Hirschmann GREYHOUND GRS1020, Справочное руководство

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Specifying the IP parameters
2.6 Specifying the IP parameters using DHCP
52
UM Config GRS
Release 8.0 09/2019
2.6 Specifying the IP parameters using DHCP
The DHCP (Dynamic Host Configuration Protocol) is a further development of BOOTP, which it has
replaced. The DHCP additionally lets the configuration of a DHCP client using a name instead of
using the MAC address.
For the DHCP, this name is known as the “Client Identifier” in accordance with RFC 2131.
The device uses the name entered under sysName in the system group of the MIB II as the Client
Identifier. You can change the system name using the graphic user interface (see dialog Basic
Settings > System ), the Command Line Interface or SNMP.
The device sends its system name to the DHCP server. The DHCP server then uses the system
name to allocate an IP address as an alternative to the MAC address.
In addition to the IP address, the DHCP server sends

the netmask

the default Gateway (if available)

the TFTP URL of the configuration file (if available).
The device applies the configuration data to the appropriate parameters. When the DHCP Sever
assigns the IP address, the device permanently saves the configuration data in non-volatile
memory.
The advantage of using DHCP instead of BOOTP is that the DHCP server can restrict the validity
of the configuration parameters (“Lease”) to a specific time period (known as dynamic address
allocation). Before this period (“Lease Duration”) elapses, the DHCP client can attempt to renew
this lease. Alternatively, the client can negotiate a new lease. The DHCP server then allocates a
random free address.
To help avoid this, DHCP servers provide the explicit configuration option of assigning a specific
client the same IP address based on a unique hardware ID (known as static address allocation).
In the default setting, DHCP is activated. As long as DHCP is activated, the device attempts to
obtain an IP address. When the device cannot find a DHCP server after restarting, it will not have
an IP address. The
Basic Settings > Network
dialog lets you activate or deactivate DHCP.
Note: When using Industrial HiVision network management, verify that DHCP allocates the original
IP address to every device.
Table 10: DHCP options which the device requests
Options Meaning
1 Subnet Mask
2 Time Offset
3 Router
4 Time server
12 Host Name
42 NTP server
61 Client Identifier
66 TFTP Server Name
67 Bootfile Name