For both Flexnet and DSLS: Run abaqus whereami to get the Site ID.
Look at the Abaqas.dat file.
Flexnet Keys: Look for SN value in license file and that is the Site ID.
DSLS: The DSLS license file is a ZIP archive that normally has an extension of .LICZ. Extract the files from the DSLS license file. You should have a series of files named FEAT-n-of-x.LIC. Open the first one in a text editor, and look for a line that starts with CustomerId. The line contains the siteID value.