.TH TCP_SCAN 1.SH NAMEtcp_scan, udp_scan \- internet port scanners.SH SYNOPSIS.B tcp_scan[options] host service(s)....sp.B udp_scan[options] host service(s)....SH DESCRIPTIONThese commands take a list of internet services and investigate whichservices are available from a given host.  The \fItcp_scan\fR commandlooks for connection-oriented services; \fIudp_scan\fR identifiesactive datagram ports..spEach \fIservice\fR argument may be specified as a symbolic name(telnet), a port number (23), an interval (1-1023, telnet-smtp) or aninterval with the lower or upper bounds missing (the default bounds are1 and 65535, respectively)..spOptions:.IP -aReport status of all specified services..IP "-b (tcp_scan only)"Report banner information. Banners are converted to printable formusing C-like escape sequences. Whenever \fItcp_scan\fR finds that theserver does telnet options negotiation it sets the 't' flag in theoutput.  This is useful to detect telnet servers on non-standard ports..IP "-l load"Minimize the impact of network roundtrip delays by performing\fIload\fR network probes in parallel. The default load is theper-process open-file limit - 10..IP "-p port (udp_scan only)"Use this port to verify that the host or network is alive. By defaultthe UDP port scanner uses port number 1. Specify a port number that isknown to be unreachable or inactive..IP "-s string (tcp_scan only)"After a connection has been established, send.I stringto the server. The following backslash escapes can be used:  \\ooo(octal character code), \\b (backspace), \\f (formfeed), \\n (newline),\\r (carriage-return), \\s (space), and \\t (horizontal tab). The.I stringshould be enclosed between quotes if it contains shell meta characters..IP "-S source_port"Use the specified source port, instead of an arbitrary one.Examples: "tcp_scan -S ftp-data", or "udp_scan -S domain"..IP "-t time (tcp_scan only)"Give up when the program has not found out anything within.I timeseconds. This bounds the time lost when scanning systems with brokenTCP/IP implementations that do not send RESETs when contacted at a deadport.  The udp scanner already has a built-in mechanism to detect deadhosts..IP -uReport probes that fail with "Host unreachable". Use this with packetfilters that pass most traffic..IP -UReport probes that do \fInot\fR fail with "Host unreachable". Use thiswith packet filters that block most traffic..IP "-w time (tcp_scan only)"Wait for at most \fItime\fR seconds for banner information..SH WARNINGThese programs will raise lots of alarms on sites that run the \fItcpwrapper\fR or other network logging software. Use only with priorpermission..SH BUGSThe UDP port scanner relies on ICMP replies to detect that a service isunavailable, and may report false positives when the host or networkdies in the middle of a measurement..PPThe TCP port scanner does not keep track of roundtrip times orof retransmissions, and may overload hosts or networks..PPWith some UNIX implementations, a single "Host unreachable" conditionaffects all connections that are being established with that host..PPWith some UNIX implementations, a single "Host unreachable" conditionaffects all TCP connections to that host, even those that alreadyexist..SH AUTHORWietse Venema