1 00:00:00,010 --> 00:00:02,318 Okay now lets talk about 2 00:00:02,318 --> 00:00:03,800 Elastic Network Interfaces or ENI. 3 00:00:03,800 --> 00:00:05,950 So if you hear me say ENI I mean 4 00:00:05,950 --> 00:00:07,740 Elastic Network Interfaces. 5 00:00:07,740 --> 00:00:10,310 They're a logical component in a VPC 6 00:00:10,310 --> 00:00:13,260 and they represent a virtual network card. 7 00:00:13,260 --> 00:00:17,210 So they're what gives EC2 Instances access to the network, 8 00:00:17,210 --> 00:00:19,730 but they're used outside EC2 Instances as well 9 00:00:19,730 --> 00:00:21,660 as we'll see later in this course. 10 00:00:21,660 --> 00:00:24,250 So for example we have an availability zone 11 00:00:24,250 --> 00:00:26,380 and we have one EC2 Instance 12 00:00:26,380 --> 00:00:30,870 and to it is attached on eth0, your primary ENI 13 00:00:30,870 --> 00:00:34,510 and this will provide your EC2 Instance network connectivity 14 00:00:34,510 --> 00:00:36,870 and for example, a private IP. 15 00:00:36,870 --> 00:00:39,930 So each ENI can have the following attributes. 16 00:00:39,930 --> 00:00:43,210 Number one it can have a Primary private IPv4 17 00:00:43,210 --> 00:00:46,950 and one or more secondary IPv4. Okay. 18 00:00:46,950 --> 00:00:49,940 So in this example, I have one of zero but 19 00:00:49,940 --> 00:00:54,270 you are more than welcomed to add a secondary ENI to EC2 20 00:00:54,270 --> 00:00:55,639 and that will be eth1 21 00:00:55,639 --> 00:01:00,250 and this will give you another private IPv4 as well, okay. ` 22 00:01:00,250 --> 00:01:05,250 Each ENI can also have an elastic IPv4 per private IPv4 23 00:01:06,060 --> 00:01:07,930 or one or more public IPv4, 24 00:01:07,930 --> 00:01:10,330 so it gives you a private and a public IP 25 00:01:10,330 --> 00:01:11,800 as will see in the hands-on. 26 00:01:11,800 --> 00:01:14,110 You can have one or more security groups attached 27 00:01:14,110 --> 00:01:15,400 to your ENI. 28 00:01:15,400 --> 00:01:17,390 You can have a Mac address attached to it 29 00:01:17,390 --> 00:01:20,140 and other things but I've just give you 30 00:01:20,140 --> 00:01:22,640 the most important bits right now in this lecture. 31 00:01:22,640 --> 00:01:25,660 And you can create ENI's independently from 32 00:01:25,660 --> 00:01:26,870 your EC2 instances 33 00:01:26,870 --> 00:01:28,160 and attach them on the fly 34 00:01:28,160 --> 00:01:31,560 or move them from EC2 instances for failover. 35 00:01:31,560 --> 00:01:33,370 So, let's have a look at what it looks like. 36 00:01:33,370 --> 00:01:34,740 And by the way, they're bounded 37 00:01:34,740 --> 00:01:37,352 to a specific availability zone or AZ. 38 00:01:37,352 --> 00:01:40,020 So that means that if you create a ENI in the specific AZ, 39 00:01:40,020 --> 00:01:42,610 you can only have it bound to that specific AZ. 40 00:01:42,610 --> 00:01:44,410 So here's another issue to instance 41 00:01:44,410 --> 00:01:47,130 and it has another ENI attached to it. 42 00:01:47,130 --> 00:01:50,040 And for example, we can do is we can move eth1 43 00:01:50,040 --> 00:01:53,740 from the first EC2 instance into the second EC2 Instance 44 00:01:53,740 --> 00:01:55,650 to move that private IP. 45 00:01:55,650 --> 00:01:58,170 And what it means is that that private IP will change 46 00:01:58,170 --> 00:01:59,790 from the first issue to instance 47 00:01:59,790 --> 00:02:01,970 and will be attached to the second EC2 Instance. 48 00:02:01,970 --> 00:02:04,110 And it's very very helpful for failovers. 49 00:02:04,110 --> 00:02:07,070 For example, if you're easy to instance is accessed 50 00:02:07,070 --> 00:02:09,229 by a private static IP, 51 00:02:09,229 --> 00:02:10,770 then you can move the IP around between 52 00:02:10,770 --> 00:02:13,750 these two instances for failover purposes, okay. 53 00:02:13,750 --> 00:02:14,870 So let's have a look in the hands-on 54 00:02:14,870 --> 00:02:16,310 to see what it looks like.