Medias Mediatrix 1204, Справочное руководство

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Chapter 8 - IP Address and Network Configuration DHCP Configuration
128 Mediatrix 1204
DHCP Configuration
The following sections describes paramaters that you can set on the Mediatrix 1204 to better interact with a
DHCP server.
DHCP Options Waiting Time
Many network switches use the Spanning Tree Protocol (STP) to manage Ethernet ports activity. If the
Mediatrix 1204 is connected to such a switch, the switch may shut down the matching Ethernet port for at least
one minute. This shutdown on the switch side can prevent proper communication. It may thus take up to three
minutes before the unit receives an answer to its request for DHCP options.
You can configure the Mediatrix 1204 to bypass this waiting period by restarting without a valid address for
the requested servers.
X
To configure how much time the Mediatrix 1204 waits for DHCP options:
1. In the sysConfigMIB , set the amount of time (in seconds) the Mediatrix 1204 will wait for DHCP
options in the sysConfigDhcpWaitDelay variable.
This variable is only effective when the variable sysConfigDhcpWait is set to disable . The default
value is 10 seconds.
2. Define the restart behaviour of a unit that needs to issue a DHCP request to receive some options
in the
sysConfigDhcpWait variable.
This variable has no influence on the wait behaviour in effect when the unit is requesting an IP
address lease from the DHCP server.
Bootp BROADCAST Flag in DHCP Requests
You can define whether the Mediatrix 1204 sets the Bootp BROADCAST flag in DHCP requests it issues.
This applies to the DHCP Discover requests the unit sends on startup. It does not apply to the DHCP Discover
requests sent when renewing the lease.
X
To define the BROADCAST flag behaviour:
1. In the sysConfigMIB , define the BROADCAST flag behaviour in the sysConfigBootpFlags variable.
Table 76: DHCP Wait Parameters
Parameter Description
enable The unit waits up to 130 seconds for DHCP options and then, in the absence of
a response, proceeds to restart without a valid address for the requested
servers. This is the default value.
disable The unit restarts, without valid server addresses, if a DHCP response has not
been received after the amount of time specified in the variable
sysConfigDhcpWaitDelay .
Standards Supported • RFC 1542 – Clarifications and Extensions for the Bootstrap
Protocol
Table 77: BROADCAST Flag Parameters
Parameter Description
noFlags The Bootp BROADCAST flag is not set in DHCP requests that the Mediatrix
1204 issues. The DHCP server may thus answer by using unicast delivery.
broadcastFlag The Bootp BROADCAST flag is set in DHCP requests that the Mediatrix 1204
issues.