200-301 passing score

200-301 passing score.If the host's settings are not missing, then the next step is to check that these values match the rest of the interconnected network. Domain Name System (DNS) server IP addresses - usually a list of at least two addresses - should match the actual DNS server addresses used in the network. The rest of the settings should be compared to the correct LAN interface on the host's default router. Figure 5-2 collects all the items that should match, followed by some explanatory notes.You can check the host IPv4 settings by following the steps shown in the numbered figure. Step 1 Check the host's list of DNS server addresses against the addresses actually used by these servers. Step 2 Check the host's default router settings against the router's LAN interface configuration, using the ip address command.1.2 Basic Content 107Step 3 Check the subnet masks of the router and the host; if they use different masks, then the subnets will not match exactly, whichwill cause some host address problems.Step 4 The host and router should be connected to the exact same subnet-one with the same subnet ID and the same range of IP addresses. Then, makethe IP addresses and masks of the router and host to calculate the subnet ID and address range to determine which subnet they are on, with thesubnet to which the output of the router ip address command gets the address/mask.If the values of the settings in the IPv4 host's configuration are missing, or if there are obvious errors, then simply checking these settings can quickly identify the root cause. For example, if you can log into the router and run a show interfacesG0/0 command, and then ask the user to issue an ipconfig/all (or similar) command that tells you the output, you can compare all of the settings in Figure 5-2.However, as useful as it is to check these host settings, some host-related problems won't be as easy to spot. The next few topics will present several problems with examples that illustrate the symptoms of some of the less obvious problems. Mask errors cause routes to fail to connect to subnets