External Network Scanning?

[Whoop]

Hi all,

I've been asked to perform a external scan of the network perimeter to check for vulnerabilities but my tin-foil hat knowledge is slim!

Is there a good company I should approach for this or is there a piece of software someone can recommend? It's rather ambiguous to me how thorough it needs to be... (I guess it's not like my old sub7 days ) but I'll need to generate a report off it. Thanks.

 

[Whoop]

Thanks everyone, without an actual scope they don't make it an easy task.

I'll take a look at all the stuff suggested so far.