filed in CCNA, CCNP, Cisco IOS on Mar.19, 2009
Cisco IOS (originally Internetwork Operating System) is the software used on the Cisco Systems routers and all current Cisco network switches.
IOS is a package of routing, switching, internetworking and telecommunications functions tightly integrated with a multitasking operating system.
filed in CCNA, CCNP on Mar.18, 2009
OSPF Packets:
OSPFv3 has five types of packets: hello, DD, LSR, LSU, and LSAck.
OSPF does not use UDP or TCP for transmitting its packets. Instead, it runs directly over IP (IP protocol 89) using an OSPF header. One field in this header identifies the type of packet being carried.
Hello—Identifies neighbors and serves as a keepalive and [...]
filed in CCNA, CCNP on Mar.17, 2009
LSA 1 (Router LSA):
Generated by all routers in an area to describe their directly attached links (Intra-area routes). Flooded only within the area.
LSA 2 (Network LSA):Generated by the DR of a broadcast or Nonbroadcast segment to describe the neighbors connected to the segment. Flooded only within the area.
LSA 3 (Summary LSA):
Generated by the ABR to [...]
filed in CCNA, CCNP on Mar.16, 2009
In OSPF, a single AS can be divided into smaller groups called areas.An area is a set of networks and hosts within an AS that have been administratively grouped together.
Areas are logical groupings of hosts and networks, including their routers having interfaces connected to any of the included networks. Each area maintains a separate link [...]
filed in CCNA, CCNP on Mar.15, 2009
The cost (also called metric) of an interface in OSPF is an indication of the overhead required to send packets across a certain interface.Open Shortest Path First (OSPF) uses cost as the metric calculated, based on the bandwidth of the link. The cost of a link is calculated by dividing the reference bandwidth (100 Mbps [...]