Routing is undoubtedly the core of today's networks, see vast network of information, people can Haoshouqiongjing ah, and they are all mighty hundreds of pages, so want to engage in simple point, or else really Datacom have not learned, found outdated, martial arts world, only the fast is not broken.
Static Routing
Static routing is undoubtedly the simplest and most basic.
Ip route-static ( specify static routing ) 10.1.2.0 255.255.255.0 (destination and subnet mask, you Attractions) 10.1.4.2 (default gateway is on your door). The default gateway is the door no matter where you go, you have to first step. Some, such as p2p network, you can specify the interface directly on it.
NQA * , network quality analysis
What came out for a reason. For example, you have two links, one Lord, one auxiliary, if the Lord is broken, how to make up the auxiliary first time? It is behind the main static routes to add NQA test. NQA test barrier, flew on to the roads go up. How to make static routing supplemented? Priority setting a large value, such as 100 . BFD also has this feature, known as snake oil is detected. If you want to optimize switching performance of the network, so remember to be playing all kinds bfd, bfd for everything.
RIP (Routing Information Protocol)
Basis for comparison, as long as the specified RIP version, and network router each port can be used together. There are a few stuff, a word to say.
Three timers , Update (okay 30s say hello), Age (the aging time is not updated. Routes not), garbage collection (not updated within this time, not to kill the route).
Split level , but also do not borrow money, the route is where he comes from, and not returned it.
Poison reverse , good deed goes unpunished, but also black money, cost 16 routes, nor can it gave it.
Triggered update , to live once you do, do not wait to go to work time.
These things are also common elsewhere, rip out of date, but its mechanism is not more than obsolete.
RIPng (Routing Information Protocol Next)
Used in IPv6 on the network RIP protocol, open ripng process, the interfaces are open ripng process can be.
OSPF (Open Shortest Path First)
This routing protocol can be used in large networks, so their places a little too much.
* Basic use is to first get hold of a router Router ID (usually local loop IP address on the entire network) , then the configuration process ID (like a windows process the same), domain (a region, the backbone is 0 ), the configuration of port network number, using wildcards (and RIP little different).
Shajiao wildcard? This is 10.1.2.0 0.0.0.255, and subnet mask is opposite.
* Do not know who specified, each domain must be the backbone of the domain 0 is connected, and sometimes had to use virtual connection to maintain this principle, vlink the peer- command.
* Since OSPF Fenwick, sometimes a domain only needs a default route out on the line, a man is like a dormitory to the cafeteria to buy lunch enough, it all go to waste of resources, then the field is called stub domains. ABR ( Area Router border ) is the dormitory door . Totally stub, inter-domain routing is not allowed.
* If someone girlfriend to go out to eat, then engage in NSSA domain, go outside eating packaged Type 7 lunch ( NSSA proprietary) back gate called ASBR ( AS border Router ), the dormitory door ABR can be Type 7 lunch converted to Type 5 garbage throw outside quarters (further domain, such as the backbone domain 0 ).
* Route aggregation, if the courier receipt of the parcel Shenzhen and Guangzhou, he will look polymerization, unified sent to Guangdong. Routing is the same, there ABR summary routes on it, save routing table space. Extraterritorial by AS BR summary .
* IPv6 version, enabling IPv6 , specify the port IPv6 address on it.
IS-IS
Originally, I did not like the routing protocol, and now I like to use. Master Network Entity can, it's good scalability than OSPF, it is the most common carriers of the IGP.
Network entity name with a domain name the same area, which is the first digit 49.0001 . 0000.0000.0001 .00 .
49.0001 is the domain name, 0000.0000.0001 is the system ID, and finally 00 represents the Ethernet network, as long as the master network entity, basic ISIS on the same subject.
Set the IS-the IS , first set the routing process, designated IS-Level , the name of the network entity, each port enable isis on it, Ll / L2 of the router can route the polymerization, summary routes.
Level-2 routing to be *** Level-. 1 , to optimize the inter-domain routing, L1 is preferably not.
BGP
This is the only AS routing protocol between the (autonomous). This is a neighborhood gossip protocol. When configured as long as know the neighbors ( the peer ) as well as the neighbor's AS number on the OK of the.
* RR, is reflected can be routed to a router to another router, megaphone effect.
* Local priorities and community attributes a bit confused, so borrow eNSP simulator to verify Ha, say tomorrow BGP , community attribute is used to manage the route. Such as 100: 1 .
BGP路由属性很重要，记住常用的就行，就是一句话，从哪里来（Origin），到哪里去（Next_hop），走过的路（AS_Path），会玩这三个基本无敌了。
AS间的MED、AS内的Local_Pref。
策略路由和路由策略
可以指定从某个网络到某个网络的流量重新定量，尽管已经有路由指定方向。
路由策略作用于路由，策略路由作用于数据包。