1 00:00:09,650 --> 00:00:17,110 This is one of multiple network address translation or not to trouble shooting videos in this typology 2 00:00:17,120 --> 00:00:23,660 we've been told that hosts on the inside network rodder one acting as host one writer for acting as 3 00:00:23,660 --> 00:00:30,740 host two and write a five acting as host three are not able to paying wrote a three acting as Google 4 00:00:31,090 --> 00:00:37,730 wrote a tuneless typologies configured as the NAT router so let's do some verification on brought a 5 00:00:37,760 --> 00:00:50,460 one to one able to ping the Google Server 8 8 8 8 and at the moment it's not let's do a debug on route 6 00:00:50,490 --> 00:00:58,200 to acting as on NAT router so debug IP not do the ping again. 7 00:00:58,370 --> 00:01:07,490 We are not getting any output on the console and we are monitoring debugs on the console at the moment 8 00:01:10,280 --> 00:01:14,480 so let's verify that traffic is getting to the default gateway. 9 00:01:14,600 --> 00:01:20,920 In this example the Rodda has a default gateway of 10 dot wandered wondered too far for a ping tendered 10 00:01:20,920 --> 00:01:25,430 one would want to fight for traffic gets to the default gateway. 11 00:01:25,820 --> 00:01:29,600 Let's trace to Google dot com. 12 00:01:29,600 --> 00:01:34,740 Traffic gets to the default gateway which is Rodda to. 13 00:01:34,740 --> 00:01:35,620 In this example 14 00:01:39,140 --> 00:01:41,210 it gets no further. 15 00:01:41,210 --> 00:01:46,520 So the Trace's timing out so let's determine if the problem is on the net to rodder. 16 00:01:46,550 --> 00:01:53,410 So show IP net statistics shows us statistics of the net configuration. 17 00:01:53,490 --> 00:01:54,760 Here's the command. 18 00:01:55,100 --> 00:01:58,480 We don't have any active translations. 19 00:01:58,580 --> 00:02:01,840 The outside interfaces gigabit is 0 1 which is correct. 20 00:02:01,850 --> 00:02:09,400 Per our diagram inside interfaces are gigabit to 0 0 0 2 0 3 which is correct. 21 00:02:09,410 --> 00:02:16,680 Per our diagram we have a dynamic translation configured for inside source addresses. 22 00:02:16,940 --> 00:02:24,570 We're using access list one and a Nat Poole called Net pool which has this Sublette mosque and this 23 00:02:24,580 --> 00:02:26,490 range of addresses. 24 00:02:26,800 --> 00:02:32,320 So let's do some more investigation show run pipe include Nat. 25 00:02:32,520 --> 00:02:35,280 These are the commands on the various interfaces. 26 00:02:35,370 --> 00:02:41,070 We were able to see which interfaces had not configured through this output here. 27 00:02:41,550 --> 00:02:47,680 So we know that some interfaces are configured as inside and one is configured as outside. 28 00:02:48,120 --> 00:02:50,310 And that's what this config is showing. 29 00:02:50,400 --> 00:02:57,630 You could if you wanted to make sure use commands such a show run interface and a individually interface 30 00:02:57,630 --> 00:03:04,590 such as gigabit 0 or 1 to confirm that the match has being configured correctly on the interface. 31 00:03:05,100 --> 00:03:13,110 But the statistics command has shown us that output is ready to show run pipe including that we can 32 00:03:13,110 --> 00:03:21,150 see here that a net command is being configured netting inside source addresses using access list 1. 33 00:03:21,270 --> 00:03:27,600 And in fact Paul called Net pool which is configured here and we can see a range of addresses in the 34 00:03:27,600 --> 00:03:34,710 pool and a subnet mask show access lists. 35 00:03:34,870 --> 00:03:40,970 We've got access list one configured and that's what's being referenced in the next statement. 36 00:03:41,260 --> 00:03:47,220 And we have some matches in the access list show IP interface brief. 37 00:03:47,560 --> 00:03:50,570 Can you see the problem. 38 00:03:50,630 --> 00:03:53,570 Let's have a look at Rotto for sure. 39 00:03:53,570 --> 00:03:55,070 I've been to face brief. 40 00:03:55,250 --> 00:04:01,270 Can you see the problem here let me give you another hint. 41 00:04:01,270 --> 00:04:05,400 Show interface give it a 0 0 show. 42 00:04:05,420 --> 00:04:06,580 Bruhn interface. 43 00:04:06,600 --> 00:04:13,480 Give it to 00 and on Rotto for a show run interface gigabit 00. 44 00:04:13,820 --> 00:04:23,050 Can you see the problem is another hint to show run pipe include access look at how this access list 45 00:04:23,050 --> 00:04:24,120 is configured. 46 00:04:24,940 --> 00:04:29,550 Compare that to the IP addresses of the host devices. 47 00:04:30,170 --> 00:04:36,430 OK so notice this host is in subnet 10 1 2 0. 48 00:04:36,560 --> 00:04:43,960 This host is in subnet 10 1 1 0 slushed 24 mosque here. 49 00:04:43,960 --> 00:04:54,790 However the access list is matching 10 is 0 1 10 0 2 and 10 0 3 host 5 acting as our third internal 50 00:04:55,240 --> 00:05:04,320 PC has an IP address 10 1 3 3 slushed 24 the sexist list is incorrect. 51 00:05:04,320 --> 00:05:20,790 So no access list one access list 1 permit 10 1 1 0 slushed 24 10 1 2 0 Slide 24 10 1 3 0 slash 24. 52 00:05:21,300 --> 00:05:26,230 So show access list this access list looks better. 53 00:05:26,520 --> 00:05:34,190 Let's confirm that networks are paying 8 8 8 8 Ping's succeeds. 54 00:05:34,290 --> 00:05:44,400 We see the net translations on Route 2 for that host peing 8 8 8 8 Ping's succeed and we see the net 55 00:05:44,420 --> 00:05:55,630 translations and on five of those internal host Ping's succeed and we see the net translations. 56 00:05:55,760 --> 00:06:05,880 So be careful with your access lists your access lists hefty match your data statements and be correct 57 00:06:05,940 --> 00:06:13,440 for the hosts in the typology this net statement is matching X-ists list one access list one is now 58 00:06:13,440 --> 00:06:15,020 correctly configured. 59 00:06:15,120 --> 00:06:18,970 So we see matches on the access list. 60 00:06:19,200 --> 00:06:22,770 That was an example of troubleshooting Network Address Translation. 61 00:06:22,950 --> 00:06:24,670 I hope you enjoyed this video. 62 00:06:24,900 --> 00:06:29,850 If he did please like it please subscribe to my YouTube channel. 63 00:06:29,850 --> 00:06:32,410 I wish you all the very best.