200-301 pdf download

200-301 pdf download.10.1.1.150/32is directly connected, GigabitEthernetO/O ! Other routes omitted for brevityBecause of this particular matching error, R1's subnet places host A (10.1.1.9) outside of its own subnet range (10XP1.128/25, ranging from 10.1.1.129 to 10.1.1.254).R1 adds the route to which subnet 10.1.1.128/25 is connected to R1's routing table, and even broadcasts this route (in this case using OSPF) case is using OSPF) is broadcast to other routers in the network, as shown in Figure 5-4. All of the routers know how to route packets to subnet 10.1.1.128/25, but unfortunately, this route does not include host A's10.1.1.9 IP address.OSPF route for 8110.1.1.128 /25 is incorrectly matched to 10.1.1.9Figure 5-4 Router does not have a route that matches the address of host A10.1.1.9The host should use the same subnet mask as the default router, and the two devices should agree on what kind of subnet to have on the shared LAN. Otherwise, as this example shows, there will be problems immediately, or the problem will not be discovered until the other host is added. Typical root causes of DNS problemsWhen a host lists the wrong IP address for a DNS server, the symptoms are more obvious: any user activity that requires name resolution will fail. Assuming there is only one error in the DNS setup, any network test commands (such as ping and traceroute) will fail when using names, but if IP addresses are used instead of names, these commands all work fine.When pinging the host name of another host fails, but pinging the IP address of the same host works fine, the problem may be with DNS. As an example, suppose a user calls the Help Center complaining that they cannot connect to ServerlCSR from their PC and runs the ping serverl commandThen the CSR asks the user to run two commands on their own PC: a pingServerl command (which fails) and a ping1XPXP 1.1 command (which works). It is clear that there is some sort of problem with the DNS name resolution process on the user's PC.This book will not go into detail about how DNS works in the background, but the root causes of the next two DNS problems described fall under the CCENT and CCNA categories. , , , and . Incorrect DNS server settings. [Problem with the IP connection between the user host and the DNS server.