Router Commands

Router Processes & Statistics

sh processes	shows active processes running on router
sh process cpu	shows cpu statistics
sh mem	shows memory statistics
sh flash	the flash memory and displays the size of files and the amount of free flash memory
sh buffers	displays statistics for router buffer pools; shows the size of the Small, Middle, Big, Very Big, Large and Huge Buffers
sh stacks	shows reason for last reboot, monitors the stack use of processes and interrupts routines

IP Commands

Configure IP on an interface:
int serial 0
ip address 157.89.1.3 255.255.0.0
int eth 0
ip address 2008.1.1.4 255.255.255.0

Other IP Commands:

sh ip route	view ip routing table
ip route <remote_network> <mask> <default_gateway> [administrative_distance]	configure a static IP route
ip route 0.0.0.0 0.0.0.0 <put gateway of the last resort here>	sets default gateway
ip classless	use with static routing to allow packets destined for unrecognized subnets to use the best possible route
sh arp	view arp cache; shows MAC address of connected routers
ip address 2.2.2.2 255.255.255.0 secondary	configure a 2nd ip address on an interface sh ip protocol

CDP Commands (Cisco Discovery Protocol uses layer 2 multicast over a SNAP-capable link to send data):

sh cdp neighbor	shows directly connected neighbors
sh cdp int	shows which interfaces are running CDP
sh cdp int eth 0/0	show CDP info for specific interface
sh cdp entry <cdp neighbor here>	shows CDP neighbor detail
cdp timer 120	change how often CDP info is sent (default cdp timer is 60)
cp holdtime 240	how long to wait before removing a CDP neighbor (default CDP holdtime is 180)
sh cdp run	shows if CDP turned on
no cdp run	turns off CDP for entire router (global config)
no cdp enable	turns off CDP on specific interface