Routing Flashcards
RIP
Routing Information Protocol
Dynamic routing protocol
Makes decisions based on hop count
OSPF
Open Shortest Path First
Dynamic routing protocol
Considers available bandwidth when making routing decisions
Convergence
Failing over from one route to a backup route
Routing Protocol
A protocol that advertises route information between routers
RIP, OSPF, EIGRP
Routed Protocol
A protocol with an addressing scheme that defines different network address.
IP
IGP
Interior Gateway Protocols
Operate within an autonomous system
EGP
Exterior Gateway Protocols
Operate between autonomous systems
AD
Administrative Distance
Index of believability
Lower AD values are more believable
Metric
Value assigned to a route
Lower metrics are better
Route Advertisement Methods
Distance Vector
Link State
Distance-Vector Routing Protocol
Sends full copy of routing table to directly attached neighbors
Sends full table periodically, even if nothing changed
Slow convergence
Split Horizon
Prevents route learned on one interface from being advertised out the same interface
Used to prevent routing loops on distance-vector protocols
Poison Reverse
Route received on one interface advertised back out same interface with metric considered to be infinite.
Used to prevent routing loops on distance-vector protocols
Link State Routing Protocol
Routers build topological map of network. Execute algorithm to calculate optimal path(s) to destination. Routers send updates when changes occur in network rather than repeatedly sending full routing information.
IS-IS
Intermediate System-to-Intermediate System
Dynamic, Link-state routing protocol
EIGRP
Enhanced Interior Gateway Routing Protocol
Route Redistribution
Multiple routing protocols on the same network can be used to update each other
NAT
Network Address Translation
Translates a private IP address into a publicly routable IP address.
DNAT
Dynamic NAT
Inside local addresses randomly assigned from a pool of addresses.
Many-to-many mapping
SNAT
Static NAT
Statically assign one routable address to a device.
Many-to-one mapping
PAT
Port Address Translation
Many inside local addresses share a single inside global address
IGMP
Internet Group Management Protocol
Multicast
PIM
Protocol Independent Multicast
Multicast
