 2.1.1.1 255.255.255.255 12.1.1.2

Similarly R3 R4 is also 5

R2:ip Route 1.1.1.1 255.255.255.255 12.1.1.1

IP Route 3.1.1.1 255.255.255.255 23.1.1.3

IP Route 4.1.1.1 255.255.255.255 24.1.1.4

Configure default only 6

R1 R3 R4 Write an IP route 0.0.0.0 0.0.0.0 point to R2

R2 Write 3 to 1.1.1.1 3.1.1.1 4.1.1.1

Floating static routes

Floating static routes are not permanently saved in the routing table, and they load the backup route only if a preferred route match fails

Use administrative distance to control ad smaller priority static route ad defaults to 1

Load Balancing

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equivalence R1 IP route 4.1.1.1 255.255.255.255 14.1.1.4

IP Route 4.1.1.1 255.255.255.255 12.1.1.2

Test the target router debug IP packet; The source router no IP cef(the load under CEF is based on the stream load, that is, the same source goes to the same path for the same purpose only, and the process-based forwarding after the CEF is closed, that is, one package goes one path, the second one goes another path)

Ping a package ping 4.1.1.1 repeat 1

Non-equivalence (EIGRP) path distribution is inversely proportional to the traffic and routing costs

Recursive table Query

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CCNA Learning Notes 6--routing principle, static routing