How effective is ifdown and ifup for changing netowrk settings

[brucexx]

I know that it does the job but how effective it is ? Should I expect any problems if I just change the etc/network/interfaces file and do ifdown/ifup ?

Should I first bring the interface down ifdown make the change and bring it back up ifup or it does not matter ?

Thank you

 

[gosha]

It does not matter, because the changes in /etc/network/interfaces will affect only during UP interface (after down).