An example of proper DHCP administration is:
Option 242 for DHCP:
MCIPADD =
xxxx.xxx.xxx.xxx
Result
In the following table, the IP deskphones sets the following parameter values to the DHCPACK
message field and option.
Table 6: DHCPACK Setting of Parameter Values
Parameter
Set to
DOMAIN
If received, Option #15.
DHCP lease renew time
Option #58 (if received).
DHCP lease rebind time
Option #59 (if received).
DHCP lease time
Option #51 (if received).
DNSSRVR
Option #6.
HTTPSRVR
The siaddr field, if that field is not a zero.
TLSSRVR
The siaddr field, if that field is non zero.
Because the DHCP site-specific option is processed after the DHCP fields and standard options,
the values set in the site-specific option supersede any values set by DHCP fields or standard
options, as well as any other previously set values.
You cannot set parameters L2Q, L2QVLAN, and PHY2VLAN from a
site-specific option
if the
parameter values were previously set by LLDP.
Note:
The phone do not support Regular Expression Matching, and therefore, do not use wildcards.
In configurations where the upgrade script and the application files are in the default directory
on the HTTP server, do not use the command HTTPDIR=<path>.
Related links
on page 82
Configuring DHCP Option 242
About this task
To administer DHCP option 242 for SSON, make a copy of the existing option 176 for your IP
deskphones. Option 242 is specific to the default site and applies to DHCPv4 only. You can then
perform one of the following actions:
Procedure
1. Ignore any parameters which the IP Deskphones do not support for setting through DHCP
in option 242, or
2. Delete unused or unsupported IP Deskphone parameters to shorten the length of the
DHCP message.
Server Administration
May 2018
Installing and Administering Avaya J169/J179 IP Phone H.323
87