200-301 pdf

200-301 pdf.The host and its default router should agree on the address range of the subnet. Sometimes, people skip this check step and ignore the mask on the host or router, figuring that the mask on one device must be the same as the one on the other. However, if the router and the host have different subnet mask values, then they will also calculate different subnet address ranges, and thus the problem arises.Let's look at such an example, with the network structure shown in Figure 5-3. The IP address/mask of host A is 10.1.1.9/24, and the default router is 10.1.1.150. After a quick calculation, 10.1.1.150 - the default router address one is placed on host A's subnet, right? The default router is 10.1.1.150. The subnet calculated by host A is subnet ID 10.1.1.0, address range is 10.1.1.1 to 10.1.1.254, subnet broadcast address is 10.1.1.255.Figure 5-3 From Host TowardNetwork, the subnet calculator that matches the wrong subnet seems to work fine In this example, the host route works fine for packets whose destination address is outside the subnet. But conversely, the host cannot be reached from other locations on the network. A quick examination of the configuration of router R1 reveals the IP address/mask shown in Figure 5-3, which yields a connected route for subnet 10 ? 1.128/25, as shown in Example 5-1. Example 5-1 R1 IP address, mask and ignore the subnet of the connection of the address of host ARl# show running-config interface g0/0 Building configuration...Current configuration : 185 bytes I interface GigabitEthernet0/0 description LAN atSite 1 mac-address0200.0101.0101ipaddress 10.1.1.150255.255.255.128 iphelper-address 10.1.2.130 duplex auto speedauto108 Chapter 4, Part 1 IPv4 Routing Troubleshooting Example 5-1 (continued)! Legend omitted for brevity10.0.0.0/8is variably subnetted, 9 subnets, 4 masks C10.1.1.128/25is directly connected, GigabitEthernet0/0 L