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A couple of other minor options
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before we proceed on to EIGRP.
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We have the feature
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which is similar to the OSPF
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where this was originally
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that we did not want to send
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if there were no changes in the topology.
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So, if we were routing over
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or some sort of analogue dial link that
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it doesn't make sense for RIP to constantl
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unless something actually
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So, this one single command,
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basically says that RIP will only send
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So, ideally, you would wanna
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because it is not a negotiated option.
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The next feature we have
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Which is a basic error-checking logic
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Everytime it receives an update message in,
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it looks at the source address
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Now, if the source of the packet happens to
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the receiving router is going to
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So, basic error-checking logic that says,
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they should not be routing
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Because ultimately, there would be some
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when they actually go and do a
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So, if they're not on the same subnet, normally,
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However, there are some
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for two routers to be in different
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mainly if we are running
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to install the remote neighbor's addresses.
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Now, the case that you run into this
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is that if you have two routers
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For example between router 4 and router 5,
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where the point-to-point link
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And it has addresses that are
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Now, in a case where we could do this if we
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So, even though we're in different subnets,
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PPP is not gonna care about this,
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because it's gonna do what for us
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So, we saw it previously when the
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what's part of that process that they do?
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They're gonna learn each
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and install this as a connected
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So this means that on router 4 and router 5,
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if we were to go to this link,
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serial 0/1/0, and remove the IP address,
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run PPP encapsulation,
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and say, "The IP address
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Or IP Unnumbered...
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to the loopback.
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And we do the same thing on router 4.
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So, this link has no IP address,
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or IP unnumbering to the loopback,
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and the encapsulation is PPP.
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We should see now once
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if we look at the
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we should see router 5 as a
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So, we should be able to reach
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we see there is reachability
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The problem now though,
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the RIP process will say that it's not
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from someone on this interface but
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0:05:24
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So, we are receiving the update. It says,
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and the update was installed."
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0:05:35
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What this means then is that the feature...
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that I'm trying to show here, it doesn't
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0:05:46
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So, instead of unnumbering it, let's
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And let's manually configure them
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Let's say that, router 4 is 4.4.4.4/31.
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And router 5...
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is 5.5.5.5.
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/31.
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Now again, this should
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because IPCP, as part of the PPP negotiation
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0:06:25
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but now, let's look at Debug IP RIP.
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and we're looking for the
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serial 0/1, which actually now
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because those are in different networks. So, under
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For router 5's link and for router 4's link.
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Then again, we'll Debug IP RIP.
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0:07:41
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So now, we see the error message. Router 4
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5.5.5.5 on the serial link,
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Because when the update is coming in,
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router 4 is checking against its own
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0:07:59
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These devices are not
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0:08:03
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So, even though technically in
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because PPP is solving the
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0:08:10
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The RIP process doesn't understand this.
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0:08:12
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This is where the no validate update
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0:08:19
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To say that in very specific cases like this,
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0:08:21
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where the routers are not on the same subnet
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0:08:27
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we should skip over the
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0:08:30
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and allow the updates to
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0:08:33
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But as we saw what the first
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0:08:37
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when the link is running unnumbered,
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0:08:39
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the router assumes that
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0:08:42
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So, the validation is automatically
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0:08:48
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So, in order to accept this update, what we
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and say on both ends,
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0:09:04
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So, on router 5, let's say the same
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0:09:08
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No.
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0:09:12
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Validate Update Source
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0:09:15
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Then, if we look at the
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0:09:26
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We see now, we can install updates
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0:09:34
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So, this is kind of an odd output
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0:09:38
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It says we received the update but we don't
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0:09:45
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This is the case that RIP is trying to
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0:09:49
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It's only based on the case that
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0:09:54
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because of the PPP host route
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0:09:59
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where...
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0:10:01
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actually not that dynamically learned one.
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0:10:08
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Let's say Show IP Route Connected.
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0:10:12
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Where we can properly
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0:10:16
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because we have the host route
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0:10:31
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So, features like this in RIP, this is what you're gonna
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0:10:36
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So, when we compare their protocol as a whole
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0:10:39
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to EIGRP or OSPF or BGP,
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|
0:10:42
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we'll see that there is much less funtionality
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0:10:46
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as to what you can configure and what the little
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|
0:10:51
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But again, there's no
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0:10:54
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without essentially knowing
|
|
0:11:00
|
So again, for the command reference, this would
|
|
0:11:06
|
If we go to products, IOS, Cisco IOS 12.4
|
|
0:11:14
|
12.4 T...
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|
0:11:16
|
Reference Guides...
|
|
0:11:18
|
Command Reference...
|
|
0:11:20
|
Then IP Routing RIP Command Reference.
|
|
0:11:31
|
So, some of these minor things like the...
|
|
0:11:36
|
output delay.
|
|
0:11:51
|
It says, "To change the inter-packet
|
|
0:11:54
|
use the output delay command in
|
|
0:11:58
|
It says, "The delay between the packets in a multiple
|
|
0:12:06
|
So, it means that if you
|
|
0:12:10
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that the RIP update is gonna have
|
|
0:12:14
|
then you can put a processing delay
|
|
0:12:18
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So, something like this, there's not really a lot
|
|
0:12:24
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It's not really a big design question.
|
|
0:12:26
|
It's just whether you understand that
|
|
0:12:30
|
So, for a lot of this stuff,
|
|
0:12:34
|
there's really no shortcut to it.
|
|
0:12:36
|
You simply need to spend the time to sit down
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|
0:12:40
|
to figure out what particular features
|