yes has to be in same group

http://www.symantec.com/connect/forums/multiple-gup-sepmr5

Best practices for Group Update Provider (GUP) from Symantec Endpoint Protection MR3 or earlier builds

http://service1.symantec.com/support/ent-security.nsf/854fa02b4f5013678825731a007d06af/230d1cf8e23d01e2882574a90062d485?OpenDocument

Thanks Pra

As Prachand pointed out there were major changes with RU5 and I have not personally had a chance to test all of them out.

Prior to RU5  you needed atleast on client in the group with the GUP to force it to activate and pull definitions down.    This also would be what caused the updated definitions to pull down too.   Once activated machines from other groups could be made to point to it because it was alread a GUP.  Works but doesnt sound like it will do what your wanting to do.   I will have to test out what Prachand says yet and see if it works as I am using a sever as my gup and would prefer to have it following a different scan schedule than it is now.

GUP can be part of different group, but it needs to be in same LAN as that of client takingthe updates from GUP.

Check this

https://www-secure.symantec.com/connect/articles/configuring-group-update-providers-symantec-endpoint-protection-110-ru5

https://www-secure.symantec.com/connect/articles/types-group-update-providers-ru5-release-symantec-endpoint-protection-110

And these Videos

https://www-secure.symantec.com/connect/videos/group-update-providers-part-1

https://www-secure.symantec.com/connect/videos/group-update-providers-part-2

Its all fine, answered perfectly.

Was having an issue with a GUP that I had grouped outside of the main group.

But is working fine - yes, we are using RU5 and muktple GUP options.

NOTE - THEY DO NOT BEED THE SAME GROUP.

THEY HOWEVER DO NEED TO BE IN THE SAME POLICY AS THE DESKTOPS I.E. WHERE THE GUPS ARE DEFINED

If they are not in the same policy, they will not appear in the globalist.xml and hence SEPM cannot tell the clients to use GUP xxxx...etc

GUPs do not have to be in the same group.

Example - you have a group that contains a bunch of systems that you would like to act as GUPs for other groups.  Typically, this occurs if you are using AD sync for group management.  You create an LU  policy for that group which specifies "localhost" as the GUP.  This makes all clients in that group a GUP.  You can then apply an LU policy to other groups which refer to one or more of the GUPs in your GUP group.  Simple and it works - RU5 or earlier.