vlsm subnetting

VLSM (variable eldest son netmask) is the process of dividing the subnetThe subnet mask and IP address are the IP address of the network address (01 = = 0; 11 = = 1)In a nutshell, the IP address and subnet mask are written in binary, and the subnet mask of 1 corresponds to the portion of the IP address that is part of the networkThe portion of the subnet mask to 0 corresponds to the portion of the IP address that is the host portion.Live: The host par

certain number of English words is very important, remember.OSPF protocol is a very many dynamic routing protocol used in production environment now, so mastering the principle and configuration is very important for the students who will be engaged in the network industry.The mastery of OSPF requires understanding the entire process of OSPF, first of all the basic concepts in OSPF.OSPF is one of the internal gateway protocols, based on the link state algorithm.1 Features (why these features ar

To set RIP, you must complete the following commands. The RIP must be valid, and other tasks are optional.Make RIP validAllows update of RIP unicast messages.Apply the offset to the routing selection scaleAdjust TimerRIP versionMake RIP authentication validMake route summary invalid run IGRP and RIP in parallelMake confirmation of source IP address invalidMake horizontal segmentation valid or invalidSet inter-group latency Filter RIP InformationKey Management (available in RIP 2)

for Novell and Appletalk software ｡ ◆ Internal Gateway Protocol (IGP) ◆ IP route information protocol updates are broadcast once every 30 seconds (the multicast addresses of all RIPv2 routers are 224.0.0.9 )｡ ◆ UDP (User Datagram Protocol) Port 520 ｡ ◆ The manageable distance is 120 ｡ ◆ A single measurement criterion is the number of computing hops (the limit is 15 and the count is infinite) ◆ Timer helps adjust performance: Update timer-the frequency of Route updates ｡ The IP route information

updates to reduce bandwidth consumption)increase the network size. (RIP Max 15 hops, ERGRP 255 hops, IGRP 224 hops, other defaults are 100 hops)support three Layer network protocol. (Support IP, IPX, etc.)support for VLSM and discontinuous networks. (RIP and IGRP not supported)triggers the update. (Query Package Update routing table is sent when routing changes, using incremental update)no class routing protocol. (can be divided into subnets, the agg

as follows #ipf-L pass in quick on Lo0 all #ipf-L block in quick on em0 for 192.168.0.0/16 explanation: IPF allows access at Lo0 (loopback address)All IPF locks into the em0 from any to 192.168.0.0/16 (class B) Very simple ipnat is a tool that can do NAT forwarding under IPF, I generally write NAT rules to a file, so that when the boot time will automatically load many rules, not one to execute. Typical file content is as follows map Bce1 192.168.10.0/25, 211.103.xxx.xx1/32# forwarding Bce1 add

generally . RIP uses UDP packets to update routing information. The router Updates the routing information every 30s, and if there is no response from the neighboring router within 180s , it is considered that the route to the router is not available and the router is unreachable. If the router's answer is still not received after 240s, the routing information about the router is removed from the routing table. RIP has the following characteristics: Routers of different vendors can be connec

. After a route table is created successfully, I will "quiet" and only send the "Hello" packet to perceive the existence of the affinity Keepalive ). In short, the dynamic routing protocol can be divided into two ways based on its learning and computing routing:Distance vector protocolThe neighbor is the finished product. Only the optimal route is provided. WhileDistance vector protocolIt is a semi-finished product, giving you all the link statuses of your own, and how to choose the specific lin

(Open Shortest Path first, open Shortest Path Priority) protocol, is currently the most widely used networkOne of the broad routing protocols. belong to the internal Gateway routing protocol, can adapt to various scales of network environment, is a typical chainThe road State (link-state) protocol.The OSPF routing protocol spreads the link state information of the device to the whole network, so that each device in the net synchronizes aA database (LSDB) with a full network link state, then the

;"Experimental Equipment"Three-layer Switch 1 unitsRouter 2 unitsCrossover line or straight wire 3 strips"Experimental principle"OSPF (Open Shortest Path first, open Shortest Path Priority) protocol, is currently the most widely used networkOne of the broad routing protocols. belong to the internal Gateway routing protocol, can adapt to various scales of network environment, is a typical chainThe road State (link-state) protocol.The OSPF routing protocol spreads the link state information of the

is a private address. (192.168.0.1---192.168.255.255)Class D address(1) The Class D address does not divide the network address and the host address, its 1th byte of the first four bits fixed to 1110. (2) Class D address range: 224.0.0.1---239.255.255.254Class E Address(1) The E-class address does not divide the network address and the host address, its 1th byte of the first four bits fixed to 1111. (2) Class E address range: 240.0.0.1---255.255.255.254 IP address if you use only the ABCDE clas

Migration of routing protocols FLSM to vlsm fixed-length masks to variable-length subnet masks Route redistribution: Allow two different protocols to learn from each other to route. Using the seed metrics The metric values for various routing protocols are different, so use the seed metric value to fix the seed metric value. The default seed metrics Infinity Infinity Any protocol redistribution into RIP, metric values are infinitely large An

class C, multiple consecutive Class C addresses are used for aggregation and allocation. The adoption of CIDR technology has slowed the growth of Internet route tables in recent years. ◆ Dial-up access: when a user performs dial-up access, the user dynamically allocates an IP address on demand using the Point-to-Point Protocol (PPP) and Dynamic Host Configuration Protocol (DHCP) to achieve address reuse. ◆ Variable-length Subnet Mask (VLSM): an enter

parameter named subnet mask specifies how many bits in the address are used for subnet identification and how many bits are reserved as the actual host identity. Classless Internet Domain Routing (CIDR)-- CIDR does not need to use the address classification system to flexibly divide the address space. It uses a CIDR prefix (also called a variable-length subnet mask VLSM) the number of bits in the specified address as the network identifier. One of th

It is very useful to know some knowledge about OSPF router protocols. Many people may not know the commands commonly used in OSPF router protocols and the explanations of some terms. It does not matter. After reading this article, you will certainly have a lot of GAINS, I hope this article will teach you more things. Advantages of the OSPF Router Protocol: ① Rapid response to network changes; ② Send triggered updates when the network changes; ③ Supports the