.TH UDHCPC 8 2001-09-26 GNU/Linux "GNU/Linux Administrator's Manual".SH NAMEudhcpc \- very small DHCP client.SH SYNOPSIS.B udhcpc.RI [ OPTION ]....SH DESCRIPTIONThe udhcp client negotiates a lease with the DHCP server andexecutes a script when it is obtained or lost..SH OPTIONS.TP.BI \-c\  CLIENTID ,\ \-\-clientid= CLIENTIDSend the client identifier.IR CLIENTID ..TP.BR -f ,\  \-\-foregroundDo not fork after obtaining a lease..TP.BI \-H\  HOSTNAME ,\ \-\-hostname= HOSTNAMESend the client hostname.IR HOSTNAME ..TP.BI \-h\  HOSTNAMEAlias for -H.IR HOSTNAME ..TP.BI \-i\  INTERFACE ,\ \-\-interface= INTERFACEConfigure.IR INTERFACE ..TP.BR -n ,\  \-\-nowExit with failure if a lease cannot be obtained..TP.BI \-p\  FILE ,\ \-\-pidfile= FILEWrite the process ID of the daemon to.IR FILE ..TP.BR -q ,\  \-\-quitExit after obtaining a lease..TP.BI \-r\  ADDRESS ,\ \-\-request= ADDRESSRequest IP address.IR ADDRESS ..TP.BI \-s\  FILE ,\ \-\-script= FILEUse script.IR FILE ..TP.BR -v ,\  \-\-versionDisplay version..SH USAGEWhen an event occurs,.B udhcpcexecutes a script.  There are four possible arguments to thisscript:.TP.B deconfig.B deconfigis used when.B udhcpcstarts, and when a lease is lost.  The script should put theinterface in an up, but deconfigured, state..TP.B bound.B boundis used when.B udhcpcmoves from an unbound to a bound state.  The script shouldconfigure the interface and set any other relevant parameters(e.g., default gateway, dns server, etc.)..TP.B renew.B renewis used when.B udhcpcwhen a lease is renewed.  The interface is alreadyconfigured, so the IP address will not change.  Other parameters(e.g., default gateway, subnet mask, dns server) may..TP.B nak.B nakis used when.B udhcpcreceieves a NAK packet from the server. Theenviromental variable.B $messagewill contain the reason for theNAK message if the server included one. Processing this messageis optional, as the script will also be called with deconfig ifneed be..PPParameters are passed to the script via the following environmentvariables:.TP.B HOMEThe inherited HOME, or "/" if it is unset..TP.B PATHThe inherited PATH, or "/bin:/usr/bin:/sbin:/usr/sbin" if it isunset..TP.B interfaceThe interface..TP.B ipThe client IP address..TP.B siaddrThe BOOTP next server option..TP.B snameThe BOOTP server name option..TP.B boot_fileThe BOOTP boot file option..TP.B subnetThe subnet mask..TP.B timezoneThe timezone offset from UTC in seconds..TP.B routerThe list of routers..TP.B timesvrThe list of time servers..TP.B namesvrThe list of IEN 116 name servers..TP.B dnsThe list of DNS servers..TP.B logsvrThe list of MIT-LCS UDP log servers..TP.B cookiesvrThe list of RFC 865 cookie servers..TP.B lprsvrThe list of LPR servers..TP.B hostnameThe host name..TP.B bootsizeThe length in 512-octet blocks of the bootfile..TP.B domainThe domain name of the network..TP.B swapsvrThe client's swap server..TP.B rootpathThe path of the client's root dist..TP.B ipttlThe TTL..TP.B mtuThe MTU..TP.B broadcastThe broadcast address..TP.B ntpsrvThe list of NTP servers..TP.B winsThe list of WINS servers..TP.B leaseThe lease time in seconds..TP.B dhcptypeThe DHCP message type (safely ignored)..TP.B serveridThe server IP address..TP.B messageReason for a DHCPNAK..TP.B tftpThe TFTP server name..TP.B bootfileThe bootfile name..SH FILES.TP.I /usr/share/udhcpc/default.scriptScript run when leases are obtained or lost..SH NOTES.B udhcpcresponds to the following signals:.TP.B SIGUSR1This signal causes.B udhcpcto renew the current lease or, if it does not have one, obtain anew lease..TP.B SIGUSR2This signal caused.B udhcpcto release the current lease.