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Robert4

macrumors 6502a
Original poster
Apr 20, 2012
638
30
Hello,

Have a mac desktop running Sonoma.

Line comes into the house to a Comcast Modem, then a Router.

Question: I have a shortwave radio that "talks" to a program on my mac.
For ther program to work, I need the correct radio IP address.

No problem, but it keeps changing.

There was a msg that popped up that it is possible to have the Router always lock and use the same
IP Address for the radio.

Can't figure out where in the mac settings I would do this.

Any thoughts on ?

Thanks,
Bob
 

Fishrrman

macrumors Penryn
Feb 20, 2009
29,239
13,309
Does the radio have a "hardware address" (or "IP address") of some sort?
It might be near wherever the radio's serial number is. On the bottom, etc.

Can the software you have be set up to look for that specific address?

Does the radio have an ethernet port?
I'm thinking you would connect that to one of the LAN ports on the router.

Is there documentation for the radio?
If not in printed form, perhaps available "on the net" as a pdf?
Anything on YouTube about that particular radio?
 

BrianBaughn

macrumors G3
Feb 13, 2011
9,837
2,504
Baltimore, Maryland
The router's firmware probably has the ability to assign a "static lease" to devices based on their ethernet (MAC) address. This would be the best place to do it.

What do you have…WiFi, ethernet or both…connected to the router's local network?
 
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Weaselboy

Moderator
Staff member
Jan 23, 2005
34,481
16,194
California
This can be configured in your raouter, as @BrianBaughn mentioned.

Search your router manual for "IP reservation" to set this up. The setting will tell the router to look for the devices MAC address and set a designated IP address to that device. The MAC address will look like this d8:fb:d6:a4:4f:93 format.
 
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Alameda

macrumors 65816
Jun 22, 2012
1,276
870
To be clear, your shortwave radio needs to be configured with a static IP address, instead of being configured to use DHCP (in which your home router assigns the radio an IP address.)

Many routers have a DHCP “range,” which are the addresses that will be assigned to devices on your home network. This consists of four three-digit numbers, often:
192.168.1.x, where ‘X’ is a range from 0-255.

Each 3-digit number ranges from 0-255. Do not change the first three numbers, only the last.
If the DHCP range is 192.168.1.[3-127], then you can assign your radio a static address from 128-255, without conflict. So pick 192.168.1.128 and you’ll be fine.


I hope this is clear enough; I know it can be confusing.
 

dwig

macrumors 6502a
Jan 4, 2015
908
449
Key West FL
To add to the confusion, there are two methods to solve this. Your router and/or your radio may limit you to one or the other:

  • IP Reservation - this is done by letting the radio get a random IP address from the router DHCP server function and then you telling the router to reserve this IP address for the radio's MAC address. The radio thinks it's getting a dynamic IP address from the DHCP server, but it always gets the same address.
  • Fixed IP - this requires you to limit the range of IP addresses served by the router's DHCP, usually an easy thing to do, and to configure the radio to manually use an IP address outside of the router's DHCP address range. You radio may or may not have this ability.
 
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