USB LTE Bridge Mode: Laptop gets IP but MikroTik RB750Gr3 doesn't

RouterOS
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Help Request: Connecting USB LTE Modem with Static IP in Bridge Mode to MikroTik hEX RB750Gr3

Hardware Specifications:

  • Router: MikroTik hEX RB750Gr3 (RouterOS v7.20.5)
  • Modem: D-Link DWR-910M (USB LTE Modem)
  • Service: Static IP from local ISP (requires external access)
  • Connection: Via router's USB port

Main Issue:

The DWR-910M modem connects to MikroTik in Bridge mode (NAT disabled) but:

  1. :white_check_mark: Device Detection: MikroTik recognizes the modem as usb1 in /interface print
  2. :white_check_mark: Laptop Connection: When connected directly to a laptop, the laptop obtains an IP without APN configuration
  3. :cross_mark: MikroTik Connection: DHCP Client on MikroTik fails to obtain an IP
  4. :cross_mark: Manual IP: Even with manual IP settings (matching laptop settings), no connection is established

Strange Behavior:

  • Modem in Router mode (NAT enabled) easily provides IP to MikroTik
  • In Bridge mode, it only provides IP to a laptop (Windows)
  • After enabling Bridge mode on the modem, access to its admin panel is lost (until hard reset)

Steps Taken:

  1. Configured DHCP Client on usb1:

    /ip dhcp-client add interface=usb1 disabled=no

  2. Tested manual IP with laptop settings

  3. Temporarily disabled MikroTik firewall

  4. Changed MikroTik MAC address to match laptop's MAC

  5. Factory reset modem and reconfigured

Specific Requirements:

  • Bridge Mode Required: Static IP from ISP must reach MikroTik directly
  • External Access: Internal services must be accessible via Static IP
  • Limited Modem: DWR-910M lacks features like DMZ, Port Forwarding, or UPnP

Questions:

  1. Are there any known issues with RouterOS v7 and this specific modem in Bridge mode?
  2. How can I debug why the laptop gets an IP but MikroTik doesn't?
  3. Do I need specific USB or LTE configuration settings?
  4. Are there alternatives to Bridge Mode given these limitations?

Additional Information:

  • MikroTik does not recognize the modem as LTE, only as usb1 (standard USB network adapter)
  • In Bridge mode, the modem retains APN settings (since laptop connects without APN configuration)

Please advise if you have a solution or need more information.

*For better assistance, please provide specific codes or required commands.

(AI-generated text)*

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Check this page:

If you want your specific device to be included, the only option is to make supout.rif when the device is connected and file a support ticket requesting it will be added.