Description

Note: A product listed in this article has either reached hardware End of Life (EOL) OR software End of Engineering (EOE).  Refer to End of Life Products & Milestones for the EOL, EOE, and End of Support (EOS) dates.

The EX series Switch, acting as local DHCP server, fails to forward the "Next Server" IP Address resulting in the Alcatel Lucent IP Touch 4028 Phone failing to download the configuration file from the TFTP server EX series Switch using Options 66 and 67

Symptoms

Alcatel Lucent IP Touch 4028 phone fails to download the configuration file from the Alcatel Core PBX / TFTP server with EX series Switch serving as the local DHCP server with the following configuration:

dhcp {
   pool 192.178.1.0/24 {
      address-range low 192.178.1.71 high 192.178.1.75;
      boot-file lanpbx.cfg; <-- Option 67
      boot-server 192.178.1.1; <-- Option 66


Wireshark captures of DHCP exchange between Local DHCP server (EX Switch) and the IP Touch Phone indicate that the Next Server IP address is not being forwarded by the EX Switch.

Capture:
A look at the DHCP offer packet under Bootstrap Protocol shows 0.0.0.0 (0.0.0.0) Next Server IP Address. 

Topology:

IP Touch Phone ------- EX4200 (DHCP Server) --------Juniper 550 Firewall -----------Core switch ------- TFTP Server

Solution

NOTE: This article assumes that all routing is working as expected.

In order for the IP Touch Phone to download the configuration file successfully from the TFTP server you must define the next-server ip address on the EX Switch.   The next-server ip address must be the same as the TFTP server IP address.  If DHCP is working properly, then after adding Next-Server paramter to the configuration the IP Touch Phone should now be able to down load it's configuration file from it's TFTP Server.

- Define the next-server IP address on the EX Switch
- next-server IP address must be the same as the TFTP server IP address

Topology:

IP Touch Phone ------- EX4200 (DHCP Server) --------Juniper 550 Firewall -----------Core switch ------- TFTP Server

Configuration:

{master:0}[edit system services dhcp]
juniper@juniper# show

pool 192.178.1.0/24 {
address-range low 192.178.1.71 high 192.178.1.75;
router {
192.178.1.10;
}
boot-file lanpbx.cfg;
boot-server 192.178.1.1;
next-server 192.178.1.1;
}

 

Modification History

2020-10-28: Tagged article for EOL/EOS.