and Troubleshooting
You can use the ping and traceroute commands to test connectivity to remote devices, and
you can use both of them with many protocols, not just IP.
The debug command and the show processes command you need to troubleshoot a
router are listed in Table 2.13:
Using the ping Command
So far, you’ve seen many examples of pinging devices to test IP connectivity and name resolution
using the DNS server. To see all the different protocols that you can use with the ping
program, type ping ?, like so:
Corp#ping ?
WORD Ping destination address or hostname
clns CLNS echo
ip IP echo
srb srb echo
tag Tag encapsulated IP echo
The ping output displays the minimum, average, and maximum times it takes for a ping
packet to find a specified system and return. Here’s an example:
Corp#ping R1
Translating "R1"...domain server (192.168.0.70)[OK]
Type escape sequence to abort.
TABLE 2 . 1 3 Troubleshooting Commands
Command Meaning
ping Tells you whether a host on an internetwork has an IP stack enabled
traceroute Tells you the path a packet takes to find a remote host
debug Enables packet-level debugging used for troubleshooting a router or
network
undebug The undebug command will disable debugging output on the router
show processes Show the processes used on a router and CPU cycles