Range of Private IP address

10.0.0.0 to 10.255.255.255
169.254.0.0 to 169.254.255.255 (APIPA only)
172.16.0.0 to172.31.255.255
192.168.0.0 to 192.168.255.255

What is APIPA?

Stands for Automatic Private IP Addressing

A feature of Microsoft Windows, APIPA is a DHCP failover mechanism for local networks. With APIPA, DHCP clients can obtain IP addresses when DHCP servers are non-functional. APIPA exists in all modern versions of Windows except Windows NT.

When a DHCP server fails, APIPA allocates IP addresses in the private range 169.254.0.1 to 169.254.255.254. Clients verify their address is unique on the network using ARP. When the DHCP server is again able to service requests, clients update their addresses automatically.
In APIPA, all devices use the default network mask 255.255.0.0 and all reside on the same subnet.
APIPA is enabled on all DHCP clients in Windows unless the computer's Registry is modified to disable it. APIPA can be enabled on individual network adapters.

NOTE: APIPA is a feature generally only useful on home or other small intranet LANs.

Difference between ISL and 802.1Q

Following table lists the difference between ISL (Inter-Switch Link) and 802.1Q VLAN tagging methods:

Note: Please click on the above image to Enlarge

Difference between Distance Vector and Link State Routing Protocols

Following table lists the Difference between Distance Vector and Link State Routing Protocols:

Note: Please click on the above image to Enlarge

What is Area Boogie Router in OSPF?

In the above topology, router R1 is called as Area Boogie router. Note that still this router is the ABR (Area Border Router) only. Since in the above topology Area 7 is not directly connected with Backbone area, the special term "Area Boogie Router" is used to identify router R1.

   For more details please refer the following URL:

https://learningnetwork.cisco.com/thread/39055