chp 1 routing concepts Flashcards
network characteristics
- topology
- speed
- cost
- security
- availability
- scalability
- reliability
router job
-routing traffic between networks
router components
- cpu
- memory and storage
- operating system
router memory
- ram (random access)
- rom (read only)
- nvram (non-volatile random access)
- flash
random access memory (ram)
- volatile
- runs ios
- running config
- ip routing and arp tables
- packet buffer
read only memory (rom)
- non volatile
- bootup instructions
- diagnostic software
- back up ios
non volatile random access memory (nvram)
- start up config
- non volatile
flash
- non volatile
- stores ios
- system related files
packet forwarding methods
- process switching
- fast switching
- cisco express forwarding (cef)
process switching
- every packet is processed by the cpu
- destination ip address
- route table entry
- exit interface
fast switching
- next hop is stored in cache
- first packet is processed by cpu
- other packets with the same destination are sent to cache not cpu
cisco express forwarding (cef)
- fastest
- packets are change triggered
- forward information base (fib) and adjacency table forward packets
- fib and adjacency table populated when routers learn of other routers
to have network access devices must have
- ip adress
- subnet mask
- default gateway
network documentation should include
- topology diagram
- addressing table
svi
- switch virtual interface
- used for management ip address
basic router settings
- name the device
- secure management access
- configure a banner
- save configuration
router interface must have
- ip address
- subnet mask
- not shutdown
- clock rate configured on serial cable end labeled dce
loopback interfaces
- logical
- internal to router
- not physical port
- automatically up
- useful for testing
- important to ospf routing
show commands
- verify operation
- configuration of interface
filter show commands
- | pipe character
- followed by perameter
packet forwarding process for directly connected interface
- arrives at interface
- searches routing table for match
- does destination ip match subnet of directly connected interface
- check arp cache and forward to host on local subnet
packet forwarding process for remote network and gateway of last resort
- arrives at interface
- searches routing table for match
- does destination ip match subnet of remote network/gateway of last resort
- encapsulate frame and forward out of exit interface to the next hop
best path
- chosen by routing protocol
- based on metric used to determine distance to reach a network
ipv4 dynamic routing protocols
- router information protocol (rip)
- open shortest path first (ospf)
- enhanced interior gateway routing protocol (eigrp)
- intermediate system to intermediate system (is-is)
rip metric
-hop count
ospf metric
-cumulative bandwidth
eigrp metric
- bandwidth
- delay
- load
- reliability
load balancing
- when a router has two or more path whose metrics are equal
- router forwards packets using both paths
- improves performance
administrative distance
- router value for best path
- 0 and up
- router with multiple paths to the same destination the path with lowest administrative distance is installed in routing table
routing table
- stored in ram
- directly connected routes
- remote routes
types of routes
- local route interfaces
- directly connected interfaces
- static routes
- dynamic routes
static routes
- configured manually
- define explicit path between two devices
- manually updated
- improved security
- improved control of resources
dynamic routing
- routers exchange info
- automatically populate routing tables
- creates converged network
ipv6 dynamic routing protocols
- ospfv3
- ripng (next generation)
- eigrp for ipv6
