49 lines
1.5 KiB
Groff
49 lines
1.5 KiB
Groff
.TH DHCP 1
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.SH NAME
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dhcp - obtain network configuration via DHCP
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.SH SYNOPSIS
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dhcp
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.SH DESCRIPTION
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The DHCP client automatically obtains an IP address, subnet mask,
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default gateway, and other network parameters from a DHCP server
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on the local network using the Dynamic Host Configuration Protocol
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(RFC 2131).
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On success the network configuration is applied immediately via
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set_netcfg(). On failure the original configuration is restored.
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The client is run automatically by the init system at boot, but
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may also be invoked manually from the shell.
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.SH PROTOCOL
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The client performs the standard four-message DHCP exchange:
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1. DHCPDISCOVER Broadcast to 255.255.255.255:67
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2. DHCPOFFER Server offers an IP address
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3. DHCPREQUEST Client accepts the offered address
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4. DHCPACK Server confirms the lease
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The BROADCAST flag (0x8000) is set so that server replies are
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sent to the broadcast address, since the client has no IP yet.
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Each step has a 10-second timeout. If no response is received
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the client exits with an error and restores the previous config.
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.SH OUTPUT
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On success the client prints the assigned configuration:
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IP Address, Subnet Mask, Gateway, DNS Server, Lease Time
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.SH OPTIONS
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The DHCP client requests the following options from the server:
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1 Subnet Mask
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3 Router (default gateway)
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6 DNS Server
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51 Lease Time
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.SH SEE ALSO
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ifconfig(1), shell(1), syscalls(2)
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