21 - Wireless LAN - Frequencies and 802.11 Standards

Only short notes, as this is covered in the CCNA ...

NOTICE, that the extending your network you have your APs on DIFFERENT channels:

22 - Wireless LAN - Understanding the Hardware

awesome game that cisco wireless explorer! lol

23 - The Switches Domain - Additional Life-Saving Technology

etherchannel example
with loopguard, if x1 goes unidrection, it will detect a missed BPDU and disable the whole etherchannel
whereas with UDLD it will just pull out the bad link.

However loopguard does auto recover, will UDLD it is err-disabled so you need an admin to clear.
there is a err-disabled timeout you can configure  ... its a global thing, but its an option

vlan 10, stays within building B's floor, it doesn't go across distribution switches!

cisco say if you can design your network right, logically in blocks (keep it simple) it helps you

use all these technologies/features/best practices as they should be and it will be easy to implement these.

24 - Monitoring - Your Pulse on the Network

SLA (Service Level Assurance) Can also assign tracks to the sla monitors ..... (kept this brief as i use alot of snmp/syslog and IP SLA monitors at work) but these tracks can be assigned to static routes for example, so we can pull routes out of the table and the higher metric route can be used instead, when the ping/reachabilty comes back the tracker installs the route again (which is being tracked) and the higher metric static goes back out of the routing table - PRETTY SWEET

the SLA monitors do all sorts, from dhcp/dns/icmp/voice codes etc also can configure responsders (another router, for more accurate results ie the endpoint in the network)