Create Table #t (server sysname, dts sysname);

Declare @server sysname
Declare c Cursor
read_only
for
	select data_source from sys.servers where is_linked = 1 or data_source = @@servername
open c
fetch next from c into @server
while @@fetch_status = 0
begin
	insert #t
	EXEC ('SELECT ''' + @server + ''', name FROM [' + @server + '].msdb.dbo.sysdtspackages')
	fetch next from c into @server
end
close c
deallocate c

select distinct server from #t
drop table #t