3.CCNA, CCNP configuration OSPF study notes summary
Route Source Default Distance
Connected interface 0
Static route 1
External BGP 20
Internal Enhanced IGRP 90
IS‐ IS 115
External Enhanced IGRP 170
Internal BGP 200
Unknown;Discard Route 255
Lesson 13 Static Routing
Ensure that each router along the path hasa route to the destination (two-way)
Summary: Use a more coarse summary routeinstead of some refinement routes, by changing the network number and subnetmask of the target network.
Conditions of use: There are common networknumbers and common exports. Advantages: Reduce routing entries and increasesearch speed
Disadvantages: may lead to sub-optimalpaths, and even loops, address planning: start is even, end is odd, preferably2n subnets and continuous allocation
Default route: 0.0.0.0 0.0.0.0
Floating static route: Conditions formaintaining the route:
The next hop must be reachable or the localexit is useful!
The main link goes down, the main routedisappears, and the backup route starts automatically!
The same target network number is the same,the subnet mask is the same, and multiple paths are compared.
AD and metric, choose the best path. ,,load balancing: A single device can not carry traffic pressure on a singlelink.
Load balancing: Layer 2: Ethernet channel,PPP MultiLink
Three layers: routing, four layers:
With multiple paths to the same target intothe routing table, it is possible to use these paths to forward data.