DOS Commands
Below are some handy dos command to help diagnose networking issues.
Quick Links
Ping Tracert Finger Nslookup Telnet Net stat SFC
Ping [top] | |
Format | ping www.domainname.com or ping xxx.xxx.xxx.xxx(x = ip number) |
Usage | ping [-t] [-a] [-n count] [-l size] [-f] [-i TTL] [-v TOS] [-r count] [-s count] [[-j host-list] | [-k host-list]][-w timeout] destination-list |
Options | -t Ping the specified host until stopped. To see statistics and continue – type Control-Break; To stop – type Control-C. -a Resolve addresses to hostnames. -n count Number of echo requests to send. -l size Send buffer size. -f Set Don’t Fragment flag in packet. -i TTL Time To Live. -v TOS Type Of Service. -r count Record route for count hops. -s count Timestamp for count hops. -j host-list Loose source route along host-list. -k host-list Strict source route along host-list. -w timeout Timeout in milliseconds to wait for each reply. |
Tracert [top] | |
Format | tracert www.domainname.com or tracert xxx.xxx.xxx.xxx |
Usage | tracert [-d] [-h maximum_hops] [-j host-list] [-w timeout] target_name |
Options | -d Do not resolve addresses to hostnames. -h maximum_hops Maximum number of hops to search for target -j host-list Loose source route along host-list. -w timeout Wait timeout milliseconds for each reply. |
Finger [top] (note: not usually implement anymore) |
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Format | finger name@domain.com.au |
Usage | FINGER [-l] [user]@host […] |
Options | -l Displays information in long list format. user Specifies the user you want information about. Omit the user parameter to display information about all users on the specified host. @host Specifies the server on the remote system whose users you want information about. |
Nslookup [top] | |
Format | nslookup |
Usage | nslookup |
Options | (identifiers are shown in uppercase, [] means optional) NAME – print info about the host/domain NAME using default server NAME1 NAME2 – as above, but use NAME2 as server help or ? – print info on common commands set OPTION – set an option all – print options, current server and host [no]debug – print debugging information [no]d2 – print exhaustive debugging information [no]defname – append domain name to each query [no]recurse – ask for recursive answer to query [no]search – use domain search list [no]vc – always use a virtual circuit domain=NAME – set default domain name to NAME srchlist=N1[/N2/…/N6] – set domain to N1 and search list to N1,N2, etc. root=NAME – set root server to NAME retry=X – set number of retries to X timeout=X – set initial time-out interval to X seconds type=X – set query type (ex. A,ANY,CNAME,MX,NS,PTR,SOA,SRV) querytype=X – same as type class=X – set query class (ex. IN (Internet), ANY) [no]msxfr – use MS fast zone transfer ixfrver=X – current version to use in IXFR transfer request server NAME – set default server to NAME, using current default server lserver NAME – set default server to NAME, using initial server finger [USER] – finger the optional NAME at the current default host root – set current default server to the root ls [opt] DOMAIN [> FILE] – list addresses in DOMAIN (optional: output to FILE) -a – list canonical names and aliases -d – list all records -t TYPE – list records of the given type (e.g. A,CNAME,MX,NS,PTR etc.) view FILE – sort an ‘ls’ output file and view it with pg exit – exit the program |
Telnet [top] | |
Format | telnet domain port |
Usage | telnet domain 25 or 110 |
Options | close close current connection display display operating parameters open connect to a site quit exit telnet set set options (type ‘set ?’ for a list) status print status information unset unset options (type ‘unset ?’ for a list) ?/help print help information
set options |
Netstat [top] | |
Format | |
Usage | NETSTAT [-a] [-e] [-n] [-s] [-p proto] [-r] [interval] |
Options | -a Displays all connections and listening ports. -e Displays Ethernet statistics. This may be combined with the -s option. -n Displays addresses and port numbers in numerical form. -p proto Shows connections for the protocol specified by proto; proto may be TCP or UDP. If used with the -s option to display per-protocol statistics, proto may be TCP, UDP, or IP. -r Displays the routing table. -s Displays per-protocol statistics. By default, statistics are shown for TCP, UDP and IP; the -p option may be used to specify a subset of the default. interval Redisplays selected statistics, pausing interval seconds between each display. Press CTRL+C to stop redisplaying statistics. If omitted, netstat will print the current configuration information once. |
System File Checker (SFC) [top] | |
Format | |
Usage | SFC [/SCANNOW] [/SCANONCE] [/SCANBOOT] [/CANCEL] [/ENABLE] [/PURGECACHE] [/CACHE SIZE=x] [/QUIET] |
Options | /SCANNOW Scans all protected system files immediately. /SCANONCE Scans all protected system files once at the next boot. /SCANBOOT Scans all protected system files at every boot. /CANCEL Cancels all pending scans of protected system files. /QUIET Replaces all incorrect file versions without prompting the user. /ENABLE Enables Windows File Protection for normal operation /PURGECACHE Purges the file cache and scans all protected system files immed iately. /CACHESIZE=x Sets the file cache size |