+###### "Address X/Y cannot be used on interface Z."
+
+`nmrpflash` refuses to use an IP address / subnet mask combination that would
+make the remote device unreachable from the device running `nmrpflash`. For
+example, if the IP address of your computer is 192.168.0.1/255.255.255.0, assigning
+192.168.2.1/255.255.255.0 to the router makes no sense, because the TFTP upload will
+fail.
+
+###### "IP address of X has changed. Please assign a static IP to the interface."
+
+This can happen if the network interface in question automatically detects that
+the network cable has been connected, and your computer tries to reconfigure that
+interface (NetworkManager on Linux does this for example) - this can usually be
+disabled.
+
+An alternative would be to add `-c 'ifconfig <interface> <ip>'` to the command line,
+for example:
+
+`# nmrpflash -i eth0 -a 192.168.1.1 -f firmware.bin -c 'ifconfig eth0 192.168.1.2'`
+
+This will execute the command specified by `-c` prior to starting the TFTP upload (in
+this case setting the IP address to 192.168.1.2).
+