1 00:00:00,640 --> 00:00:04,730 Now let's turn our attention to Dynamic Host Configuration Protocol, 2 00:00:04,730 --> 00:00:09,640 or DHCP itself, particularly as it relates to the Windows Server role. 3 00:00:09,640 --> 00:00:14,010 The AZ‑800 exam mentions DHCP scopes and reservations. 4 00:00:14,010 --> 00:00:16,730 We're not going to do a full work up of DHCP. 5 00:00:16,730 --> 00:00:19,070 If you need remedial instruction on this, 6 00:00:19,070 --> 00:00:22,060 I would suggest you consult the Pluralsight library. Of course. 7 00:00:22,060 --> 00:00:26,780 DHCP is a way to automate the distribution and update of 8 00:00:26,780 --> 00:00:30,840 IPv4 and IPv6 addresses. It could be either public or 9 00:00:30,840 --> 00:00:32,670 private, but the only in my career, 10 00:00:32,670 --> 00:00:35,870 the only time I've ever seen DHCP is with private 11 00:00:35,870 --> 00:00:39,810 non‑internet routable address ranges. And a scope is simply 12 00:00:39,810 --> 00:00:42,240 an administrative IP address grouping. 13 00:00:42,240 --> 00:00:46,300 The most common scenario is that you'll have a scope for each subnet. 14 00:00:46,300 --> 00:00:51,140 And I mentioned earlier that DHCP is a broadcast‑based protocol, and if 15 00:00:51,140 --> 00:00:53,940 you know much about TCP, IP, and Ethernet, 16 00:00:53,940 --> 00:00:58,520 a broadcast domain is aligned to an IP subnet and you have router 17 00:00:58,520 --> 00:01:01,770 interfaces that are routing traffic among those subnets. 18 00:01:01,770 --> 00:01:05,410 And normally, routers will drop all broadcast traffic. 19 00:01:05,410 --> 00:01:10,170 So, in Windows Server, you can deploy the DHCP relay agent to 20 00:01:10,170 --> 00:01:13,660 get your DHCP traffic through router interfaces and to 21 00:01:13,660 --> 00:01:16,010 support multiple subnets; otherwise, 22 00:01:16,010 --> 00:01:18,760 it's something you can configure on the router itself, the 23 00:01:18,760 --> 00:01:22,830 so called IP helper address. You can set scope options, a 24 00:01:22,830 --> 00:01:24,980 couple different levels in DHCP. 25 00:01:24,980 --> 00:01:27,460 So the idea is that you've got client devices, 26 00:01:27,460 --> 00:01:30,270 not so much servers that are going to need a static address, 27 00:01:30,270 --> 00:01:33,480 but you've got client or endpoint devices that need an IP 28 00:01:33,480 --> 00:01:35,750 configuration when they come online. 29 00:01:35,750 --> 00:01:39,230 And if you're doing multi scopes on multi subnets 30 00:01:39,230 --> 00:01:41,970 based on where the request originates, 31 00:01:41,970 --> 00:01:47,840 the DHCP server will offer a lease from a scope that matches that subnet ID. 32 00:01:47,840 --> 00:01:51,540 And in addition to your IP address and subnet mask, 33 00:01:51,540 --> 00:01:56,290 you can deliver really a full complete configuration to the client. 34 00:01:56,290 --> 00:02:00,020 This is something you can deliver at the server level in which those 35 00:02:00,020 --> 00:02:04,350 options go to all scopes, or you could do scope by scope. You might do a 36 00:02:04,350 --> 00:02:08,610 scope by scope default gateway, for example, and you might deliver DNS 37 00:02:08,610 --> 00:02:10,530 server addresses at the server level. 38 00:02:10,530 --> 00:02:11,340 You see what I mean? 39 00:02:11,340 --> 00:02:16,310 Even more granularly, DHCP supports what are called user and vendor classes. 40 00:02:16,310 --> 00:02:19,960 Now I tend to stay away from the user classes because they're more 41 00:02:19,960 --> 00:02:24,780 proprietary, vendor classes are much more cross platform and open. 42 00:02:24,780 --> 00:02:28,260 But essentially, this allows you to get even more granular. I mean the 43 00:02:28,260 --> 00:02:32,870 scope option is going to apply to all leases or reservations on that 44 00:02:32,870 --> 00:02:37,450 entire subnet. You might have even more specific options for particular 45 00:02:37,450 --> 00:02:41,060 devices, maybe based on vendor. For users, 46 00:02:41,060 --> 00:02:46,840 you could separate user accounts and deliver DHCP‑specific options there. 47 00:02:46,840 --> 00:02:49,440 Now, we're not going to get that deep into it, I just want 48 00:02:49,440 --> 00:02:53,270 you to understand that that capability exists. Reservations 49 00:02:53,270 --> 00:02:55,290 are much more common in DHCP. 50 00:02:55,290 --> 00:03:00,460 This is a hard‑coded MAC address, the burned‑in address on your 51 00:03:00,460 --> 00:03:05,100 network interface to a specific IP address. Now, you could create 52 00:03:05,100 --> 00:03:08,860 reservations for your Windows Server infrastructure servers if you 53 00:03:08,860 --> 00:03:13,080 want to manage their IPs, in say IPAM, but at the same time, 54 00:03:13,080 --> 00:03:16,990 ensure that those systems always have the same address for them. 55 00:03:16,990 --> 00:03:20,910 That can create problems though because a lot of times the service that 56 00:03:20,910 --> 00:03:23,550 you're running on the server needs a static address. 57 00:03:23,550 --> 00:03:25,420 So in my practical experience, 58 00:03:25,420 --> 00:03:29,560 I see reservations more for things like network printers and other 59 00:03:29,560 --> 00:03:33,820 appliance‑type devices where you want to centrally manage the IP address 60 00:03:33,820 --> 00:03:36,580 and potentially update it, but for the time being, 61 00:03:36,580 --> 00:03:41,080 that device needs to be on a static, non‑changing IP address. 62 00:03:41,080 --> 00:03:43,210 And lastly, as you saw in the demo, 63 00:03:43,210 --> 00:03:46,850 IPAM can be really instrumental in managing reservations 64 00:03:46,850 --> 00:03:52,000 and managing DHCP and managing DNS. It's a really good service.