# OpenWrt

## Contents

## How to override the WAN MAC address

My ISP's fiber optic modem refused to let any device connect unless it had a specific [MAC address](!W). When I got a [TP-Link Archer C7 AC1750](https://openwrt.org/toh/tp-link/archer-c5-c7-wdr7500) router and installed OpenWRT on it, this proved a problem. The MAC address I set through the web interface did not actually override the router's WAN MAC address. I found a [bug](https://dev.archive.openwrt.org/ticket/18488) describing this issue in OpenWRT's tracker. Rather than edit `/etc/config/network` like one of the comments suggested, I wrote an rc script that set the MAC address.

### `/etc/rc.d/99set_mac`

```sh
#! /bin/sh /etc/rc.common

START=99

MAC_ADDRESS=00:23:69:15:5C:81
MAC_IF=eth0.2

start() {
    ifconfig "$MAC_IF" down
    ifconfig "$MAC_IF" hw ether "$MAC_ADDRESS"
    ifconfig "$MAC_IF" up
}
```

### Reference

- ["Override mac address doesn't work on wan"](https://dev.archive.openwrt.org/ticket/18488) 

## Page metadata

URL: <https://dbohdan.com/openwrt.md>

Published 2021-07-16, updated 2022-12-30.

Tags:

- how-to
- sysadmin
- troubleshooting