| .TH UDHCPC 8 2001-09-26 GNU/Linux "GNU/Linux Administrator's Manual" |
| .SH NAME |
| udhcpc \- very small DHCP client |
| .SH SYNOPSIS |
| .B udhcpc |
| .RI [ OPTION ]... |
| .SH DESCRIPTION |
| The udhcp client negotiates a lease with the DHCP server and |
| executes a script when it is obtained or lost. |
| .SH OPTIONS |
| .TP |
| .BI \-c\ CLIENTID ,\ \-\-clientid= CLIENTID |
| Send the client identifier |
| .IR CLIENTID . |
| .TP |
| .BR -f ,\ \-\-foreground |
| Do not fork after obtaining a lease. |
| .TP |
| .BI \-H\ HOSTNAME ,\ \-\-hostname= HOSTNAME |
| Send the client hostname |
| .IR HOSTNAME . |
| .TP |
| .BI \-h\ HOSTNAME |
| Alias for -H |
| .IR HOSTNAME . |
| .TP |
| .BI \-i\ INTERFACE ,\ \-\-interface= INTERFACE |
| Configure |
| .IR INTERFACE . |
| .TP |
| .BR -n ,\ \-\-now |
| Exit with failure if a lease cannot be obtained. |
| .TP |
| .BI \-p\ FILE ,\ \-\-pidfile= FILE |
| Write the process ID of the daemon to |
| .IR FILE . |
| .TP |
| .BR -q ,\ \-\-quit |
| Exit after obtaining a lease. |
| .TP |
| .BI \-r\ ADDRESS ,\ \-\-request= ADDRESS |
| Request IP address |
| .IR ADDRESS . |
| .TP |
| .BI \-s\ FILE ,\ \-\-script= FILE |
| Use script |
| .IR FILE . |
| .TP |
| .BR -v ,\ \-\-version |
| Display version. |
| .SH USAGE |
| When an event occurs, |
| .B udhcpc |
| executes a script. There are four possible arguments to this |
| script: |
| .TP |
| .B deconfig |
| .B deconfig |
| is used when |
| .B udhcpc |
| starts, and when a lease is lost. The script should put the |
| interface in an up, but deconfigured, state. |
| .TP |
| .B bound |
| .B bound |
| is used when |
| .B udhcpc |
| moves from an unbound to a bound state. The script should |
| configure the interface and set any other relevant parameters |
| (e.g., default gateway, dns server, etc.). |
| .TP |
| .B renew |
| .B renew |
| is used when |
| .B udhcpc |
| when a lease is renewed. The interface is already |
| configured, so the IP address will not change. Other parameters |
| (e.g., default gateway, subnet mask, dns server) may. |
| .TP |
| .B nak |
| .B nak |
| is used when |
| .B udhcpc |
| receieves a NAK packet from the server. The |
| enviromental variable |
| .B $message |
| will contain the reason for the |
| NAK message if the server included one. Processing this message |
| is optional, as the script will also be called with deconfig if |
| need be. |
| .PP |
| Parameters are passed to the script via the following environment |
| variables: |
| .TP |
| .B HOME |
| The inherited HOME, or "/" if it is unset. |
| .TP |
| .B PATH |
| The inherited PATH, or "/bin:/usr/bin:/sbin:/usr/sbin" if it is |
| unset. |
| .TP |
| .B interface |
| The interface. |
| .TP |
| .B ip |
| The client IP address. |
| .TP |
| .B siaddr |
| The BOOTP next server option. |
| .TP |
| .B sname |
| The BOOTP server name option. |
| .TP |
| .B boot_file |
| The BOOTP boot file option. |
| .TP |
| .B subnet |
| The subnet mask. |
| .TP |
| .B timezone |
| The timezone offset from UTC in seconds. |
| .TP |
| .B router |
| The list of routers. |
| .TP |
| .B timesvr |
| The list of time servers. |
| .TP |
| .B namesvr |
| The list of IEN 116 name servers. |
| .TP |
| .B dns |
| The list of DNS servers. |
| .TP |
| .B logsvr |
| The list of MIT-LCS UDP log servers. |
| .TP |
| .B cookiesvr |
| The list of RFC 865 cookie servers. |
| .TP |
| .B lprsvr |
| The list of LPR servers. |
| .TP |
| .B hostname |
| The host name. |
| .TP |
| .B bootsize |
| The length in 512-octet blocks of the bootfile. |
| .TP |
| .B domain |
| The domain name of the network. |
| .TP |
| .B swapsvr |
| The client's swap server. |
| .TP |
| .B rootpath |
| The path of the client's root dist. |
| .TP |
| .B ipttl |
| The TTL. |
| .TP |
| .B mtu |
| The MTU. |
| .TP |
| .B broadcast |
| The broadcast address. |
| .TP |
| .B ntpsrv |
| The list of NTP servers. |
| .TP |
| .B wins |
| The list of WINS servers. |
| .TP |
| .B lease |
| The lease time in seconds. |
| .TP |
| .B dhcptype |
| The DHCP message type (safely ignored). |
| .TP |
| .B serverid |
| The server IP address. |
| .TP |
| .B message |
| Reason for a DHCPNAK. |
| .TP |
| .B tftp |
| The TFTP server name. |
| .TP |
| .B bootfile |
| The bootfile name. |
| .SH FILES |
| .TP |
| .I /usr/share/udhcpc/default.script |
| Script run when leases are obtained or lost. |
| .SH NOTES |
| .B udhcpc |
| responds to the following signals: |
| .TP |
| .B SIGUSR1 |
| This signal causes |
| .B udhcpc |
| to renew the current lease or, if it does not have one, obtain a |
| new lease. |
| .TP |
| .B SIGUSR2 |
| This signal caused |
| .B udhcpc |
| to release the current lease. |