Tahoe 684, User Manual

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masks, gateway and DNS addresses and other parameters to the
network stations. It is easy to reconfigure a network that uses a DHCP
server - it is enough to change server settings and every station will
automatically retrieve new configuration.
The BOOTP protocol is an earlier and simpler version of DHCP. Its
common use is booting of diskless workstations. A workstation uses
BOOTP to get its IP address and other network parameters together with
TFTP server address, from which the operating system may be
downloaded.
The DHCP protocol may deliver more working parameters
including domain name, DNS address, print server, syslog server, X-
Window fontserver, MTU and TTL settings, and many others.
DHCP/BOOTP Relay Agent transfers DHCP and BOOTP requests
and replies between separate networks. The DHCP and BOOTP protocols
work only within one physical subnet. The station using such protocols
doesn’t know its IP address yet, so its packets cannot be routed to other
networks. Relay Agent listens for such requests and forwards them to a
DHCP server, which may be placed anywhere in the network.
4.3.7.1. Review of the settings
Entering “dhcp” alone displays current server settings. Here is an
example:
Tahoe> dhcp
DHCP/BOOTP server
default-lease-time 43200
max-lease-time 86400
network "lan" (eth0):
default-lease-time 43200
max-lease-time 86400
domain-name tahoe.pl
subnet "local": 10.0.0.0/255.255.255.0
default-lease-time 43200
max-lease-time 86400
filename vmlinuz.2.2.19
next-server 192.168.0.5
routers 10.0.0.1
domain-name-servers 192.168.0.4
domain-name tahoe.pl
address ranges: 10.0.0.3-10.0.0.15
relay server 192.168.0.5 67
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4.3.7.2. Basic DHCP server configuration rules
Before starting using DHCP server please read following
guidelines:
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the configuration is organized in a hierarchical manner - the most
general group of settings is “network” - the physical network
connected to the modem. Any number of IP “subnets” may exist
within a network. Inside an IP subnet an IP address “range” may
be selected - these addresses will be dynamically assigned to the
network stations.
A static connection between an IP address and a
hardware address may also be set. Each group (“network”,
“subnet”) has its own options. Creating a new group (e.g. a
“subnet” within a “network”) causes copying of the options from
the parent group (e.g. if the “lan” network has a “domain-name”
option, after adding a “local” subnet within “lan” the option will be
automatically copied - it may be modified or deleted later)
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on the beginning a “network” for each interface should be created
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in each of the “networks” an IP “subnet” should be created
according to IP subnets connected to that interface (modem may
not have the routing set up to each of them - it’s enough that they
are in the same physical network)
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now IP ranges and static IP entries may be added
4.3.7.3. dhcp [ on | off | relay ]
DHCP/BOOTP server may work in one of three modes:
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on - the server in enabled and answers to the requests
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off - the server is disabled
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relay - the server is disabled, but the relay agent is enabled and
listens for the requests to be forwarded to other DHCP server
4.3.7.4. dhcp add
The “dhcp add” commands add a network, subnet, IP range, etc.
Following variants are supported:
¡
dhcp add network <name>
Adds a new physical network connected to the modem’s interface.
There should be the same number of “networks” and interfaces. The
“network”-interface connection will be determined later while adding the
IP subnets.
4.3.7.1
4.3.7.4
4.3.7.3
4.3.7.2