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DHCP Scope Showing - Android, Iphone addresses RRS feed

  • Question

  • hello all, 

    I am facing a strange problem 

    I have a dhcp scope on premises - 192.168.40.XX 
    Start 192.168.40.20
    End 192.168.40.200 

    Lease period  = 8 days

    This scope is only for wired clients on our network 

    lately we have seen that our scope is getting full & some clients are not able to receive IP 

    Upon checking the scope i found that there are many addresses showing 192.168.40.30, 40.50, 40.XX which are identified as android, iphone devices on our scope. 

    we physically traced one IP which showed mike_iphone 
    - IP allocated to him on dhcp = 192.168.40.22 
    - Network guy traced his MAC = but it was  not traceable on any port 
    - We personally met mike & checked his Iphone - His Iphone had the same MAC which was being showin on DHCP Scope 
    - To our surprise - He never has connected his iphone through Wire (not possible) so he can never get 192.168.40.XX series IP 
    - Only the user connects his Iphone with a laptop using usb cable for charging purpose

    We are pretty confused as to how his Iphone MAC has entered our DHCP Scope when he has never connected his iphone to our LAN. 

    requesting some Inputs from the forum 

    tfernandes

    Sunday, February 21, 2016 5:31 PM

Answers

  • Found the culprit - It was a We Present device that broadcasts an open SSID so any client can connect & get IP from our DHCP Server.

    Already informed network team to put this device in another VLAN.

    THANKS GUYS FOR THE HELP


    tfernandes

    • Marked as answer by pumping_iron Friday, February 26, 2016 10:04 AM
    Friday, February 26, 2016 10:04 AM

All replies

  • It might be that one of your WiFi access points is connected to the wrong VLAN which makes the phone appear to be connected through cable.

    This posting is provided AS IS with no warranties or guarantees , and confers no rights.

    Ahmed MALEK

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    Sunday, February 21, 2016 5:46 PM
  • Hi pumping_iron,

              >> We are pretty confused as to how his Iphone MAC has entered our DHCP Scope when he has never connected his iphone to our LAN. 

             When wireless access points or wireless routers disable DHCP on them, they will work as switches, then smartphones can connect your network

    with them,and  obtain IP addresses from your wired DHCP server.

     

      Best Regards,

    Cartman


    Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Support, contact tnmff@microsoft.com.

    • Proposed as answer by Hbestregards Thursday, March 3, 2016 5:46 AM
    Monday, February 22, 2016 6:52 AM
  • Found the culprit - It was a We Present device that broadcasts an open SSID so any client can connect & get IP from our DHCP Server.

    Already informed network team to put this device in another VLAN.

    THANKS GUYS FOR THE HELP


    tfernandes

    • Marked as answer by pumping_iron Friday, February 26, 2016 10:04 AM
    Friday, February 26, 2016 10:04 AM
  • Dear pumping_iron
    Good Day !!! 

    please check your wifi settings. its working in access point its connected in VLAN (Desktop or Laptop) DHCP network. 

    if you possible to identifies network check mobile gateway ip address. 

    Thank You 
    Dhananjay 


    Friday, February 26, 2016 10:12 AM