Two models of OSPF planning: double tower Raider and dog tooth crisscross

Hello everyone , What I bring to you today is OSPF Planning two models ： Twin towers 、 be zigzag , Let's go straight to ！

OSPF Planning Twin Towers

explain ：

OSPF If there are two in a certain area ABR, And in two ABR It's all right area n The routing within Aggregation operation .

The best configuration ：

• Two sets of ABR The red line between should use Ethernet sub interface technology , A sub interface belongs to area0, The other belongs to area n; Or the link is planned as area n, Configure virtual connections at the same time ;
• ABR Of loopback0 Planning in area 0

OSPF Planning is intertwined

explain ：

Sometimes the devices in the access layer will be Disorder To connect with the aggregation layer ,OSPF How to divide the area ？

• If all convergence layers and access layers are divided into one area , It will be too big .
• If two convergence layer devices are selected, plus all access layer devices connected to them at the same time, they are divided into one area Too many areas will result , And there are no rules , And right IP Address planning is very unfavorable .
• It is recommended that all link interfaces connected to each aggregation layer device be divided into one area .

that , In this way, for the access layer equipment, the two uplink links belong to area1 and and area2 , So it's loopback Which region does the interface and business interface belong to ？

The best configuration ：

Loopback Interfaces and business interfaces cannot be classified into any area Area , Otherwise, when an uplink is interrupted , It will make other devices inaccessible loopback Address or business segment , Must pass import Command to type5 Class routing is published .