The SRX has a DHCP pool set up for a network of Access Points on the 192.168.0.0/21 network. Administrator is using AP's which require the use of Option 78 to connect to a controller on a different Layer 2 domain. As such, he's configured the below on the AP DHCP pool to distribute option 78 with the appropriate HEX value of the controller (10.1.72.8). Upon reviewing a packet capture, the DHCP Offer packet does not include any reference to Option 78.

Here is the configuration:

[edit access address-assignment]

root# show

pool WAPs-Pool {

  family inet {

    network 192.168.0.0/21;

    range MGMT {

      low 192.168.0.10;

      high 192.168.7.250;

    }

    dhcp-attributes {

      maximum-lease-time 86400;

      name-server {

        8.8.8.8;

      }

      router {

        192.168.0.1;

      }

      option 78 hex-string 010a014808;

    }

  }

}

After configuring the process-inform knob, option 78 started showing in the pcaps.

Please refer to this document for more information about this knob and its hierarchy:

process-inform

https://www.juniper.net/documentation/us/en/software/junos/cli-reference/topics/ref/statement/process-inform-edit-system-services-overrides.html