Ospf multizone
Tips:
belonging to a region identical router ospf database;
each router interface corresponds with a link information, a routing area of 10 three state UP interface 10 have link state information (LSA) ;
border region on each route; Isis is on the link;
Regional planning benefits
1, saving equipment resources
2, to enhance equipment reliability, safety; the latter part of maintenance
3, enhanced network scalability, rapid convergence
Three communication amount Ospf
1, the traffic domain (the traffic Intra-Area)
2, inter-domain traffic (the traffic Inter-Area)
. 3, the external traffic (external traffic)
ABR: area border router area border router
functions: enable communication between different regions
defined: simultaneously connected to the backbone region and a non-backbone area
Configuration:
configure port area and links on each route ospf added
on the border: links are declared for each port in the region corresponding
changes to the link ospf link state: in the interface Mode: ospf link-type {value}
verification neighbor and routing tables
verifying
the real network address corresponding to the port is not reflected in the routing entries of some - type of network
Huawei apparatus, the line distance ospf (by the preference) 10; metric cost (cost )
Display OSPF routing
verification ASE type of routing - the drawn embodiment Router Advertisement: network / import-router
Tips: Router Advertisement way
Route Network are: intral internal (Intra-Area | Inter-Area)
Import-route redistribution (cisco: redistribution): external outside 
Ospf external type: 1/2 (NSSA / ASE)
Ospf general area: 
backbone area: area0
non-backbone area: area0 and connected to
the database: there LSA - link state advertisement (link state advertisement)
each router has created each interface, and the interface corresponding adjacent contacts database velocity component
common LSA there are six types of 
special areas
reference: https://wenku.baidu.com/view/bad0e58c250c844769eae009581b6bd97e19bc44.html
----- means that do not allow the presence of 5 LSA area;
as rerouting there is distributed, there are security problems, so they need special regional
category: inside was reflected in the data package options, all links within the same region should be set as
Stub area: Stub area; (backbone area can not be configured as a special area ) after turning on the router will automatically generate a default route (default route to both the backbone) and belonging to the inter-area OSPF
area does not exist 4,5-LSA 
configuration commands: OSPF. 1 - area34 - Stub
Display view OSPF LSDB database information
totally stub area: totally stubby area (upgraded) without the presence of LAS class 5 There are three categories, four
in the specific area stub ABR do: stub no summary (leaving only the default route)
may reduce the size of the database to obtain the stub area;
can also reduce the instability in other regions, resulting in the region adverse effects
Nssa area: Stub Area SO not
the Totally nssa area: the area is completely nssa
Tips:
In any router ospf domain can import external routes are called ASBR (intelligent routing system boundary)
LSA type:
1 Class: - router lsa: any ospf router will generate a class corresponding to an LSA describes routers themselves have any particular region in a region
2 categories: -
Class 3 --summary network: ABR will produce only role is to pass the time between the different regions of routers; 3 LSA calculated based routing, we call inter-area routes.
Generating class 3 LSA:
ABR will have a non-routing in the backbone area, formed into 3 LSA transmitted to the backbone region
3 LSA in the backbone area ABR will have received in area 0, continue to send the next other non-backbone area;
the ABR region may also be obtained route 0, 3 LSA into the form, the non-transmission regions backbone
category 3 LSA during transmission, each of the ABR had a "advertised route" will change once
the class 4 LSA--
is obtained ABR ASBR generated in the same area; transmission, with 3 LSA Similarly, ABR each had a "router advertisement will change
class 5 LSA - as external lsa
only ASBR can produce, effect is a routing, it can be transmitted to anywhere in the OSPF network. and in the transmission process, the LSA will not produce any changes.
NSSA: no so stub area
incomplete distal region: the region does not allow the LSA class 4/5, but is allowed external routes,
the outer region route based expression --7 LSA (present only in the region)
the NSSA region to other regions will have a one-way conversion 7--5
Tips: if two or more routers as ABR NSSA, then select the large rOUTER-ID as a main conversion routing
configurations: and stub as
Totally NSSA
compared with the NSSA, is less routing LSA represents the detail of three types; i.e., only class 1 class 2 class 7 LSA; a 7 class default route LSA represents only automatically generated by an NSSA obtained ABR, can realize NSSA go with the other regions and exchange external routing
configuration commands and totally stub as
in all ABR NSSA areas do on it: nssa no-summary in the area where