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ccna certification online free.00d0.ba97.dl01 FFFF.FFFF.FFFF 0x08065 After Serverl receives the ARP request from Router R2, it updates its own ARP table, at which point Serverl's ARP tableThe ARP table of Serverl is as follows: C:\>arp -a Internet Address 172.16.2.2 Physical Address 00d0.ba97.dl01 Type dynamic Serverl receives an ARP request from Router R2 and replies with a unicast ARP reply packet with the following address information. Source MAC address Destination MAC address Type 0060.702B.C127 00d0.ba97.dl01 0x0806 After router R2 receives the ARP reply from Serverl, it updates its own ARP table. At this time, router R2 can re-encapsulate the packet (layer 2 rewrite) and then forward the packet to server Serverl,the address information is as follows: Source MAC address Destination MAC address Type Source IP address Destination IP address Protocol 00d0.ba97.dl01 0060.702B.C127 0x0800 172.16.1.100 172.16.2.100 0x01 After router R2 receives the packet, it continues to perform a process similar to the one described above, and the packet finally reaches PC1, completing the process of a ping. The above process shows that the Layer 2 address information will be rewritten during the whole packet delivery process from PC1 to Serverl, but the Layer 3 IP address information remains unchanged. Chapter 5 Static Routing The main function of a router is to determine the best path to send packets and to transport them from one network to another. Routing is at the heart of all data networks, and it delivers packets from source to destination by searching for routing information stored in the routing table, so the routing table is at the heart of the router's work. There are usually three ways that routers build routing tables: direct routing, static routing, and dynamic routing protocols. Static routing populates the routing table by manually configuring routing information by the network administrator. In many cases, dynamic routing protocols are used in conjunction with static routing. This chapter describes the characteristics, uses, classification, and configuration of static routes. 5.1 Static Routing Overview 5.1.1 Static Routing Features When a router forwards a packet, it has to look up the corresponding routing entry and its corresponding outgoing interface in the routing table before it knows which interface the packet should be forwarded out of. As the simplest way to construct a routing table, the advantages, disadvantages, and use cases of static routing are described below. 1. Uses of Static Routing In small networks that do not grow significantly, the use of static routes facilitates the maintenance of routing tables. In this case, using dynamic routing protocols may add an additional administrative burden. Routing to end-node networks. An end-node network is a network that can only be accessed by a single route, so the router has only one neighbor, so there is no need to use a dynamic routing protocol between this link. Use a single default route. If a network cannot find a better matching route entry in the routing table, the default route can be used as the path to that network. 2. Advantages of Static Routing Takes up less CPU and memory resources. Highly controllable and also easy for administrators to understand the entire network routing information. No dynamic updating of routes is required, which reduces bandwidth consumption and improves network security. Simple and easy to configure. 3. Disadvantages of Static Routing Initial configuration and maintenance is time consuming for administrators. Configuration is error-prone, especially for large networks. When the network topology changes. requiring administrators to manually maintain the changed routing information. .60.Cisco Networking Lab CCNA Lab Guide (Release 2) Maintenance becomes increasingly cumbersome as the network grows in size and configuration. It requires an administrator to have a complete understanding of the entire network before proper operation and configuration can be performed. 5.1.2 Default Routes The default route is the route that the router will finally use in the routing table when it cannot find an explicit or summary route to the destination network, and the default route matches all packets. A default route is often configured on edge routers connected to ISP networks. Note that whether the router uses the default route to forward packets also depends on whether classless routing behavior ( IPClassless) is turned on. 5.1.3 Static Route Classification Static routes are most commonly used to connect to a specific network or to provide a gateway of last resort for end-of-route networks. A network that has only one exit is called a StubNetwork. o Static route types are described below. Standard static route: A static route used to connect to a specific remote network. Default static route: is a static route with 0.0.0.0/0 as the destination IPv4 address or ::/0 as the destination IPv6 address Routing. Note that the explicit route takes precedence over the default route. Summarized static routes: To save memory space, protect the internal network effectively, and improve routing table lookup efficiency, multiple static routes can be summarized into a single static route to reduce the number of routing table entries. Floating static route: A static route that provides a backup path for the primary static route or dynamic route. Floating static routes are only used when the primary route is not available. This is achieved by configuring the administrative distance of the floating static route to be greater than the administrative distance of the primary route. 5.2 Configuring Static Routes 5.2.1 Experiment 1: Configuring IPv4 Static Routes 1. Experiment Purpose This experiment enables you to learn how to configure an IPv4 static route with a next-hop address. The method of configuring IPv4 static route with outgoing interface. Configure a summary IPv4 static route. How to configure a floating IPv4 static route. The role of proxy ARP. The meaning of routing tables. How to use the extended ping command. 2. Experimental Topology The experimental topology for configuring IPv4 static routes is shown in Figure 5-1. Chapter 5 Static Routing .61 . B 172.16.0.100 172.16.4.100 172.16.0.0/24 17216.12.0/24 172.16.23.0/24 172.16.34.0/24 172.16.4.0/24 G0/1 swm S0/0/0 G0/0 G0/0 g0/2 172.16.1.0/24 17216.21.0/24 2/16.1.100Figure 5-1 Experimental Topology for Configuring IPv4 Static Routes(1) Configure router R1(config)#interface GigabitEthernetO/O Rl(config-if)#ip address 172.16.21.1 255.255.255.0 Rl(config-i0#no shutdown R1 (coniig-if)#exit R1 ( config)#interface GigabitEthernetO/1 Rl(config-if)#ip address 172.10.1 255.255.255.0 Rl(config-if)#no shutdown Rl(config-if)#exit R1 (config )#interface GigabitEthernetO/2 Rl(config-if)#ip address 172.16.1.1 255.255.255.0 Rl(config-if)#no shutdown Rl(config-if)#exit R1 (config)# interface Serial0/0/0 Rl(config-if)#ip address 172.1642.1 255.255.255.0 Rl(config-if)#no shutdown Rl(config-if)#exit Rl(config)#ip route 0.0. 0.0.0 0.0.0.0 SerialO/O/O 100 Configure a static default route with a send-out interface, and set the administrative distance to 100, the default is 1. Since the serial link rate is much slower than Ethernet, this route is used as a backup route, that is, a floating static routeRl(config)#ip route 0.0.0.0 0.0.0.0 172.16.21.2 Configure a static default route with the next-hop address, which is used as the primary route