WEBVTT 0:00:07.660000 --> 0:00:13.740000 All right, in this section, we're going to look at BGP over the next couple 0:00:13.740000 --> 0:00:17.740000 lessons here. We're going to start talking about BGP address families. 0:00:17.740000 --> 0:00:23.660000 Now, this is, of course, very similar to the way EIGRP handled this with 0:00:23.660000 --> 0:00:27.340000 different address families under EIGRP named mode. 0:00:27.340000 --> 0:00:31.820000 So, again, I'm sure you can see this is the trend of how things are headed. 0:00:31.820000 --> 0:00:35.980000 Just to introduce one more time, we've seen it quite a few times by now, 0:00:35.980000 --> 0:00:38.280000 but this is the topology we're going to use. 0:00:38.280000 --> 0:00:44.140000 And we're going to end up running BGP here, various different places. 0:00:44.140000 --> 0:00:48.460000 Generally, I have all the routers down at the bottom here set to be in 0:00:48.460000 --> 0:00:54.960000 BGP AS100, switch three up at the top in BGP AS300. 0:00:54.960000 --> 0:00:57.660000 That way we get some EGBGP up there. 0:00:57.660000 --> 0:01:01.580000 We may end up bringing some IGBGP in at the bottom, but this doesn't mean 0:01:01.580000 --> 0:01:09.240000 we're going to be running IGBGP on all of the routers by any means. 0:01:09.240000 --> 0:01:16.620000 So we're going to start just with doing the basics, IPv6 over IPv6. 0:01:16.620000 --> 0:01:17.840000 And let's move forward here. 0:01:17.840000 --> 0:01:20.200000 And I'll tell you what I mean by that. 0:01:20.200000 --> 0:01:27.180000 Okay. So with IPv6 and BGP, and if you're familiar with BGP with MPLS 0:01:27.180000 --> 0:01:31.880000 and so on, we have this idea of different address families. 0:01:31.880000 --> 0:01:37.820000 And like you've already seen, we're introducing this to OSPF, to EIGRP, 0:01:37.820000 --> 0:01:45.140000 RIP has it mostly for supporting VRFs on those protocols, but also for 0:01:45.140000 --> 0:01:48.560000 IPv6 and other protocols. 0:01:48.560000 --> 0:01:54.280000 With BGP, of course, we have VPNV4 address family, VPNV6, which we'll 0:01:54.280000 --> 0:01:59.480000 get to in our tunneling and when we do MPLS section. 0:01:59.480000 --> 0:02:02.700000 So this is going to just be a new address family. 0:02:02.700000 --> 0:02:05.740000 And as I just sort of alluded to, there's a couple of them. 0:02:05.740000 --> 0:02:13.360000 There's regular just IPv6 and then there's VPNV6 as well, as well as, 0:02:13.360000 --> 0:02:16.900000 of course, multicast for BGP. 0:02:16.900000 --> 0:02:22.260000 Okay. Now, here's the interesting thing about BGP, where I'm having a 0:02:22.260000 --> 0:02:26.060000 separate discussion on this that we didn't really have for the other routing 0:02:26.060000 --> 0:02:39.380000 protocols, is that BGP, the actual underlying IPv4 or IPv6, and then you 0:02:39.380000 --> 0:02:42.840000 can exchange whatever address family you want over that. 0:02:42.840000 --> 0:02:48.420000 So the transport that BGP is running on top of is separate from the address 0:02:48.420000 --> 0:02:52.660000 families being advertised in that session. 0:02:52.660000 --> 0:02:57.360000 Now where the problem comes in is you may have to deal with some next 0:02:57.360000 --> 0:03:01.760000 hop issues. And we're going to see this in the examples as we go through 0:03:01.760000 --> 0:03:09.700000 the configuration here, in that if you have an IPv6 session and then you 0:03:09.700000 --> 0:03:16.940000 run IPv4 over that, exchange IPv4 routes over an IPv6 session, what would 0:03:16.940000 --> 0:03:18.520000 the next hop be? 0:03:18.520000 --> 0:03:23.060000 It can't be an IPv6 address and that's all BGP knows. 0:03:23.060000 --> 0:03:28.780000 He knows, okay, I'm paired up with this IPv6 neighbor, but then what do 0:03:28.780000 --> 0:03:30.420000 I set the next hop to? 0:03:30.420000 --> 0:03:33.980000 And in some cases, as we're going to see, there is a little procedure 0:03:33.980000 --> 0:03:35.780000 that the router goes through. 0:03:35.780000 --> 0:03:39.100000 It will pick something to use. 0:03:39.100000 --> 0:03:44.620000 The only question is, what it picks to use, is that going to be used a 0:03:44.620000 --> 0:03:48.900000 bowl, or is that going to be a problem, and we're going to have to adjust 0:03:48.900000 --> 0:03:53.260000 this and change what we're doing for the next hop. 0:03:53.260000 --> 0:03:56.440000 And that's part of the problems we'll see as we get into the configuration. 0:03:56.440000 --> 0:04:02.040000 So, we're going to go through and we're going to do pretty much all the 0:04:02.040000 --> 0:04:07.940000 combinations. The only one I'm not going to look at here is IPv4 session 0:04:07.940000 --> 0:04:15.020000 with IPv4 routes over it, although, given the combination of things we're 0:04:15.020000 --> 0:04:20.600000 going to do, that may end up happening sort of accidentally anyway. 0:04:20.600000 --> 0:04:25.220000 Since IPv4 is the default address family in BGP, and I'm not going to 0:04:25.220000 --> 0:04:29.420000 bother with going through all the procedures, well, that's not all that 0:04:29.420000 --> 0:04:32.540000 procedures, just one command, but I'm not going to go through turning 0:04:32.540000 --> 0:04:41.020000 that off. So as we do, turn up an IPv4 session to support IPv6, we'll 0:04:41.020000 --> 0:04:44.680000 probably accidentally get some IPv4 routes through as well, since we will 0:04:44.680000 --> 0:04:45.820000 be injecting some. 0:04:45.820000 --> 0:04:50.220000 So, we'll pretty much see all the possible combinations here. 0:04:50.220000 --> 0:04:54.960000 The main focus, of course, the one we'll start with is going to be IPv6 0:04:54.960000 --> 0:05:00.240000 over IPv6. But as you've already seen with all of our other protocols, 0:05:00.240000 --> 0:05:07.360000 if you're already familiar with BGP, OSPF, EIGRP, RIP, and again, our 0:05:07.360000 --> 0:05:16.580000 purpose in this course is not to teach you this is going to be very, very 0:05:16.580000 --> 0:05:21.460000 similar and along the same lines as what we've seen so far, meaning that 0:05:21.460000 --> 0:05:27.020000 it's the same configure used to with a couple little twists on it we got 0:05:27.020000 --> 0:05:34.300000 to watch for. So we're going to do, like I said, IPv6 over an IPv6 session. 0:05:34.300000 --> 0:05:40.620000 We'll exchange IPv6 routes over an IPv4 session, and then we'll move on 0:05:40.620000 --> 0:05:47.760000 and do an IPv4 route coming over an IPv6 session. 0:05:47.760000 --> 0:05:52.500000 Not necessarily in that order as far as lessons go, but we'll be doing 0:05:52.500000 --> 0:05:55.340000 all of those combinations moving forward.