WEBVTT 1 00:00.000 --> 00:05.040 Well, the purpose of this lab challenge is to combine the concepts of VRF and 2 00:05.040 --> 00:05.800 GRE and 3 00:05.800 --> 00:09.760 make sure that we can configure each one individually, but also then make sure 4 00:09.760 --> 00:10.440 we can 5 00:10.440 --> 00:12.160 combine them together. 6 00:12.160 --> 00:15.330 And so what we're going to do is we're going to start off just by getting our 7 00:15.330 --> 00:16.800 tunnel established, 8 00:16.800 --> 00:21.290 making sure we can ping from router 5 to router 6 over there at the parameters 9 00:21.290 --> 00:21.880 there in our 10 00:21.880 --> 00:23.320 topology. 11 00:23.320 --> 00:26.800 And at that point, we will have built a GRE tunnel. 12 00:26.800 --> 00:30.130 And then we're going to take a quick moment to check that recursive routing WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 12 00:26.800 --> 00:30.130 And then we're going to take a quick moment to check that recursive routing 13 00:30.130 --> 00:30.700 situation 14 00:30.700 --> 00:32.600 and what might cause that. 15 00:32.600 --> 00:36.280 And then to prevent that in the future, we're going to create a different VRF 16 00:36.280 --> 00:37.520 for this OSPF 17 00:37.520 --> 00:39.960 domain, which is our underlay. 18 00:39.960 --> 00:44.870 We're going to establish that as a VRF, establish that OSPF is now part of the 19 00:44.870 --> 00:46.480 new VRF, and 20 00:46.480 --> 00:51.920 then we want to form the tunnel across that new VRF as well. 21 00:51.920 --> 00:56.540 So if you haven't yet done so, be sure to hit the pause button on this video 22 00:56.540 --> 00:57.240 and go and 23 00:57.240 --> 00:58.400 go through the lab yourself. 24 00:58.400 --> 01:02.600 You just have to click the link in the skill to fire up this topology of the WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 24 00:58.400 --> 01:02.600 You just have to click the link in the skill to fire up this topology of the 25 01:02.600 --> 01:03.360 exact same 26 01:03.360 --> 01:08.590 topology here where we've got the six different router tabs available, and you 27 01:08.590 --> 01:09.400 can click through 28 01:09.400 --> 01:12.280 and perform all of these steps yourself. 29 01:12.280 --> 01:16.460 Once you're done and you've given it a good shot, if you need any to review any 30 01:16.460 --> 01:16.880 of the 31 01:16.880 --> 01:20.650 steps, then that's what we're about to do is kind of go through this here 32 01:20.650 --> 01:21.320 together. 33 01:21.320 --> 01:26.140 So let's go ahead and start with task one here, which is simply building the 34 01:26.140 --> 01:26.920 GRE tunnel 35 01:26.920 --> 01:29.160 between routers three and four. 36 01:29.160 --> 01:35.650 So what we're going to do is we're going to start off on router three, get into WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 36 01:29.160 --> 01:35.650 So what we're going to do is we're going to start off on router three, get into 37 01:35.650 --> 01:36.200 global 38 01:36.200 --> 01:40.320 configuration mode and configure that tunnel interface. 39 01:40.320 --> 01:46.960 And I'm going to create that tunnel source of 10, 0, 13, and 3. 40 01:46.960 --> 01:52.920 And tunnel destination is router four, 10, 0, 24, dot four. 41 01:52.920 --> 01:56.600 And then I'm going to go ahead and configure my p address while I'm here. 42 01:56.600 --> 02:00.360 That would be 34 dot three slash 24. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 42 01:56.600 --> 02:00.360 That would be 34 dot three slash 24. 43 02:00.360 --> 02:03.970 And now I'm going to go over to router four and basically do the same thing 44 02:03.970 --> 02:04.600 interface 45 02:04.600 --> 02:15.520 tunnel zero tunnel source 10, 0, 24, 4 tunnel destination 10, 0, 13, 3. 46 02:15.520 --> 02:20.240 And then IP address 10, 0, 34, this is dot four. 47 02:20.240 --> 02:23.360 Okay, so that was quick. 48 02:23.360 --> 02:24.840 Let's find out if this worked. 49 02:24.840 --> 02:29.410 So I'm just going to ping across the tunnel to 34 dot three, and we've already 50 02:29.410 --> 02:29.960 got our 51 02:29.960 --> 02:30.960 ping. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 51 02:29.960 --> 02:30.960 ping. 52 02:30.960 --> 02:34.500 So it's one of the best ways to just test to see if the tunnel is up is just p 53 02:34.500 --> 02:34.960 inging the 54 02:34.960 --> 02:37.840 other side via the tunnel. 55 02:37.840 --> 02:43.560 And so next we're on to task two, which is activating ERP across the tunnel. 56 02:43.560 --> 02:46.640 So we're already already running ERP here. 57 02:46.640 --> 02:52.060 If I do a section ERP on router four, we should see I've got an ERP 58 02:52.060 --> 02:54.200 relationship with router 59 02:54.200 --> 02:57.000 six, router three should have one with router five. 60 02:57.000 --> 02:58.560 Let's just go confirm that. 61 02:58.560 --> 03:03.520 I get it's done show IP, ERP neighbor, I suppose. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 61 02:58.560 --> 03:03.520 I get it's done show IP, ERP neighbor, I suppose. 62 03:03.520 --> 03:04.720 So there we go. 63 03:04.720 --> 03:07.080 And then show IP, ERP neighbor on this side. 64 03:07.080 --> 03:08.080 And there we go. 65 03:08.080 --> 03:10.920 So we do see that and we see the configuration. 66 03:10.920 --> 03:15.240 So we want to do is want to add the tunnel into this configuration. 67 03:15.240 --> 03:19.760 Now we haven't yet gotten to ERP here within the encore course. 68 03:19.760 --> 03:24.840 And so we're not going to spend a whole lot of time on the ERP configuration. 69 03:24.840 --> 03:30.010 We mostly just want to do the basic step of adding in a new network statement WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 69 03:24.840 --> 03:30.010 We mostly just want to do the basic step of adding in a new network statement 70 03:30.010 --> 03:31.520 of 10 dot 71 03:31.520 --> 03:36.280 zero dot 34 dot four with all zeros. 72 03:36.280 --> 03:41.320 Now we'll activate it only on the tunnel interface since that matches the 73 03:41.320 --> 03:43.000 address perfectly. 74 03:43.000 --> 03:47.640 Router ERP 10 network 10 dot zero dot 34 dot three. 75 03:47.640 --> 03:53.910 And we should see that as soon as I hit enter here that the tunnel or the ERP 76 03:53.910 --> 03:55.360 neighbor forms 77 03:55.360 --> 03:57.840 over the tunnel and it did. 78 03:57.840 --> 04:00.560 So that is task two. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 78 03:57.840 --> 04:00.560 So that is task two. 79 04:00.560 --> 04:02.440 And at this point we have ERP everywhere. 80 04:02.440 --> 04:06.570 So I should be able to get onto router five and ping over to six dot six dot 81 04:06.570 --> 04:07.360 six dot six, 82 04:07.360 --> 04:09.660 which is router six's loopback address. 83 04:09.660 --> 04:11.800 So we're going all the way from this five. 84 04:11.800 --> 04:13.800 Well, actually we didn't specify the source. 85 04:13.800 --> 04:18.440 We didn't specify the source here source of all five. 86 04:18.440 --> 04:19.440 There we go. 87 04:19.440 --> 04:23.380 So now we're truly going from five dot five dot five dot five the six dot six 88 04:23.380 --> 04:23.800 dot six 89 04:23.800 --> 04:24.880 dot six. 90 04:24.880 --> 04:28.800 And so we have full connectivity. 91 04:28.800 --> 04:34.060 But now we want to pause before we get on to the VRF configuration and see the WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 91 04:28.800 --> 04:34.060 But now we want to pause before we get on to the VRF configuration and see the 92 04:34.060 --> 04:34.600 routing 93 04:34.600 --> 04:39.210 recursion issue that might occur, whether it's in production or other lab 94 04:39.210 --> 04:40.400 environments. 95 04:40.400 --> 04:45.560 And so we're going to get onto router three and we're going to advertise. 96 04:45.560 --> 04:49.440 Let's get onto router ERP 10 here. 97 04:49.440 --> 04:56.140 And what we're going to do is we're going to advertise this tunnel source via 98 04:56.140 --> 04:57.360 the tunnel. 99 04:57.360 --> 04:59.160 So I'm going to advertise this subnet. 100 04:59.160 --> 05:01.640 Right now that subnet's only part of the OSPF domain. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 100 04:59.160 --> 05:01.640 Right now that subnet's only part of the OSPF domain. 101 05:01.640 --> 05:04.040 It's not part of ERP. 102 05:04.040 --> 05:08.120 And this router, which has the route this way, is going to know that, hey, this 103 05:08.120 --> 05:08.720 is my only 104 05:08.720 --> 05:09.720 route. 105 05:09.720 --> 05:12.820 It happens to have administrative distance of 110, but it's the only way I know 106 05:12.820 --> 05:13.160 how to 107 05:13.160 --> 05:15.640 get to that address. 108 05:15.640 --> 05:18.800 Well as soon as it comes in this side, it's going to see ERP having an 109 05:18.800 --> 05:19.800 administrative 110 05:19.800 --> 05:27.960 distance of 90 and saying, oh, I've got a better route to 10.0.13.0/24. 111 05:27.960 --> 05:32.520 Therefore I'm going to form the tunnel out the tunnel, which is a recursive WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 111 05:27.960 --> 05:32.520 Therefore I'm going to form the tunnel out the tunnel, which is a recursive 112 05:32.520 --> 05:33.320 problem. 113 05:33.320 --> 05:36.280 So let's go ahead and see that in action. 114 05:36.280 --> 05:37.560 I've gotten onto router three. 115 05:37.560 --> 05:45.080 I just need to advertise that network in to the, I guess, across the tunnel. 116 05:45.080 --> 05:46.080 So I could do one of two things. 117 05:46.080 --> 05:51.510 I could do the physical address like we typically do here with all zeros for 118 05:51.510 --> 05:52.640 the wildcard to 119 05:52.640 --> 05:55.120 specify this exact address. 120 05:55.120 --> 05:59.530 I'm going to look for an interface with that exact address and activate that 121 05:59.530 --> 06:00.200 for ERP. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 121 05:59.530 --> 06:00.200 for ERP. 122 06:00.200 --> 06:04.250 Or I could do what happens to occur in a lot of even production environments 123 06:04.250 --> 06:04.920 where we just 124 06:04.920 --> 06:09.330 say network tend does here it is here it is zero, which activates the ERP and 125 06:09.330 --> 06:09.880 all of my 126 06:09.880 --> 06:11.120 interfaces. 127 06:11.120 --> 06:12.760 So what if we were to do that? 128 06:12.760 --> 06:16.480 Well, because I activated on all interfaces, gig one zero is going to be 129 06:16.480 --> 06:17.400 advertised in. 130 06:17.400 --> 06:22.520 Now, if I just sit here on router three, I might think everything is good until 131 06:22.520 --> 06:23.120 ERP times 132 06:23.120 --> 06:24.120 out. 133 06:24.120 --> 06:25.800 Look at that timing couldn't have been better. 134 06:25.800 --> 06:27.080 ERP timed out. 135 06:27.080 --> 06:30.360 Why did we lose our ERP neighbor across tunnel zero? WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 135 06:27.080 --> 06:30.360 Why did we lose our ERP neighbor across tunnel zero? 136 06:30.360 --> 06:32.320 Well, let's go look at router four. 137 06:32.320 --> 06:37.150 Router four who just got this new advertised route decided, hey, that's a 138 06:37.150 --> 06:38.320 better route. 139 06:38.320 --> 06:43.310 I'm going to go that way and then we see tunnel is temporarily disabled due to 140 06:43.310 --> 06:44.880 recursive routing 141 06:44.880 --> 06:47.960 along with this tunnel recurved down. 142 06:47.960 --> 06:52.120 I want to say that error message. 143 06:52.120 --> 06:54.280 So this is exactly what we'd expect. 144 06:54.280 --> 06:57.120 Now here, look, what's going to try again? 145 06:57.120 --> 06:59.960 It just brought the tunnel up to try it. 146 06:59.960 --> 07:04.250 And because again, the ERP route went away, it does not physically shut the WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 146 06:59.960 --> 07:04.250 And because again, the ERP route went away, it does not physically shut the 147 07:04.250 --> 07:04.960 interface 148 07:04.960 --> 07:05.960 down. 149 07:05.960 --> 07:11.440 This decides, hey, we're going to temporarily disable the tunnel. 150 07:11.440 --> 07:15.480 Then we lost ERP because of that, which we saw on router three. 151 07:15.480 --> 07:18.300 And then eventually we said, all right, you know what, let's go ahead and try 152 07:18.300 --> 07:18.800 again. 153 07:18.800 --> 07:21.440 So we disable the disablement. 154 07:21.440 --> 07:26.710 We enable tunnel zero, bring it up, which of course leads to our ERP 155 07:26.710 --> 07:28.760 neighborhood forming, 156 07:28.760 --> 07:32.230 which leads to this new route being advertised again, which leads to it being WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 156 07:28.760 --> 07:32.230 which leads to this new route being advertised again, which leads to it being 157 07:32.230 --> 07:32.920 disabled due 158 07:32.920 --> 07:36.800 to recursive routing, which leads to the tunnel going down. 159 07:36.800 --> 07:41.250 And then all of a sudden we decide eventually to bring the tunnel back up and 160 07:41.250 --> 07:42.200 life continues 161 07:42.200 --> 07:43.960 to loop forever. 162 07:43.960 --> 07:48.080 We're never going to recover from this because we have done something we should 163 07:48.080 --> 07:48.760 never have 164 07:48.760 --> 07:53.410 done, which is on router three, we advertised the underlay source and 165 07:53.410 --> 07:54.560 destination. 166 07:54.560 --> 08:00.760 Everyone say it there, the tunnel endpoint was advertised across the tunnel. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 166 07:54.560 --> 08:00.760 Everyone say it there, the tunnel endpoint was advertised across the tunnel. 167 08:00.760 --> 08:03.800 And so that's something we always want to prevent. 168 08:03.800 --> 08:09.100 So let's go and get back into router ERP 10 and say, no network 10 dot 0 dot 0 169 08:09.100 --> 08:10.360 dot 0, 170 08:10.360 --> 08:11.440 remove that statement. 171 08:11.440 --> 08:17.840 We'll just do a quick show run section ERP to make sure that it looks good. 172 08:17.840 --> 08:23.390 We should only see the couple network statements, one for the tunnel and one 173 08:23.390 --> 08:24.680 for the physical 174 08:24.680 --> 08:29.840 address, which we do right here, physical address facing router five, by the 175 08:29.840 --> 08:30.480 way. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 175 08:29.840 --> 08:30.480 way. 176 08:30.480 --> 08:32.240 And so now ERP is back. 177 08:32.240 --> 08:35.780 So we can get rid of all of those markings on the diagram because we got rid of 178 08:35.780 --> 08:36.160 that 179 08:36.160 --> 08:37.160 advertisement. 180 08:37.160 --> 08:39.680 So a couple of things about this. 181 08:39.680 --> 08:43.730 First of all, we can prevent it like we just did simply by not advertising that 182 08:43.730 --> 08:44.640 interface. 183 08:44.640 --> 08:48.120 Things do get a little trickier if we're running ERP everywhere, which is 184 08:48.120 --> 08:49.000 usually not what we 185 08:49.000 --> 08:50.440 want to do. 186 08:50.440 --> 08:55.000 Here we happen to have OSPF running in the underlay subnets. 187 08:55.000 --> 08:59.240 But if we were running ERP down here, this would be a little bit more tricky. 188 08:59.240 --> 09:04.490 Now granted, we do have the scenario where, again, the metric is low on the WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 188 08:59.240 --> 09:04.490 Now granted, we do have the scenario where, again, the metric is low on the 189 09:04.490 --> 09:05.320 tunnel. 190 09:05.320 --> 09:06.880 And so that should prevent it as well. 191 09:06.880 --> 09:10.010 There's a lot of things in place to prevent this, but we do need to be aware 192 09:10.010 --> 09:10.600 that it could 193 09:10.600 --> 09:11.700 occur. 194 09:11.700 --> 09:15.820 And the best way to prevent it is simply to place this underlay into its own 195 09:15.820 --> 09:17.000 routing domain, 196 09:17.000 --> 09:19.040 which is of course a VRF. 197 09:19.040 --> 09:21.280 So let's go ahead and move on to task three. 198 09:21.280 --> 09:23.920 And we're going to create a VRF on router three. 199 09:23.920 --> 09:26.200 So that is the VRF definition command. 200 09:26.200 --> 09:31.400 I'm going to use the word underlay and all caps in order to name this one WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 200 09:26.200 --> 09:31.400 I'm going to use the word underlay and all caps in order to name this one 201 09:31.400 --> 09:32.600 address family 202 09:32.600 --> 09:35.800 IPv4 activate that. 203 09:35.800 --> 09:43.070 And now I need to place this physical interface gig one zero into the underlay 204 09:43.070 --> 09:44.080 VRF. 205 09:44.080 --> 09:49.370 So interface gig one zero if I do a show run on gig one zero, I should see that 206 09:49.370 --> 09:50.840 it's 13.3. 207 09:50.840 --> 09:57.680 I'm going to say VRF forwarding underlay, which removes the IP addresses. 208 09:57.680 --> 10:03.640 And now I can simply grab this configuration and paste it back in. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 208 09:57.680 --> 10:03.640 And now I can simply grab this configuration and paste it back in. 209 10:03.640 --> 10:08.320 Next, I need the tunnel is still down. 210 10:08.320 --> 10:12.790 So let's first of all, at this point, we should still be able to ping the 211 10:12.790 --> 10:14.400 tunnel destination. 212 10:14.400 --> 10:18.830 So if I use my ping, keeping in mind, I have to specify the underlay VRF now, I 213 10:18.830 --> 10:19.040 should 214 10:19.040 --> 10:23.800 be able to ping out the underlay to 10.0.24.4. 215 10:23.800 --> 10:28.360 Is that the right? 216 10:28.360 --> 10:30.080 Yeah, well, we did not get it. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 216 10:28.360 --> 10:30.080 Yeah, well, we did not get it. 217 10:30.080 --> 10:33.200 All right, so let's make sure that everything looks good here. 218 10:33.200 --> 10:42.160 So that was ping VR VRF gig one zero underlay 13.3. 219 10:42.160 --> 10:44.240 That is the correct. 220 10:44.240 --> 10:46.120 Oh, okay. 221 10:46.120 --> 10:47.120 I jumped the gun. 222 10:47.120 --> 10:49.320 I meant to ping router one here. 223 10:49.320 --> 10:51.760 We should be able to ping across to router one. 224 10:51.760 --> 10:53.520 So let's do that. 225 10:53.520 --> 10:58.000 13.1 should be router one and we can ping. 226 10:58.000 --> 11:01.560 So why can we ping router one but not router four? WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 226 10:58.000 --> 11:01.560 So why can we ping router one but not router four? 227 11:01.560 --> 11:05.840 Because we haven't updated OSPF to exist inside of this VRF. 228 11:05.840 --> 11:10.440 OSPF on router three still exists inside the default VRF. 229 11:10.440 --> 11:14.040 And so let's go ahead and add OSPF into make it VRF aware. 230 11:14.040 --> 11:21.280 I'm going to say no router OSPF one and then say router OSPF one, put it into 231 11:21.280 --> 11:22.640 the VRF and 232 11:22.640 --> 11:28.160 add my network statement, which should just be that interface 10.0.13.3. 233 11:28.160 --> 11:30.320 Oops, area zero. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 233 11:28.160 --> 11:30.320 Oops, area zero. 234 11:30.320 --> 11:32.360 I'm doing too much ERP lately. 235 11:32.360 --> 11:37.720 They'll just use area zero for OSPF one there and boom, we've got OSPF. 236 11:37.720 --> 11:42.840 Now I should be able to use that same command to ping router four and there we 237 11:42.840 --> 11:43.360 go. 238 11:43.360 --> 11:49.800 So router three is primed and ready to build a tunnel across the VRF. 239 11:49.800 --> 11:51.400 So how do we go about doing that? 240 11:51.400 --> 11:56.530 Well, I simply have to get onto the tunnel interface and I use the command 241 11:56.530 --> 11:57.360 tunnel VRF 242 11:57.360 --> 11:58.800 underlay. 243 11:58.800 --> 12:03.110 And now the tunnel knows to build itself across the underlay, even though the WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 243 11:58.800 --> 12:03.110 And now the tunnel knows to build itself across the underlay, even though the 244 12:03.110 --> 12:04.560 tunnel itself 245 12:04.560 --> 12:07.320 is still part of the overlay. 246 12:07.320 --> 12:12.590 So the tunnel is up, ERP is running and this brings up an interesting point 247 12:12.590 --> 12:13.320 because it 248 12:13.320 --> 12:19.060 if I go to router five right now, I can ping across the tunnel and yet I've 249 12:19.060 --> 12:20.200 only created 250 12:20.200 --> 12:22.440 this VRF on router three. 251 12:22.440 --> 12:28.330 Keep in mind VRFs in a VRF light scenario, meaning no MPLS tagging is occurring 252 12:28.330 --> 12:28.520 . 253 12:28.520 --> 12:34.900 VRFs are a local concept only, meaning that router one doesn't need to know it WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 253 12:28.520 --> 12:34.900 VRFs are a local concept only, meaning that router one doesn't need to know it 254 12:34.900 --> 12:35.440 's in a 255 12:35.440 --> 12:36.440 VRF. 256 12:36.440 --> 12:40.280 Router one can operate in the default VRF, no problem. 257 12:40.280 --> 12:43.080 Router two can operate in the default VRF, no problem. 258 12:43.080 --> 12:48.620 Router four is by the end of this going to be participating in the underlay VRF 259 12:48.620 --> 12:48.960 . 260 12:48.960 --> 12:52.120 I could call it underlay, I could call it CBT. 261 12:52.120 --> 12:58.000 I don't have to call it the same thing because it's local to router four. 262 12:58.000 --> 13:00.440 The VRF on router three is local to router three. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 262 12:58.000 --> 13:00.440 The VRF on router three is local to router three. 263 13:00.440 --> 13:05.130 So even though I've only configured the VRF for router three because everything 264 13:05.130 --> 13:05.480 is in 265 13:05.480 --> 13:09.880 place on router three, it's all going to work and it is working. 266 13:09.880 --> 13:10.880 Everything's great. 267 13:10.880 --> 13:14.100 We're not doing ping router six, but we're not done until we've finished our 268 13:14.100 --> 13:14.880 configuration 269 13:14.880 --> 13:17.400 on router four, so let's go do that. 270 13:17.400 --> 13:21.630 We're basically just going to do the exact same thing as we just did on router 271 13:21.630 --> 13:22.280 three. 272 13:22.280 --> 13:27.650 I'm going to do a config T, make our VRF definition and I will just keep the 273 13:27.650 --> 13:29.120 same name for clarity 274 13:29.120 --> 13:35.200 sake, activate it on the address family for IPv4 and then we'll get on to that WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 274 13:29.120 --> 13:35.200 sake, activate it on the address family for IPv4 and then we'll get on to that 275 13:35.200 --> 13:36.040 physical 276 13:36.040 --> 13:40.360 interface interface gig two zero. 277 13:40.360 --> 13:42.720 We'll look at that interface to get the IP address. 278 13:42.720 --> 13:49.140 I always like to do that and then say VRF forwarding underlay wipes the IP 279 13:49.140 --> 13:50.200 addresses 280 13:50.200 --> 13:52.720 and now I can just grab it right back. 281 13:52.720 --> 13:54.920 That's a beautiful thing. 282 13:54.920 --> 13:59.760 All right, so next I'm going to let's go ahead and wipe OSPF. 283 13:59.760 --> 14:07.930 So I'm going to say no router OSPF one and then say router OSPF one with a VRF WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 283 13:59.760 --> 14:07.930 So I'm going to say no router OSPF one and then say router OSPF one with a VRF 284 14:07.930 --> 14:09.400 of underlay 285 14:09.400 --> 14:10.400 work. 286 14:10.400 --> 14:17.320 The physical network is when we just did 10 dot zero dot 24 dot four all zeros. 287 14:17.320 --> 14:20.760 Here is zero OSPF is established. 288 14:20.760 --> 14:22.440 Pinging should be working. 289 14:22.440 --> 14:26.400 Ping VRF underlay 10 dot zero dot 13 dot three. 290 14:26.400 --> 14:30.360 That would be router three and I just came across the underlay routing is WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 290 14:26.400 --> 14:30.360 That would be router three and I just came across the underlay routing is 291 14:30.360 --> 14:31.120 working. 292 14:31.120 --> 14:34.790 Everything's good except our tunnel is still on a downstate and the reason is 293 14:34.790 --> 14:35.360 because I 294 14:35.360 --> 14:37.760 haven't told the tunnel to build across the underlay. 295 14:37.760 --> 14:41.970 Still trying to build across the default VRF and that some of those subnets no 296 14:41.970 --> 14:42.460 longer 297 14:42.460 --> 14:44.680 exist in the default VRF. 298 14:44.680 --> 14:51.300 So all I need to do is use that tunnel VRF underlay command and we should see 299 14:51.300 --> 14:52.160 the tunnel 300 14:52.160 --> 14:57.140 come back up and not only did it come back up but ERP was established over it 301 14:57.140 --> 14:58.600 immediately. 302 14:58.600 --> 15:04.350 So that's a force of habit to save the configuration but the big test is hey WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 302 14:58.600 --> 15:04.350 So that's a force of habit to save the configuration but the big test is hey 303 15:04.350 --> 15:05.500 can we ping from 304 15:05.500 --> 15:07.320 router five to router six. 305 15:07.320 --> 15:11.980 I'm going to go to router five ping router six from the router five loop back 306 15:11.980 --> 15:12.760 and indeed 307 15:12.760 --> 15:14.120 we've got that. 308 15:14.120 --> 15:16.720 So play around with these configurations. 309 15:16.720 --> 15:20.460 I think this is a great lab from start to finish to really practice all of 310 15:20.460 --> 15:21.640 these concepts. 311 15:21.640 --> 15:25.720 Wipe it out and once you're done with it and do it again from scratch and try 312 15:25.720 --> 15:26.560 to memorize 313 15:26.560 --> 15:30.910 all these commands and make sure you can do everything from start to finish and WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 313 15:26.560 --> 15:30.910 all these commands and make sure you can do everything from start to finish and 314 15:30.910 --> 15:31.280 build 315 15:31.280 --> 15:36.840 not only GRE tunnels but also different VRFs while building the GRE tunnels 316 15:36.840 --> 15:37.660 across those 317 15:37.660 --> 15:38.660 VRFs. 318 15:38.660 --> 15:41.260 I hope this has been informative for you and I'd like to thank you for viewing.