Connectivity Troubleshooting Flashcards
1
Q
Ping
A
Test two-way connection between endpoints
ICMP protocol
!!!!! = Successful
….. = No route to destination, or IP didn’t respond
UUUUU = Unreachable (Packet was discarded - potentially by ACL)
2
Q
Extended Ping
A
Allows you to specify extra parameters for the ping
(Source address, destination address, datagram size, repeat count, etc)
Command: ping
3
Q
Traceroute
A
Shows you the path taken to a destination
Has a TTL
Can help find which networking device in a network is causing an issue
4
Q
Layer 1 Troubleshooting Commands
A
show ip interface brief
show interface
5
Q
Layer 2 Troubleshooting Commands
A
show mac address-table dynamic
clear mac address-table dynamic
show arp
6
Q
Layer 4 Troubleshooting Tool
A
Telnet
7
Q
DNS Troubleshooting
A
nslookup
ping by FQDN
