Monday, September 8, 2008

MULTIPLE NETWORK LAYER SUPPORT

  • Eigrp supports IP, APPLETALK and Novell Netware Internet packet exchange(IPX) through the use of PROTOCOL DEPENDANT MODULES
SEAMLESS CONNECTIVITY ACROSS ALL DATA LINK LAYER PROTOCOLS AND TOPOLOGIES
  • Eigrp does not require any special configuration to work across Layer2 Protocols
  • ospf uses different configuration for different Layer2 Protocols , such as Ethernet and Frame-relay
SOPHISTICATED METRIC
  • Eigrp represent values in 32 bit format for additional granularity
In 2 of the key technologies out of 4 interesting
  1. Neighbor discovery / recovery
  2. Reliable Transport Protocol RTP
  3. DUAL finite state machine
  4. Protocol Dependant Modules (PDM'S)
Reliable Transport Protocol aka RTP:
  • Guaranteed ordered delivery of EIGRP packets .
  • Intermixed transmission of Multicast and Unicast Packets
Protocol Dependant Modules aka PDM'S:
  • Responsible for network layer Protocol Specific requirements
Interesting Example:
  • IP Eigrp module is responsible for sending and receiving eigrp pakects that are encapsulated in IP
  • The ip-eigrp also responsible for parsing Eigrp Packets and informing DUAL of the new Information received
  • Ip-eigrp asks Dual to make routing decisions , the results ofwhich are stored in ip routing table
  • Ip-eigrp is responsible for re-distributing routes learned by other ip routing protocols
FEW OF THE DEFINITIONS WHICH LOOKS EASY HERE:
  • AD = cost of next hop router and destination
  • FD = cost from local router + cost between Local router and next hop router
these two i found more apt and easy way to understand than ad and fd in cbt

THE RECOMPUTATION:

  • A Recomputation occurs when destination has no Feasible Successor
  • Recomputation is the way to determine new successor when feasible successor are absent
  • Recomputation is not processor intensive
  • Its always better to avoid Re-Computation
  • In the process , if the neighbor router has a route for destination , it sends a reply packet
  • If it does not have a router it sends QUERY packet
  • While the destination in active state , a router cannot change the Destination routing table information
these were some of the points which i found new .


catch you with more of the updates

regards
rakesh

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