In Australia, Labour Market Testing (LMT) is a mandatory process that requires employers to prove they have genuinely attempted to recruit a local worker before sponsoring an overseas candidate.
You must conduct Labour Market Testing if you are nominating a worker for:

You must provide evidence of at least two (2) separate advertisements.
To satisfy the Labour Market Testing (LMT) criteria, your advertisements must meet two specific time constraints:
1. The 4-Week Rule (Duration) The advertisement must be live and viewable to the public for a minimum of 4 consecutive weeks (28 calendar days).
2. The 4-Month Rule (Validity Window) The advertising must have been conducted within the 4 months immediately before you lodge the nomination application.
Note: the nominated position may be advertised in the same medium (such as newspaper advertisements, on two separate occasions) or in any two different mediums simultaneously, or on two separate occasions
To satisfy the Department of Home Affairs, your advertisements must be published on platforms with national reach that are standard for your industry. You must use at least two distinct platforms from the acceptable list below.
The most common and safest method is to use prominent, national recruitment websites. Examples include:
Do not use these platforms. The Department of Home Affairs does not consider them to be professional recruitment sites with national reach.
Advertising of the nominated position must meet all of the below:
If you are applying under a DAMA, the timing rules for advertising are different from the standard visa stream.
LMT Exemptions applies in the following circumstances:
Note: the above ITO exemptions do not apply for nominations lodged under a labour agreement and the Skilled Employer Sponsored Regional (Provisional) visa (subclass 494).
There is no mandatory Labour Market Testing (LMT) requirement for the Subclass 186 visa. However, it is recommended that employers undertake LMT to demonstrate genuine efforts to recruit suitably qualified Australian workers before nominating an overseas candidate.
Not really, Labour Market Testing does not necessarily need to be conducted on a single occasion.
Yes, it is acceptable to publish salary range. (for example: AUD70,000 – AUD80,000)
LMT is not required if it would conflict with Australia’s international trade obligations, or where the annual earnings of the applicant will be equal to or greater than $250,000.