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0:00:12
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Our final feature here in bridging
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is the Fall Back Bridging feature,
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which is a combination of routing and bridging at
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Now, the 3560 platforms supports
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Any other protocols that it learns,
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So, if you're running legacy IPX or NetBIOS, that stuff
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0:00:47
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So, if we had two hosts that we're running
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they would be able to see each other only if they
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If the devices were in different
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because normally, to move between different
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The Fall Back Bridging feature
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is kind of a hack in this process that allows
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but bridge other legacy protocol stacks
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0:01:27
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So, if we have a switch virtual
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and a routed interface that has
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then, we're able to move legacy
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0:01:41
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The configuration of this is fairly
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where we say, Bridge 1
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So, we're defining a
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This is not running
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because the switch is already running IEEE
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So here, we're saying, Bridge 1
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0:02:05
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Then, on the switch virtual interfaces,
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this is where we apply the bridge group.
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0:02:15
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So, the design that this would have...
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would be that if switch 1 had...
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VLAN 10...
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and VLAN 20.
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And in VLAN 20, we had hosts
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In VLAN 20, we had 10.0.0.0/24.
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This would then mean, if a host in
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the traffic would have to be routed.
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It would go up to the switch
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it would route over to the switch virtual interface
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0:03:02
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So, the key is here between these two interfaces,
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It's changing out the source MAC address
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to the MAC address of
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So, normal routing logic, that is, we move traffic between
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0:03:25
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Now, with the Fall Back Bridging feature,
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it would be valid to have
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And the IPX network A over here
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where a traffic between the
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0:03:54
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Now, there's really no way that we could test this without
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0:04:00
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And I don't believe
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have those in there anymore.
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IPX Routing, oh actually,
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So, we may actually be able to do this.
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0:04:24
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Let's look at our physical topology.
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0:04:32
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Right now, router 4 and 6
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are in two separate VLANs. They're in VLAN 20
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So, router 4 is in 20. Router 6 is in 30.
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0:04:51
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They are in separate IPv4 networks, because they're in
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0:05:02
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Let's see now, do router 4 and 6 support the...
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the IPX process?
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0:05:11
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Let's say, IPX Routing 1.1.1.1, or 1.1.1.
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0:05:22
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Then, let's see if I remember this syntax.
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0:05:26
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IPX Address? No.
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It's the IPX Network.
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Right?
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IPX Network is A.
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0:05:42
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Then on...
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router 6, we would say the same thing.
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0:05:48
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IPX Routing...
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0:05:54
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1.1.1.
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Then on the LAN interface,
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0:06:01
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IPX Network A.
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0:06:04
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So, when we look at the two links
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0:06:06
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between the routers, one of them
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0:06:11
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One of them is in the 30
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0:06:15
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So, this means that the switch that is
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0:06:20
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would normally have interface VLAN 20
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0:06:26
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We'll say 20.0.0.254.
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0:06:31
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Then, it would have interface VLAN 30
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0:06:35
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with IP address 30.0.0.254.
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0:06:43
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If we configure basic
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0:06:47
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we could say, on router 6
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0:06:52
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use my gateway 30.0.
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0:06:57
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30.0.0.254."
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0:07:00
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Router 4 would then say the opposite
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0:07:07
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go to 20.0.0.254."
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0:07:11
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So now, I should be
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0:07:28
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Okay, let's see, can we
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0:07:34
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Okay, we can reach the switch.
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0:07:38
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Router 6 likewise should be able to reach the
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0:07:45
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Then, can we reach the other SVI, 20.0.0.254?
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0:08:02
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router 4. So, we're able
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0:08:06
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VLAN, but not down to 4,
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0:08:14
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4. Let's see, can we ping 30...
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0:08:19
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0.0.254?
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0:08:22
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We can.
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0:08:25
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Ugh, that's kind of odd.
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0:08:26
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Let's look at the routing table.
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0:08:35
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So, it says, "The 30
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0:08:42
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and on router 6,
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0:08:47
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It says, "The 20
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0:08:50
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Let's try this. Let's...
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0:08:52
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send multiple packets,
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0:08:56
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and on router 4, let's see if they are
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0:09:01
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And Debug IP ICMP.
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0:09:10
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4 is not receiving these packets.
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0:09:16
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If 4 is not receiving them,
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0:09:19
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then, it most likely means that the
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0:09:22
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Switch 4 is not forwarding them on.
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0:09:27
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So, why would the switch
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0:09:31
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router 4 and router 6?
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0:09:34
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If the switch virtual interfaces
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0:09:38
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I was on... And let me... Let's make a separate
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0:09:47
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So, switch 4 has...
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0:09:50
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VLAN 10.
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0:09:54
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That is 10... Or not VLAN 10, VLAN 20.
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0:09:57
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20. That is 20.0.0.254.
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0:10:03
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In this segment, we have router 4, 20.0.0.4.
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0:10:08
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We have VLAN 30. That is 30.0.0.254.
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0:10:15
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And router 6, 30.0.0.6.
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0:10:21
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So, what's happening now is
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0:10:27
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4 can reach VLAN 30,
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0:10:32
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6 can reach VLAN 30,
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0:10:38
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but they can't reach each other.
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0:10:43
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So, this is telling us at least that on 4 and 6,
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0:10:49
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Because if their route were wrong, 4 would
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0:10:56
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So, what are we missing then?
|
|
0:11:00
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that is not a default
|
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0:11:07
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The switch is not routing by default.
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|
0:11:10
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So, we need to tell it that if we're gonna
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|
0:11:16
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we need to enable that. So, the switch is
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|
0:11:21
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by default unless we turn routing on.
|
|
0:11:26
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So, it can be a frustrating
|
|
0:11:31
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to look at this where it's just
|
|
0:11:36
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but that's gonna stop the
|
|
0:11:40
|
So, I want to ping 30.0.0.6.
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|
0:11:46
|
So, routing between
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0:11:49
|
Now, for the Fall Back Bridging,
|
|
0:11:52
|
I should be able to create the
|
|
0:11:59
|
Then on, VLAN 20, put this is
|
|
0:12:08
|
And if we look at router 4
|
|
0:12:18
|
here is the address of router 4.
|
|
0:12:22
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So, it's the IPX network
|
|
0:12:24
|
If I were to go to 6,
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|
0:12:27
|
and ping this address,
|
|
0:12:33
|
if this works, then, it's gonna tell us that switch 4
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|
0:12:49
|
Which it is.
|
|
0:12:52
|
Because if we look at
|
|
0:12:57
|
Show IPX Route for that destination.
|
|
0:13:00
|
Or no, we can't say that.
|
|
0:13:04
|
There's only one connected
|
|
0:13:09
|
So, it means that the traffic
|
|
0:13:13
|
But we could see the configuration on
|
|
0:13:18
|
Just we define the bridge group.
|
|
0:13:20
|
It's using the VLAN bridge, it's not using
|
|
0:13:25
|
Then, we're applying it at
|
|
0:13:30
|
or a native Layer 3 routed interface, which is something
|
|
0:13:39
|
Under the documentation,
|
|
0:13:41
|
this would be in the Switching
|
|
0:13:49
|
Then, under Configuring
|
|
0:13:56
|
Monitoring and maintaining, we can
|
|
0:14:02
|
So, basically, the same thing
|
|
0:14:05
|
Let's say, Show Bridge 1 Group.
|
|
0:14:09
|
And Show Bridge 1,
|
|
0:14:13
|
these are the MAC address for the IPX
|