Wednesday, July 24, 2013

Essential Network Troubleshooting Commands


arp -a Shows gateway MAC address.
 gpresult Starts the Operating System Group Policy Result tool
 ipconfig /all Displays the full TCP/IP configuration for all adapters
 ipconfig /flushdns Flushes the DNS resolver cache. Helpful when troubleshooting DNS name resolution problems
 nbtstat -a <MachineName> Obtains info from WINS or LMHOST (discovers who is logged on)
 nbtstst -A <IP> Gets info from WINS or LMHOST (discovers who is logged on)
 nbtstat -R Purges and reloads the remote cache name table
 nbtstat -n Lists local NetBIOS names.
 nbtstat -r Useful for detecting errors when browsing WINS or NetBIOS
 netstat -ab The b switch links each used port with its application
 netstat -an Shows open ports
 netstat -an 1 | find "15868" Locates only lines with the number 15868 and redisplays every one second
 netstat -an | find"LISTENING"     Shows open ports with LISTENING status
 net use  Retrieves a list of network connections
 net use file://1.2.3.4/ Sees if the machine can poll IP 1.2.3.4
 net user Shows user account for the computer
 net user /domain Displays user accounts for the domain
 net user /domain <UserName> Shows account details for specific user
 net group /domain Shows group accounts for the domain
 net view Displays domains in the network
 net view /domain Specifies computers available in a specific domain
 net view /domain: <DomainName> | more Shows user accounts from specific domain
 net view /cache  Shows workstation names
 nslookup Looks up IP/hostnames and displays information helpful in diagnosing DNS issues
 ping -a <IP> Resolves IP to Hostname
 ping -t <IP> Pings host until stopped
 set U Shows which user is logged on
 set L Shows the logon server
 telnet <IP> <port> Confirms whether the port is open
net use %LOGONSERVER%       Use this command to hit the Domain Controller resulting in DC Agent                                                              picking up the user name you logged onto the server with.