Switching

I need to do asetup at which my EX switch will be DHCP Server for Avaya phone

i will use the belwo DHCP configuration but i heared that i need to configure something called DHCP options ? Why ? How?

root@EX# set system services dhcp pool 192.168.2.0/24 address-range low 192.168.2.10
root@EX# set system services dhcp pool 192.168.2.0/24 address-range high 192.168.2.100

root@EX# set system services dhcp pool 192.168.2.0/24 domain-name Juniper.net
root@EX# set system services dhcp pool 192.168.2.0/24 name-server 192.168.2.1
root@EX# set system services dhcp pool 192.168.2.0/24 router 192.168.2.1

When the phone first boots up it is technically a dumb device.  It has no configuration or settings applied.  Somehow the phone must be told where its Call Manager is so it may go request its configuration file.  The main way most people achieve this is by putting the location of the Call Manager in what is called an IP option.

When the phones gets an IP from the DHCP server it is also given an extra field with a value ( in your case this would be the IP of the call manager).  These extra fields are called DHCP options.  They are handed out as an Option # and value.

you configure them under the system services dhcp pool hierarchy

ex)

set system services dhcp pool 192.168.0.0/24 option 43 .......

The phone will only listen for the proper option number so you must get this from the manufacturer specs.

Alternatively you can just allow the Call Manager to be the DHCP server and setup a DHCP forwarded in the Voice VLAN.  This is typically the model I choose because it removes a layer that the "Network Team" has to support.  All voice stuff lives on the voice server.

Thanks Alot magraw

for avaya it will be :

set system services dhcp pool 192.168.0.0/24 option 176

This is option 176 , but how will i tell it the Ip of Call Manager from this opton 176 ?

Actually if you just typed what you had there with the ? you would have seen all the options

magraw@ex# set system services dhcp pool 192.168.0.0/24 option 176 ?
Possible completions:
  <[Enter]>            Execute this command
> array                Array of values
  byte                 Unsigned 8-bit value
  byte-stream          Stream of unsigned 8-bit values within quotes
  flag                 Boolean flag value
  integer              Signed 32-bit numeric value
  ip-address           IP address value
  short                Signed 16-bit numeric value
  string               Character string value
  unsigned-integer     Unsigned 32-bit numeric value
  unsigned-short       Unsigned 16-bit numeric value
  |                    Pipe through a command
[edit]

The one you want is ip-address < Enter IP HERE>

full command would be

set system services dhcp pool 192.168.0.0/24 option 176 ip-address x.x.x.x

Thanks Alot

Hello Experts,

I am trying to configure DHCP option 43 and each time i try, i get this error message:

{master:1}[edit system services dhcp]
admin@NET-AS-EX4200_24P-ADM-01# show
router {
10.10.10.1;
}
pool 10.10.10.0/24 {
address-range low 10.10.10.5 high 10.10.10.20;
option 43 string ip:10.10.90.1;
}
pool 10.10.19.0/24 {
address-range low 10.10.19.3 high 10.10.19.50;
}

{master:1}[edit system services dhcp]
admin@NET-AS-EX4200_24P-ADM-01# commit synchronize
[edit system services dhcp pool 10.10.10.0/24 option 43 string]
'string ip:10.10.90.1'
Option 43 must be defined as an array type
error: configuration check-out failed

Please what am i doing wrong???

Thanks!

Regards,

James.

DHCP option 43 is a pain.  It has to be defined in a "special" way.

http://kb.juniper.net/InfoCenter/index?page=content&id=KB19509&actp=RSS

so i'm not clear, are you saying it has to be prefaced with:

set system services dhcp pool 10.0.3.0/24 option 43 byte-stream "108 112 58 .. .. ..

for lower case ip:

In this context, what do options 43 and 176 tell the phone?