How to set Tag = 0x00 in Tunnel-Private-Group-ID attribute

Alan DeKok aland at
Tue Sep 24 20:12:03 CEST 2019

On Sep 24, 2019, at 1:46 PM, Phani Siriki <yvsg.phanis at> wrote:
> Is there a way to set "Tag = 0x00" in Tunnel-Private-Group-ID attribute?

  Not really/

> I have the following user listed in users file. When access-accept is
> sent, tag-id is set to 0x00 in Tunnel-Medium-Type and Tunnel-Type
> attributes. RFC 2868 didn't mention anything about tag=0x00

  No, it says this explicitly:

      The Tag field is one octet in length and is intended to provide a
      means of grouping attributes in the same packet which refer to the
      same tunnel.  Valid values for this field are 0x01 through 0x1F,
      inclusive.  If the Tag field is unused, it MUST be zero (0x00).

> and I
> assume thats the reason we are not sending it from Freeradius.

  What does that mean?  Tunnel-Type is defined to be 4 octets long.  1 for the tag, and 3 for that value.

  Are you seeing Tunnel-Type sent as 3 octets?

  When the server prints the attributes in debug output, it omits the tag if it's zero.  It doesn't print an explicit ":0" after the attribute name.

  Perhaps you could explain what you're trying to.  Right now, you're asking "why is there a problem" when no problem exists.

  Alan DeKok.

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