Skip to main content

CCNA4: Final Exam

Review Notes, v. 3.1
1.1.1 Private addressing



1.1.2 Major NAT and PAT features
Dynamic NAT is designed to map a private IP address to a public address. Any IP address from a pool of public IP addresses is assigned to a network host. Overloading, or Port Address Translation (PAT), maps multiple private IP addresses to a single public IP address. Multiple addresses can be mapped to a single address because each private address is tracked by a port number.
1.1.3 Configuring NAT and PAT
The access list must permit only those addresses that are to be translated. Remember that there is an implicit “deny all” at the end of each access list.

1.1.4 Configuring DHCP
- Typically, a DHCP server will be configured to assign much more than an IP address. Other IP configuration values such as the default gateway can be set from the DHCP configuration mode. Using the default-router command sets the default gateway.
- A default router must be defined for clients
2.1.1 WAN devices
- For digital lines, a channel service unit (CSU) and a data service unit (DSU) are required. The two are often combined into a single piece of equipment, called the CSU/DSU. The CSU/DSU may also be built into the interface card in the router.
- A modem is needed if the local loop is analog rather than digital.
- A router is commonly considered a DTE device.
2.1.2 WAN Standards
WANs use the OSI reference model, but focus mainly on Layer 1 and Layer 2.
2.2.1 ISDN
- Another common application of ISDN is to provide additional capacity as needed on a leased line connection.
- ISDN is also used as a backup in the case of a failure of the leased line.

I will post chapter 3,4 on wednesday. See you soon. if you like this post, you can bookmarks this site. and get up date.

Comments

Popular posts from this blog

Why is this Javascript much *slower* than its jQuery equivalent?

I have a HTML list of about 500 items and a "filter" box above it. I started by using jQuery to filter the list when I typed a letter (timing code added later): $('#filter').keyup( function() { var jqStart = (new Date).getTime(); var search = $(this).val().toLowerCase(); var $list = $('ul.ablist > li'); $list.each( function() { if ( $(this).text().toLowerCase().indexOf(search) === -1 ) $(this).hide(); else $(this).show(); } ); console.log('Time: ' + ((new Date).getTime() - jqStart)); } ); However, there was a couple of seconds delay after typing each letter (particularly the first letter). So I thought it may be slightly quicker if I used plain Javascript (I read recently that jQuery's each function is particularly slow). Here's my JS equivalent: document.getElementById('filter').addEventListener( 'keyup', function () { var jsStart = (new Date).getTime()...

Is it possible to have IF statement in an Echo statement in PHP

Thanks in advance. I did look at the other questions/answers that were similar and didn't find exactly what I was looking for. I'm trying to do this, am I on the right path? echo " <div id='tabs-".$match."'> <textarea id='".$match."' name='".$match."'>". if ($COLUMN_NAME === $match) { echo $FIELD_WITH_COLUMN_NAME; } else { } ."</textarea> <script type='text/javascript'> CKEDITOR.replace( '".$match."' ); </script> </div>"; I am getting the following error message in the browser: Parse error: syntax error, unexpected T_IF Please let me know if this is the right way to go about nesting an IF statement inside an echo. Thank you.