1 00:00:00,120 --> 00:00:06,330 So with dynamic net, once again you are creating a pool of inside global addresses. 2 00:00:06,689 --> 00:00:13,920 The reason why it's called dynamic rather than static is the router dynamically allocates IP addresses 3 00:00:13,920 --> 00:00:17,640 from the pool on a as needed basis. 4 00:00:17,820 --> 00:00:25,110 The mapping will be removed once communication ends, so there's no permanent 1 to 1 mapping that's 5 00:00:25,110 --> 00:00:27,750 always there, like you have with static Nat. 6 00:00:28,110 --> 00:00:36,090 With dynamic Nat, the nat translations automatically created when they needed and torn down or remove 7 00:00:36,090 --> 00:00:37,410 to when not needed. 8 00:00:39,820 --> 00:00:41,080 Now, as I've been explaining. 9 00:00:41,110 --> 00:00:44,650 Typically static nach is used when you have servers. 10 00:00:44,650 --> 00:00:50,650 So where router one is a server is an example that needs to be accessible from the outside or internet. 11 00:00:50,860 --> 00:00:56,410 Now, just to make sure that we cover the topics in the Q&A, I want to show you that router one is 12 00:00:56,410 --> 00:01:04,599 able to ping router three when static nat has been configured on router two so show run pipe include 13 00:01:04,599 --> 00:01:05,170 net. 14 00:01:05,170 --> 00:01:07,540 We can see the static net translation here. 15 00:01:07,990 --> 00:01:15,820 So we are translating ten 11128115 show IP net translations. 16 00:01:15,850 --> 00:01:19,000 Notice there is our static net translation. 17 00:01:19,000 --> 00:01:24,280 We are not netting the outside local and outside global in the static net. 18 00:01:24,730 --> 00:01:25,930 Let's do a debug. 19 00:01:26,080 --> 00:01:28,390 So debug IP net. 20 00:01:28,480 --> 00:01:32,530 And what I'll do now is I'll telnet to 8112. 21 00:01:35,200 --> 00:01:39,190 The Telnet connection is disconnected because I need a password on the side. 22 00:01:39,520 --> 00:01:43,100 But what I'd like you to see is the source IP address. 23 00:01:43,120 --> 00:01:47,020 Ten 111 was netted to 8115. 24 00:01:49,050 --> 00:01:52,080 That's the inside global address. 25 00:01:52,410 --> 00:01:55,650 The destination of the traffic is 8112. 26 00:01:57,400 --> 00:02:00,490 We had a reply back from 8112. 27 00:02:00,550 --> 00:02:06,240 Going to destination 8115, which is then translated to ten 111. 28 00:02:06,580 --> 00:02:14,110 So traffic from right to one to router three is having the source address translated and then the return 29 00:02:14,110 --> 00:02:16,900 traffic has the destination address translated. 30 00:02:18,200 --> 00:02:21,980 We are doing source address translation of this IP address. 31 00:02:22,460 --> 00:02:30,230 I'll enable telnet on the side, so I'll enable the two lines on this router. 32 00:02:33,250 --> 00:02:35,800 And enable a enable password. 33 00:02:37,820 --> 00:02:40,880 So we still running a debug show? 34 00:02:41,540 --> 00:02:48,740 Debug shows me my net debugging is enabled and I'll telnet from router one to router three again. 35 00:02:52,480 --> 00:02:55,150 We can see the net translations taking place again. 36 00:02:55,360 --> 00:02:57,520 Source to destination. 37 00:02:58,270 --> 00:03:00,370 I'll log in. 38 00:03:04,090 --> 00:03:05,680 And let's enter one character. 39 00:03:05,680 --> 00:03:06,550 So E. 40 00:03:08,210 --> 00:03:10,130 You can see for the character. 41 00:03:10,130 --> 00:03:14,300 E The source was translated from ten one one 1 to 8 115. 42 00:03:14,330 --> 00:03:16,910 Going to a destination of 8112. 43 00:03:17,680 --> 00:03:21,250 Reply came back and some other traffic was returned. 44 00:03:21,250 --> 00:03:25,360 So an acknowledgement to write a three type MN. 45 00:03:27,600 --> 00:03:29,820 We get to the same kind of translation. 46 00:03:30,390 --> 00:03:31,470 Hit enter. 47 00:03:33,380 --> 00:03:35,600 Same kind of translation is taking place. 48 00:03:35,840 --> 00:03:43,610 So for every character that I enter in the Telnet session, net translations are taking place with ten 49 00:03:43,610 --> 00:03:51,830 111 being translated to 81154 traffic going from inside to outside, and then 8115 is being translated 50 00:03:51,830 --> 00:03:56,150 back to ten 1114 traffic from the outside to the inside. 51 00:03:58,180 --> 00:04:01,810 In this example, we'll configure dynamic Nat in the topology. 52 00:04:01,810 --> 00:04:06,130 We have two routers router one and router four that are on the inside. 53 00:04:06,160 --> 00:04:11,830 They are connected via a switch to router two, which is going to do the actual network address. 54 00:04:11,830 --> 00:04:19,120 Translation We'll configure dynamic Nat on router two to allow both router one and right of four to 55 00:04:19,120 --> 00:04:24,580 access router three, which in our lab is deemed to be the internet. 56 00:04:24,580 --> 00:04:27,370 So the eight network is on the outside. 57 00:04:27,370 --> 00:04:28,690 That is the internet. 58 00:04:28,690 --> 00:04:36,160 Ten 110 is our internal network with these three devices connected to each other via switch one. 59 00:04:36,490 --> 00:04:42,640 Later on, I'll expand the topology to actually connect router three to the internet so that right of 60 00:04:42,640 --> 00:04:46,450 one and router four can connect to sites such as google.com.