How do I add unique incrementing "dummy" data to a query in Oracle SQL?

Let's say that I am working with a table and all that I want out of that actual table is a single column. I will want to use dummy values for additional columns, but they have to be unique and incrementing numbers.

I want a result something like this:

I've found solutions that seem close when searching through other similar questions, but those seemed to do weird things like repeating the same MAC once for each dummy value, for example. I just want a single row per MAC address, and a unique value in my dummy value columns.

Database programming outside of your standard queries is basically foreign to me.

I tried a query like this, but it had strange outputs with the previously mentioned repeating data and non-unique values.

SELECT MAC_ADDR, CONCAT('test-','001' + LEVEL) AS DUMMY_VALUE FROM MAC_ADDRESS_TABLE CONNECT BY LEVEL <= 5;

Use the ROWNUM pseudo-column and format it using TO_CHAR:

SELECT MAC_ADDR,
       'test-' || TO_CHAR(ROWNUM, 'FM000') AS DUMMY_VALUE
FROM   MAC_ADDRESS_TABLE;

Which, for the sample data:

CREATE TABLE MAC_ADDRESS_TABLE ( MAC_ADDR ) AS
SELECT '64:16:7F:64:94:1A' FROM DUAL UNION ALL
SELECT '64:16:7F:0B:EB:9F' FROM DUAL UNION ALL
SELECT '64:16:7F:5C:99:3F' FROM DUAL UNION ALL
SELECT '64:16:7F:23:7C:C8' FROM DUAL UNION ALL
SELECT '64:16:7F:3B:4A:A6' FROM DUAL;

Outputs:

If you want the table ordered before numbering then you can use:

SELECT MAC_ADDR,
       'test-' || TO_CHAR(ROWNUM, 'FM000') AS DUMMY_VALUE
FROM   (SELECT * FROM MAC_ADDRESS_TABLE ORDER BY mac_addr);

or:

SELECT MAC_ADDR,
       'test-'
       || TO_CHAR(ROW_NUMBER() OVER (ORDER BY mac_addr), 'FM000') AS DUMMY_VALUE
FROM   MAC_ADDRESS_TABLE;

Which both output:

fiddle