Login restriction by IP

RouterOS Beginner Basics
1

Hi,
I don’t understand the following syntax. What does the 0 there represent? Is it a username or what?
https://wiki.mikrotik.com/wiki/Manual:Securing_Your_Router#Access_by_IP_address
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Access by IP address
Besides the fact that default firewall protects your router from unauthorized access from outer networks, it is possible to restrict username access for the specific IP address

/user set 0 allowed-address=x.x.x.x/yy
x.x.x.x/yy - your IP or network subnet that is allowed to access your router.
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And what does the sentence “it is possible to restrict username access for the specific IP address” really mean? Can one access (ie. login) also without a username?
And: is this a per user setting or is it valid for all users?
And of course: how can I view the current status of this setting?
Thx

2
  1. https://wiki.mikrotik.com/wiki/Manual:Console#Item_Numbers
    2a. It means that this user is allowed to login only from the specified IP address(es) and no others.
    2b. No.
  2. Each user can have a specific set of IP addresses, there is no global setting short of constructing firewall rules that would prohibit logins.
  3. /user print
3

@macsrwe Thx, got it now. Btw, in the latest beta (7.0beta5) the syntax seems to have slightly changed: “allowed-address” changed to just “address”, and it accepts besides usernumber also username.