client.pcy - BOOTP and DHCP client policy
The client.pcy file is a text database, read by the joinc
daemon on startup, which governs the behavior of BOOTP and
DHCP clients. If the JOINCONFIG variable is present in
the joinc environment, it is taken to be the directory
where client.pcy is housed; otherwise joinc searches the
/etc/join directory. Defaults exist for all parameters and
switches, so it is not an error if the file does not
exist.
FORMAT [Toc] [Back]
Blank lines are ignored. The number sign (#) introduces a
comment which continues to the next newline. Each new policy
option must begin and end on a separate line. Policy
options are introduced by a keyword, and may be Boolean,
or may take a value separated from the keyword by whitespace
(but not a newline). If an option is present more
than once, only the value attached to the last occurrence
takes effect - earlier value(s) are forgotten.
KEYWORDS AND VALUES [Toc] [Back]
If no DHCP responses are heard and this flag is set, the
client uses any BOOTP response in the configuration. In
this scenario, the client does not renew, rebind, expire,
or release its IP address lease. In other words the
client is given what is effectively an infinite lease.
Although the client accepts BOOTP responses, it only sends
DHCP packets. There is no guarantee that BOOTP servers
which hear these packets will respond, since they may
become confused by the presence of DHCP data within the
packet. When the client receives an IP address from the
server, it performs an ARP on the local network to verify
that no other client is using the address. If the client
receives no reply after seconds expires, it assumes that
it may use the address.
Default: 2 seconds. The client's class ID. Consult
RFC1541 for details. Use a client identifier other than
the MAC address. Currently setting client_id tells the
DHCP client daemon to use a concatenation of the MAC
address and the interface name as the client ID. The MAC
address is in internal form, not the readable, colon-separated
string. You must use this option when configuring a
client with multiple interfaces and where the client's MAC
address is the same on each interface (SUN hardware for
example). The DHCP server grants the client permission to
use an IP address for a fixed period of time (which may be
infinite). In the language of DHCP, the client is granted
a "lease" on the IP address. With this parameter, the
client may request a lease of a particular duration,
although servers are not bound to honor the request. If
the client does not care, seconds should be set to zero;
if an infinite lease is required, to minus one, -1. Otherwise
specify in seconds the lease duration required.
Default: 0 This parameter is subtly different from the
number of retries a client will make as part of an exponential
broadcast retry backoff. Rather it is the number
of separate attempts the client will make to contact a
server, assuming that replies are received, but that the
client, for one reason or another, rejected those replies.
Default: 2 Clients are required by the DHCP protocol to
implement an exponential retransmission and backoff when
broadcasting discover or request packets. The array of
values specifies how long the client should wait for
replies before timing out and retrying the broadcast.
Each time the client sends a DHCP protocol packet,
it waits for a response until a timeout occurs as
specified by a member of this array (in seconds).
If a timeout has occurred, the packet is retransmitted
with the same XID (see RFC 1541) and the
timeout is set to the next positive number in the
comma-separated list. The last element in the list
is negative or zero. After all specified timeouts
have been tried, the next action depends on options
to the dhcpconf program. One option is to fail;
another is to retry forever. See dhcpconf(8) for
further information. If the last value is negative,
DHCP suspends configuration of the interface
for an amount of time given by the negative number
terminating the array. During this time, the
interface is considered idle; the client is not
expecting responses destined for the interface and
will ignore any that arrive. When the idle time is
over, the client begins retransmitting with a timeout
given by the first element in the array and a
new XID. If the last value is zero, the client
continues to use the same XID and timeout of the
last positive value in the array.
Default: 4,8,16,32,0 If there is no reply to DHCP,
and use_saved_config is set, then use the configuration
stored in <interface>.cf from a previous
invocation of the protocol providing the lease is
still valid. The DHCP protocol requires clients to
delay a random time interval on booting, and after
each timeout, before broadcasting to the net. This
is to prevent network "flooding" in the event that
many clients try to configure simultaneously (say
after a sitewide power-up). This parameter is the
maximum delay that the client will tolerate. The
actual delay is randomized from zero to seconds.
Note that on each timeout the client will also
delay, and that the second and subsequent delays
are also random, and need not be the same as the
first.
Default: 10 seconds. There may be many instances
of the request keyword, each with a different
parameter_name. Each parameter that is configurable
through DHCP and the server extensions is
identified by a unique parameter. Limited size of
DHCP packets dictates that a client should not
request data which it cannot use. However, different
DHCP servers, or different server policies may
dictate that a server return more configuration
than a client requested. For a description of the
meaning of the various parameters, consult RFC1542
and others to which it refers. Valid options follow.
The first group are DHCP generic:
all_subnets_are_local
arp_cache_timeout
boot_file
boot_file_server
boot_size
broadcast_address
cookie_server
default_ip_timeto-
live
dns_domain_name
dns_servers
ether-
net_encapsu-
lation
extensions_path
home_directory
host_name
impress_server
interface_mtu
ip_forward-
ing
keepalive_garbage
lease_time
log_server
lpr_server
mask_supplier
maxi-
mum_datagram_reassem-
bly_size
merit_dump_file
name_server
netbios_data-
gram_distri-
bution_server
netbios_name_server
netbios_node_type
netbios_scope
nis_domain_name
nis_server
nonlocal_source_rout-
ing
ntp_server
path_mtu_aging_timeout
path_mtu_plateau_table
perform_mask_dis-
covery
perform_router_dis-
covery
policy_filter
rebinding_time_value
renewal_time_value
resource_location_server
root_path
router
router_solici-
tation_address
static_routes
subnet_mask
swap_server
tcp_default_time_to_live
tcp_keepalive_interval
time_offset
time_server_(rfc_868)
trailer_encapsu-
lation
x_window_dis-
play_manager
x_windows_font_server
The following are specific to the DHCP server:
nfs_mounted_file_systems
svr4_printer_setup
printers
joinc(8)
DARPA Internet Request For Comments RFC 1541, RFC 1542
delim off
client.pcy(4)
[ Back ] |
