I am currently attempting to set the in-interface (and out-interface) of a Firewall NAT rule to blank. In WinBox, all you have to do is set the combobox to the blank option to achieve this. My solution requires using the api/terminal so I don't have the luxury of WinBox.

For example's sake, to set a port to blank, you send the value "0," and the router stores "" as the port. In addition, to set an ip-address to blank, you would pass "0.0.0.0," and the router often stores that as blank. Any time unit stored as a blank is set by passing a "0."

What is the "blank" keyword for interfaces (or in-interface, out-interface)? I have tried:
0, -1, all, none, null, no, n

All results return the same "input does not match any value of interface" error. If I submit a blank value, I get an "ambiguous" error. All I want to do is intentionally set in-interface/out-interface to blank.

The only way to leave it blank is to never send a value. I want to use an automated process to create firewall rules and I don't want to have to fine tune eight functions (4 for add, 4 for edit) when I can use just one.

Thanks for the help in advance,
Scott

unset ?

That's what I'm using for my workaround at this time. I have a function that adds/edits rules and does not modify the sensitive ones (like in-interface). If applying a value, set it, otherwise unset. Seems like the only solution at this point.

Good minds think alike, eh?
Thank you for your input on this.

unset is not a workaround.

either you set your value, that you think is default, or unset variable.

Janisk, so you're saying:
There is not way to set the in-interface to blank, only to set it to an actual interface (ex. ether1), or just never set it at all. Should I want to clear it, I still cannot set it to blank, I can only unset. It's not a workaround, it's the only way.

Sorry, but your comment was short so I needed to clarify

what is API syntax for 'unset'?

If the menu allows for unset, here is the api structure for it:
/.../unset=numbers=[api id numbers sep. by comma]=value-name=[field to unset]

for example
/ip/firewall/nat/unset=numbers=*1=value-name=dst-address
/ip/firewall/nat/unset=numbers=*1,*4=value-name=hotspot

Some menus will not allow it. For example, the /ip/address/ section does not contain a definition for unset.

Hope this helps.

(EDITED- Forgot to include "unset" command in my example)

wow! It's working, thanks =)

Sorry for bringing up this topic, but I’m currently trying to do the same: set in-interface to none for many dstnat rules via console. set X in-interface=“” doesn’t work. Is there still no way unsetting it without using api style workarounds?

where 123 is rule number from 'print' command

I've accidentally found it on my own, but anyway thanks Chupaka. You're as always helpful

Just put ! before the element that you want to be blank

check out this example where here I want to put blank value to "check-gateway" so it will be like this "!check-gateway" :