This KB explains a PoE issue on a Juniper EX2300 switch where an Extreme Networks AP410c consistently runs in low power mode, even though PoE is fully enabled with a 30W power limit and high priority.

The same switch and configuration successfully power an Extreme AP3935 in normal mode. Both APs are connected to access ports with identical configurations, and the switch reports 30W maximum power allocated to each port.

Troubleshooting steps performed so far:

• Verified PoE is enabled and set to high priority on all AP ports.
• Power limit manually set to 30W on affected ports.
• Verified switch PoE budget is not exceeded.
• AP410c firmware is current and functioning otherwise.

Despite this, the AP410c always boots into low power mode. The AP3935 on the same switch operates normally.

We suspect a PoE negotiation or voltage delivery issue between the EX2300 and AP410c

• Configuration as follows:

set protocols lldp interface all power-negotiation

set protocols lldp-med interface all

set protocols lldp-med tlv-select ext-power-via-mdi

set protocols lldp-med tlv-select location-id

set protocols lldp-med tlv-select med-capabilities

set protocols lldp-med tlv-select network-policy

set poe management class

set poe lldp-priority

set poe interface all maximum-power 30

set poe interface all telemetries

set poe interface ge-0/0/46 disable

set poe interface ge-0/0/47 disable

set poe interface wireless priority high

set poe interface wireless maximum-power 30

set poe interface wireless telemetries

set poe interface ge-0/0/0

root@EX2300> show poe interface ge-0/0/0 
Dec 07 16:12:51
PoE interface status:
PoE interface                :  ge-0/0/0
Administrative status        : Enabled
Operational status           :   ON
Operational status detail    : IEEE PD Detected
FourPair status              : Disabled
Power limit on the interface : 30.0W
Priority                     : High
Power consumed               : 7.2W
Class of power device        :        4
PoE Mode                     :   802.3at

• According to the PCAP and outputs, the LLDP is not being negotiated, but the switch is providing enough power.
• The switch is providing 7.2 W ~ 7.4 W
• The PoE class is 4 for 802.3at, with a Power Range of Powered Device is 12.95 through 25.5 W
  • Table 2: Class of Powered Device and Power Levels
• IEEE 802.3at (PoE+): Supplies up to 30 W of power. The PoE+ standard provides support for legacy PoE devices—an IEEE 802.3af powered device can operate normally when connected to IEEE 802.3at (PoE+) power sourcing equipment.
  • Understanding PoE on EX Series Switches | Junos OS | Juniper Networks
• Also, the output does not display the (L) in the show poe interface.
• An (L) next to the value indicates that the value on the port was negotiated by LLDP. show poe interface | Junos OS | Juniper Networks

• Issue resolved and APs are able to negotiate after deleting the config for interface-range wireless interfaces (ge-0/0/0 to ge-0/0/11) from LLDP-MED.

{master:0}[edit]
root@EX2300# delete protocols lldp-med interface all     

{master:0}[edit]
root@EX2300# show | compare 
[edit protocols lldp-med]
-    interface all;

{master:0}
root@EX2300> show poe interface ge-0/0/0 
Dec 07 16:12:51
PoE interface status:
PoE interface                :  ge-0/0/0
Administrative status        : Enabled
Operational status           :   ON
Operational status detail    : IEEE PD Detected
FourPair status              : Disabled
Power limit on the interface : 25.5W (L)
Priority                     : High
Power consumed               : 8.0W
Class of power device        :        4
PoE Mode                     :   802.3at
  (L) LLDP-negotiated value on the port.

{master:0}
root@EX2300> show poe interface 
Dec 07 16:12:45
Interface    Admin       Oper    Pair/Mode  Max        Priority       Power          Class
             status      status  status     power                     consumption    
 ge-0/0/0    Enabled      ON     2P/AT      25.5W(L)   High           7.8W            4
 ge-0/0/1    Enabled      ON     2P/AT      19.4W(L)   High           8.2W            4

• Some APs may not expect or properly handle LLDP-MED TLVs, which can interfere with their negotiation or operation.
• LLDP-MED is enabled by default on all interfaces, and you can selectively enable or disable it per interface or interface range. Disabling LLDP-MED on interfaces connected to devices that do not support or expect it (such as certain APs) is a recommended practice to avoid compatibility issues.
• Disabling TLVs
  • In multi-vendor networks, it might not be desirable to send TLV messages because they can contain sensitive information about a network device. You can configure LLDP or LLDP-MED to disable any non-mandatory TLV message. Mandatory TLVs are: chassis-id, port-id, and time-to-live. All other TLVs can be disabled, either on specific interfaces or on a global basis
    • Device Discovery Using LLDP | Junos OS
    • Configuring Junos OS on the EX2300