Clients sending corrupt VendorClassID

Randall C Grimshaw rgrimsha at
Tue Aug 21 16:32:05 UTC 2012

Subject: Clients sending corrupt VendorClassID
Revised: Clients sending NULL in VendorClassID

In my dhcpd.conf I log on commit and in some cases use the vendor-class-identifier in class matching definitions.

I am seeing PS3 devices submit a control value that is affecting the log and class definitions.

Vendor-Class Option 60, length 4: "PS3^@"

The NULL character (code 0) is represented by Ctrl-@, "@" being the code immediately before "A" in the ASCII character set. For convenience, a lot of terminals accept Ctrl-Space as an alias for Ctrl- at . In either case, this produces one of the 32 ASCII control codes between 0 and 31.

It seems I could use a good stringCleaning function or at least a chomp.... or a 'safe text' filter setting

Does anyone know an available solution to this

Thank you.

on commit {
  log( error,
    concat( "This is an example of: ",
      pick-first-value(option vendor-class-identifier,"no-identifier"),
      " this text is missing from the logs"

Randall Grimshaw rgrimsha at
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