GS1900-24HP Disabled Ports continuing to provide power and temporarily routing traffic

danyedinak Posts: 51  Ally Member
First Anniversary 10 Comments Friend Collector
edited August 2022 in Switch
I have a GS1900-24HP running 2.40(AAHM.0)C0 on which I had disabled two specific network ports upon the departure of an employee (and, yes, the config file was saved when the change was made). A couple of weeks later, a new employee started and was able to plug in the previously used PoE VOIP phone, get power, and even use it for several days before finally calling to report that the phone had "stopped" working (no dial tone, but phone still had power).
In addition, the MAC table shows the USG60W, which is connected on Port 1, as being connected on Port 14 as Static Unicast. The switch serves only a single network, so everything is on default(1) VLAN. Several ports are configured in QOS, but nothing extraordinary. The MAC table, however, is also showing devices on other networks that are connecting wirelessly as though they are on Port 1. Those wireless devices connecting through the USG, and on SSIDs that are configured on an entirely separate subnet - one with security policies that should be preventing visibility of the network the switch is on (which I can confirm by trying to access that network).
This device was only installed about a year ago. Up time is currently at 66 days. 
Am I looking at a failing switch? Or can anyone else confirm similar problems?


  • Zyxel_Ryan
    Zyxel_Ryan Posts: 72  Zyxel Employee
    Friend Collector First Answer First Comment
    Hi @danyedinak

    Based on your description, I assume your topology looks like below. If not, please let me know it more clearly.

    Port Enable/ Disable setting and PoE Enable/ Disable setting are actually two different settings. 
    Port Enable/ Disable setting: Configuration > Port > Port > State
    PoE Enable/ Disable setting: Configuration > Port > PoE > PD State
    It is a normal behavior that PoE still provides power if you only disable port.
    If you found IP Phone can forward traffic and is usable, please check port status on Monitor > Port > Port

    About Static Unicast, do you set static MAC (Configuration > MAC Table > Static MAC) on port 14? If yes, I think you should set it on port 1, rather than port 14 because your USG60W is connected on port 1. 

    Regarding you found MAC of AP clients are shown on MAC table of GS1900, how do you set AP? 
    What is your Outgoing Interface of AP and on what port did GS1900 connected with (P3 or P4)?