1 00:00:00,000 --> 00:00:01,230 In this section of the course, 2 00:00:01,230 --> 00:00:04,050 we're going to discuss troubleshooting network services. 3 00:00:04,050 --> 00:00:05,880 Now, network services are essential components 4 00:00:05,880 --> 00:00:08,340 that manage various operations within a computer network, 5 00:00:08,340 --> 00:00:10,200 and they work to facilitate the data exchange 6 00:00:10,200 --> 00:00:12,450 and communication across your network. 7 00:00:12,450 --> 00:00:15,120 Services like DHCP will handle the automatic assignment 8 00:00:15,120 --> 00:00:17,280 of IP addresses, or routing and switching, 9 00:00:17,280 --> 00:00:20,160 will direct traffic efficiently across your network. 10 00:00:20,160 --> 00:00:22,230 Now, additionally, security measures like firewalls 11 00:00:22,230 --> 00:00:23,700 will be used to protect our network 12 00:00:23,700 --> 00:00:25,500 and systems like DNS and NTP 13 00:00:25,500 --> 00:00:27,360 will ensure proper domain name resolution 14 00:00:27,360 --> 00:00:29,040 and time synchronization are happening 15 00:00:29,040 --> 00:00:30,510 on your network clients. 16 00:00:30,510 --> 00:00:32,670 But if any of these services begin to have issues, 17 00:00:32,670 --> 00:00:34,620 it'll start to create a myriad of other problems 18 00:00:34,620 --> 00:00:37,290 for your network clients and even your networks at large. 19 00:00:37,290 --> 00:00:38,850 So in this section of the course, 20 00:00:38,850 --> 00:00:39,810 we'll be focused solely 21 00:00:39,810 --> 00:00:41,820 on "Domain 5: Network Troubleshooting", 22 00:00:41,820 --> 00:00:45,030 and this time we'll be looking at Objective 5.3. 23 00:00:45,030 --> 00:00:46,627 Objective 5.3 states that, 24 00:00:46,627 --> 00:00:48,660 "Given a scenario, you must be able to troubleshoot 25 00:00:48,660 --> 00:00:50,940 common issues with network services." 26 00:00:50,940 --> 00:00:53,910 First, we'll look at issues surrounding duplicate addresses. 27 00:00:53,910 --> 00:00:55,560 Duplicate address issues will occur 28 00:00:55,560 --> 00:00:57,270 when two devices on the same network 29 00:00:57,270 --> 00:00:59,580 are assigned or claim the same IP address 30 00:00:59,580 --> 00:01:02,310 and this leads to conflicts and connectivity problems. 31 00:01:02,310 --> 00:01:04,890 Then we're going to discuss DHCP issues. 32 00:01:04,890 --> 00:01:07,320 DHCP issues can stem from misconfigurations 33 00:01:07,320 --> 00:01:08,970 or exhausted address pools 34 00:01:08,970 --> 00:01:11,430 that can prevent devices from obtaining the necessary IP 35 00:01:11,430 --> 00:01:14,280 information that they need in order to join your network. 36 00:01:14,280 --> 00:01:16,560 Next, we'll learn about routing issues. 37 00:01:16,560 --> 00:01:19,320 Routing issues often are manifested as misdirected 38 00:01:19,320 --> 00:01:21,690 or lost out of packets that end up causing delays 39 00:01:21,690 --> 00:01:24,960 or failures in the data reaching its intended destination. 40 00:01:24,960 --> 00:01:27,690 After that, we're going to explore switching and routing loops. 41 00:01:27,690 --> 00:01:30,030 Switching and routing loops can create broadcast storms 42 00:01:30,030 --> 00:01:31,710 that overwhelm our network resources, 43 00:01:31,710 --> 00:01:33,360 and this leads to significant slowdowns 44 00:01:33,360 --> 00:01:35,520 or complete network outages for us. 45 00:01:35,520 --> 00:01:37,830 Then we're going to cover firewall issues. 46 00:01:37,830 --> 00:01:40,470 Firewall issues may arise from overly strict rules 47 00:01:40,470 --> 00:01:42,840 or misconfigurations that block legitimate traffic 48 00:01:42,840 --> 00:01:45,060 or allow unauthorized access. 49 00:01:45,060 --> 00:01:47,760 Next, we'll look at IP configuration issues. 50 00:01:47,760 --> 00:01:50,910 IP configuration issues include incorrect subnet mass, 51 00:01:50,910 --> 00:01:53,040 gateways or DNS server addresses 52 00:01:53,040 --> 00:01:55,350 that impede proper network communication. 53 00:01:55,350 --> 00:01:57,990 After that, we'll be exploring VLAN issues. 54 00:01:57,990 --> 00:02:00,720 VLAN issues typically involve incorrect port assignments 55 00:02:00,720 --> 00:02:03,570 or tagging, and this can lead to a segmentation of devices 56 00:02:03,570 --> 00:02:06,180 and this hinders your inner VLAN communications. 57 00:02:06,180 --> 00:02:09,449 Then we'll be discussing DNS and NTP issues. 58 00:02:09,449 --> 00:02:12,420 DNS issues can prevent users from accessing websites 59 00:02:12,420 --> 00:02:14,310 because they can't resolve domain names. 60 00:02:14,310 --> 00:02:15,780 And NTP issues can lead 61 00:02:15,780 --> 00:02:17,850 to time synchronization problems across all 62 00:02:17,850 --> 00:02:19,980 of your network clients and devices. 63 00:02:19,980 --> 00:02:22,170 Finally, we'll take a short quiz to see what you learned 64 00:02:22,170 --> 00:02:23,460 during this section of the course 65 00:02:23,460 --> 00:02:25,500 and review your answers to ensure you know why the right 66 00:02:25,500 --> 00:02:27,780 answers were right and the wrong answers were wrong. 67 00:02:27,780 --> 00:02:30,090 So if you're ready, let's get started troubleshooting 68 00:02:30,090 --> 00:02:32,440 network services in this section of the course.