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0:00:12
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The next IP service we have is the web cache
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0:00:15
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coordination protocol or WCCP
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0:00:19
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which is used to redirect web requests from the router
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0:00:23
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to a caching engine so that local copies of web pages
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0:00:29
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can be sent to the cache engine instead of to the
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0:00:31
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final destination.
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0:00:34
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So this is similar to what the Waas device does
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0:00:38
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the W, A, A, S
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0:00:40
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which is essentially just forward caching.
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0:00:44
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Now from the router's point of view this configuration is really
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0:00:47
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straightforward because the router's going to learn about the
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0:00:49
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caching engine dynamically once WCCP is configured.
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0:00:56
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So on the caching server itself we're going to specify who are
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0:00:59
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the routers that are doing the redirects. From the router
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0:01:03
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typically the only thing we need to do is specify on what particular
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0:01:06
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interfaces we are going to redirect the traffic.
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0:01:11
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So configuration wise, we enable the feature globally
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0:01:14
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ip wccp web-cache
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0:01:18
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then at the link level we will say when web requests
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0:01:21
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are going either out the interface or coming in.
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0:01:26
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We can choose to redirect them to the cache engine.
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0:01:30
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So the difference between the inbound and outbound
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0:01:33
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is going to be similar to how the content based access control
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0:01:36
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could do the inspection either in or out.
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0:01:41
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So if we were to have a case where Router 1 has
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0:01:44
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multiple LAN interfaces
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0:01:46
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where we have Fast Ethernet 0/0
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0:01:49
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and Fast Ethernet 0/1
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0:01:53
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then we have a WAN interface that's going to the outside network.
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0:01:58
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If I were to match the redirects out
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0:02:01
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the serial, this would then be the same as doing the
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0:02:07
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redirects in on both of the LAN interfaces.
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0:02:12
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But if I wanted to do redirects from just one of the LAN interfaces
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0:02:16
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inbound, I would specify the redirection in here as opposed
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0:02:21
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to out the serial.
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0:02:25
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But in the case where there's only two interfaces, if there's one
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0:02:29
|
LAN interface and one WAN interface
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0:02:32
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then redirecting out the WAN is going to be the same as
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0:02:35
|
redirecting in on the LAN.
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0:02:38
|
Now for features like this again, the key is going to be to
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|
0:02:42
|
know where this is located in the documentation.
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0:02:46
|
If for some reason you did not know where features like
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0:02:48
|
this are located, that's again where you can work backwards
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0:02:52
|
from the master index.
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|
0:02:55
|
So if we knew for example that the command is going to start with
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|
0:02:57
|
wccp, but we don't know exactly where it's located
|
|
0:03:02
|
if we were to start at the main documentation page
|
|
0:03:07
|
let's say go to products, IOS
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|
0:03:11
|
regular IOS
|
|
0:03:12
|
12.4, 12.4 T
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|
0:03:17
|
then to release and general information
|
|
0:03:20
|
and to master index.
|
|
0:03:23
|
So I want all of the commands for 12.4 T
|
|
0:03:27
|
Since I know this is going to be related to ip wccp
|
|
0:03:32
|
this will be I through J
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|
0:03:33
|
if I search for wccp
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|
0:03:37
|
this says IAP
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|
0:03:40
|
which I believe is going to be IP application services.
|
|
0:03:47
|
So since now it's redirecting me to the IP application services
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|
0:03:50
|
command reference, I would then know from the configuration
|
|
0:03:54
|
guide point of view
|
|
0:03:56
|
it's going to be under that same document, so configuring
|
|
0:04:00
|
IP application services
|
|
0:04:02
|
configuring WCCP
|
|
0:04:04
|
So there are some other minor options that you can
|
|
0:04:07
|
change with this, but again if you look at the configuration
|
|
0:04:11
|
examples for this, it says either I could run
|
|
0:04:15
|
version 1 or version 2
|
|
0:04:19
|
so ultimately that's going to be based on what the
|
|
0:04:22
|
caching engine itself supports
|
|
0:04:26
|
we could also be using a multicast address for the redirection
|
|
0:04:31
|
we could do authentication
|
|
0:04:36
|
but again, for the majority of these documents if you look at
|
|
0:04:38
|
simply where it says how to configure, then you'll
|
|
0:04:42
|
see the step by step task list
|
|
0:04:45
|
it says you need to configure WCCP, the rest of everything
|
|
0:04:49
|
else is going to be optional, so the minimum config would be
|
|
0:04:52
|
to turn on WCCP
|
|
0:04:56
|
so this is specifying the version, this is turning it on globally
|
|
0:05:00
|
then at the link level we're redirecting either the inbound
|
|
0:05:04
|
requests or the outbound requests.
|
|
0:05:07
|
So again overall for these type of services, they're not going to
|
|
0:05:11
|
expect you to be an expert in this in the exam.
|
|
0:05:14
|
As long as you know where these are located in the documentation
|
|
0:05:16
|
under the configuring IP services and the configuring IP
|
|
0:05:21
|
addressing, make sure you spend some time reading through
|
|
0:05:24
|
those so you can figure out what are the features to
|
|
0:05:26
|
begin with. Additionally, if you explore the context
|
|
0:05:30
|
sensitive help, so in global config look at the ip ?
|
|
0:05:33
|
at the interface look at the ip ?
|
|
0:05:36
|
For any commands that you don't know what they do
|
|
0:05:38
|
spend a few minutes to reference those in the command
|
|
0:05:41
|
reference, then you'll know where that's located in the
|
|
0:05:45
|
configuration guide and you can figure out what's the
|
|
0:05:48
|
step by step task list I need to do in order to implement
|
|
0:05:51
|
this particular technology.
|
