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Error reference · MikroTik

MikroTik: dhcp-client on ether1 lost IP address 203.0.113.25 - received NAK from dhcp server 203.0.113.1

dhcp-client on ether1 lost IP address 203.0.113.25 - received NAK from dhcp server 203.0.113.1

What it means

The ISP’s DHCP server refused to renew the address, so the router lost internet until it gets a new lease.

Why it happens

  • ISP-side change or maintenance.
  • The router changed or the MAC is not the registered one.
  • Two devices with the same MAC on the line.

How to fix it

  1. Release/renew: /ip dhcp-client release [find]; then check it gets a new address.
  2. If the ISP binds by MAC, restore the registered MAC on ether1.
  3. If repeating, ask the ISP for their DHCP logs.

Useful tools

What is my IP

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