When it comes to interface naming, vEth0 should be considered a reserved name.

For full support/identical naming inside the firewall, interface names should match the below regular expression. The current limit is 26 characters.

[a-zA-Z][a-zA-Z0-9_-]{,14}

A few other characters might work, but the interface will have a name without those characters inside the firewall (in the firewall's configuration), possibly with other modifications as well to make them unique in this context.

Whitespace or any of the below characters in the interface names are known to cause problems and are therefore unsupported. Other characters, except those in the first paragraph, are used at your own risk.

/ : " ' , = [ ; %