A class with no class routing under the matching principle route
Use of class routing: router first major network number match, if the primary network number exists, it continues to match the subnet number, and do not take into account the default route, if the subnet can not match, discard the packet (in the classification of routing, the router that knows all under all the main network subnet), and use the ICMP unreachable return a response. If the primary network number does not exist, use the default route (default route exists premise).
The situation in some earlier versions of IOS (12.0 the previous version), these earlier versions the default is not open ip classless.
After opening ip classless routing behavior will change the router, the router will be the longest time the most exact match or match the default route
Use of non-class routing, if not to find the most specific match, use the default route.
ip classless command is to change the main function of a class of routing protocol behavior of the routing table lookup.
Example 1: A router running the routing protocol to RIP (a class of routing protocols), routing table as follows:
R 10.1.0.0/16 via 1.1.1.1
R 10.2.0.0/26 via 1.1.1.2
R * 0.0.0.0 / 0 via 1.1.1.3
Now suppose there are three IP packets, packet A goal of IP is 10.1.1.1, target IP packet B is 10.3.1.1, the packet target IP is 11.11.1.1 C
A class of routing protocol behavior of the routing table lookup is as follows:
First find where the main objective of IP network routing table if there is any one of the main network subnet from the case, which must exactly match the subnet by the; If there is no exact match found by the sub-network, it will not select the last default route, but dropped packets. If the routing table does not exist in any one of the main network by a subnet, then chose the default route.
Message A: target IP as 10.1.1.1, where the main network 10.0.0.0, currently exist in the routing table from the 10.0.0.0 subnet, then the router to find the subnet by a further, whether the exact match, we???10.1.0.0/16????????????????????????A?????????????????br />
??????B?????P??0.3.1.1????????????10.0.0.0???????????????10.0.0.0?????????????????????????????????????????????????????????????????????10.1.0.0/16??0.2.0.0/16??????????????????????????????????????????????????????????????????????br />
??????C?????P??1.1.1.1????????????11.0.0.0?????????????????1.0.0.0???????????????????????????????????????????????????C????????br />
??????????????????????????????????????p classless?????????????????????????????????????????????????????????????????????B???????????????????????br />
??????????????????????????????????????????????????????????????????????????????
????:
COREL KNOCKOUT matting examples Guide (4)
Why Such A Dramatic Programming In Chinese?
Vigilance “Li Cheng Ru-style” risk
Close Contact With ASP.Net (3) Asp + In The Control
AMD: It is easy to say the REALITY is cruel
C + + Compiler On The Template Of Separate Answers To Questions
Levels Adjustment Channel To Marry
