When there is no routing table inside target IP address, will forward the packet to the default routing, that is why, can't find the target IP routing tables, should not discard the packet? Why do you want to transferred to the default routing?
CodePudding user response:
The default routing is the routing entry, why can't find the target IP?" When there is no routing table inside target IP address, will forward the packet to the default routing "this sentence is wrong,
CodePudding user response:
Think about why the default routing will call the name, Then think about what is the default routing target segment, the segment represent what meaning,
CodePudding user response:
IP forwarding jump one by one, when a host or router in the IP layer need to jump down a router or host sends a data feed, it first checks the destination IP address of the datagram (D), using the value in turn published D to perform the longest prefix match algorithm: the search with the following properties of all the entries in the table: (D ^ mj)=DJ,
1. Mj is index for j forwarding entries ej mask field values, DJ is the purpose of forwarding entries ej field values,
2. This means that the destination IP address D published items with each turn of mask mj bitwise and execution, and compare the results with the same item in destination DJ,
3. If meet this property, the entry ej "match" with the destination IP address,
4. When matching, the algorithm to look at the entry of the index j, as well as how many bits in the mask Jackson is set to 1, the number of bits set to 1, the more the better matching,
5. Select the most matching entries ek (i.e., more than the most mask mk 1 entry), will be the next hop field nk as forwarding data to the next-hop IP address,
If found no matching entries in turn published, the datagram is unable to deliver, -- -- -- -- -- -- -- -- -- -- Above is the most basic principles of routing, I also for you say that, indeed, H3C is that you write on a few instructions, but the above is the basic principle, the default route is also known as the default route, the IP and subnet mask is 0, namely 0.0.0.0/0.0.0.0, IP destination address and subnet mask of the default routing 0.0.0.0 do after operation, the result is 0.0.0.0, so, the entry and all the destination IP address matches, if there is no other route entries match the destination IP address, destination IP address through this routing forwarding, since all can't find the other match the destination IP address of the final routing entries will be through the whole 0 routing entry forwarded, so the routing entry is called the default routing, also known as the default routing,
CodePudding user response:
Don't bother, the default routing target segment 0.0.0.0/0 mask is 0, the matching is so long, no matter what circumstances, will be matched to the meaning of the word "this is the default, but it is the lowest priority, as long as there are other items can match to it, don't select the default routing, but from the normal route, In addition, it has nothing to do with vendors,
