I'm working to configure a Juniper Networks switch through Zero Touch Provisioning. On CentOS 7, the journal/log/(systemd whatever-it-is) contains this:

Nov 28 10:08:46 server dhcpd[8800]: Checking if packet is permitted.
Nov 28 10:08:46 server dhcpd[8800]:     Permit list: unknown clients
Nov 28 10:08:46 server dhcpd[8800]:    OK
Nov 28 10:08:46 server dhcpd[8800]: Checking if packet is permitted.
Nov 28 10:08:46 server dhcpd[8800]:     Permit list: unknown clients
Nov 28 10:08:46 server dhcpd[8800]:    OK
Nov 28 10:08:46 server dhcpd[8800]: matched a Juniper Networks QFX-5100
Nov 28 10:08:46 server dhcpd[8800]: DHCPDISCOVER from 08:b2:58:ab:dc:00 via eth2
Nov 28 10:08:47 server dhcpd[8800]: DHCPOFFER on 192.168.0.100 to 08:b2:58:ab:dc:00 (TR0217010017) via eth2
Nov 28 10:08:47 server dhcpd[8800]: Checking if packet is permitted.
Nov 28 10:08:47 server dhcpd[8800]:     Permit list: unknown clients
Nov 28 10:08:47 server dhcpd[8800]:    OK
Nov 28 10:08:47 server dhcpd[8800]: Checking if packet is permitted.
Nov 28 10:08:47 server dhcpd[8800]:     Permit list: unknown clients
Nov 28 10:08:47 server dhcpd[8800]:    OK
Nov 28 10:08:47 server dhcpd[8800]: matched a Juniper Networks QFX-5100
Nov 28 10:08:47 server dhcpd[8800]: DHCPREQUEST for 192.168.0.100 (192.168.0.250) from 08:b2:58:ab:dc:00 (TR0217010017) via eth2
Nov 28 10:08:47 server dhcpd[8800]: DHCPACK on 192.168.0.100 to 08:b2:58:ab:dc:00 (TR0217010017) via eth2

The server is vending from the "unknown" pool. Here are the relevant portions of the config:

# Global options
max-lease-time 1800;
default-lease-time 1800;
dynamic-bootp-lease-length 120;
ddns-update-style none;

# TFTP Server IP and file
next-server 192.168.0.250; # Assumed to be the DHCP server
filename "pxelinux.0";


# Define the pxe grub filename option
option zone-pxegrub-filename code 150 = text;
option zone-pxegrub-filename "/opt/tftp_files/boot/pxelinux.0";

# Options for Juniper switch to download FW and configuration from this server
# as described here: https://www.juniper.net/documentation/en_US/junos/topics/task/configuration/software-image-and-configuration-automatic-provisioning-confguring.html
option space NEW_OP;
option NEW_OP.config-file-name code 1 = text;
option NEW_OP.image-file-name code 0 = text;
option NEW_OP.image-file-type code 2 = text;
option NEW_OP.transfer-mode code 3 = text;
option NEW_OP.alt-image-file-name code 4 = text;
option NEW_OP-encapsulation code 43 = encapsulate NEW_OP;
option option-150 code 150 = ip-address;

# bringing in the vendor specific options
vendor-option-space NEW_OP;
option NEW_OP.image-file-name "/juniper/fw/jinstall-host-qfx-5-17.2R1.13-signed.tgz";
option NEW_OP.config-file-name "/juniper/cfg/qfx-5100.cfg";
option NEW_OP.alt-image-file-name "/juniper/fw/jinstall-host-qfx-5-17.2R1.13-signed.tgz";
option NEW_OP.image-file-type "filename";
option NEW_OP.transfer-mode "tftp";

option option-150 192.168.0.250;


class "workers" {
   match if substring(hardware, 1, 3) = 00:20:0c or substring(hardware, 1, 3) = 00:18:7D;
   log(info, "matched a worker bee");
}

class "monitor" {
   match if substring(hardware, 1, 3) = 00:d0:24;
   log(info, "matched to a monitor");
}

class "JuniperSwitch" {
   match if option vendor-class-identifier ~~ "^juniper-qfx5100.+$";
   log(info, "matched a Juniper Networks QFX-5100");
}

subnet 192.168.0.0 netmask 255.255.255.0 {
   #authoritative;
   option routers 192.168.0.250;
   pool {
      allow members of "workers";
      range 192.168.0.1 192.168.0.99;
      log(info, concat("Issuing DHCP address to worker bootp requestor: ", binary-to-ascii(16, 8, ":", substring(hardware, 1, 6))));
   }
   pool {
      allow members of "monitor";
      range 192.168.0.245;
      log(info, concat("Issuing DHCP address to monitor bootp requestor: ", binary-to-ascii(16, 8, ":", substring(hardware, 1, 6))));
   }
   pool {
      allow members of "JuniperSwitch";
      allow dynamic bootp clients;
      range 192.168.0.201;
   }
   pool {
      allow unknown-clients;
      range 192.168.0.100 192.168.0.150;
   }
}

Please, help me to understand why this isn't vending an address where I expect.