Midterm Flashcards
Network Characteristics
Topology, Speed, Cost, Security, Availability, Scalability, Reliability
Components of a Network Capable Device
CPU, Operating System, Memory and Storage
Process Switching
Packets are forwarded to the control panel where the CPU decides where to forward the packet
Fast Switching
A fast switching cache is used to store next-hop information. If a packet is going to a destination with info in the cache the next-hop info in the cache is used without CPU intervention
Cisco Express Forwarding (CEF)
CEF uses a Forwarding Information Base that is change-triggered. It is the fastest forwarding method and preferred choice on Cisco routers
Best Path
Selected by a routing protocol based on the value/metric it uses to determine the distance to reach a network. It is the path with the lowest metric
Metric
Value used to measure distance to a network
Dynamic routing protocol metrics
RIP - hop count
OSPF - Cost (cumulative bandwidth fr source to dest.)
EIGRP - Bandwidth, delay, load, reliability
Load Balancing
When a router has two or more paths with equal cost metrics, packets are forwarded using all paths equally
Administrative Distance
If multiple paths to the same dest. are configured on the same router, the one in the route table is the one with the lowest AD. The lower AD, the more reliable
Routing Table
Stored in RAM, contains info about direct connected and remote routes
What does OSPF stand for?
Open Shortest Path First
What does EIGRP stand for?
Enhanced Interior Gateway Routing Protocol
What does RIP stand for?
Routing Information Protocol
What does IS-IS stand for?
Intermediate System-to-Intermediate System
IPv6 Dynamic Routing Protocols
OSPFv3, RIPng (next gen), EIGRP for IPv6
IPv6 Static Route Next Hop Options
Next hop: only ip specified
Direct: only exit interface specified
Fully specified: ip and exit interface specified
IGP
Interior gateway protocol: routing within an AS; includes RIP, OSPF, IS-IS
EGP
Exterior gateway protocol: routing between AS; BGP is the official protocol used by internet
Distance Vector Routing Protocols
Use distance (hop count/#of routers) and direction (which interface)
Link-State Routing Protocols
Use sophisticated algorithm (SPF) and simple metrics (bandwidth) to calculate best path
Why passive interfaces?
Because unneeded updates are waste of bandwidth, resources and security risk