Conference netcad::hub_mgnt

AB-00-00-02-00-22 is the multicast address that MOP uses to send
periodic SYSID announcements.  The DECnet MOP architecture requires
that these be sent every 5 minutes.  They tell what kind of device
is on the LAN, what MOP functions it supports, and other optional
info more relevant to DECnet nodes.  I don't think you can turn
them off, even if they aren't relevant to your network.

	Dotsie

    The DECswitches (&DECbridges) etc. will originate periodic MOP sysid's
    as well as respond to MOP sysid requests. The information in these MOP
    packets includes the hardware address of the link, device type, hardware
    version, ROM version etc. There are additional parameters sent out in an 
    802 sysid, and for an FDDI datalink.
    These sysid's must originate from each port having a separate hardware
    address, and the bridges must forward sysid's from any port out to all
    other ports in order to allow these messages to be sent to all LANs.
    There are two types of sysid's, Ethernet MOPv3 Phase IV and 802.3 MOPv4
    Phase V, or FDDI format.
    
    Bob
    

    re .1/.2,
    
    thanks for your quick response!
    
    But I still have a question, since we are not managing the DEChub900
    modules via MOP (not all), we use SNMP (Polycenter Netview), so I do
    not see any reason why these DEChub900 modules still sending the MOP
    sysid messages (may be I do not understand), if we filter the MOP
    sysid messages on gigaswitches (since DS900EFs are connected via
    couples of gigaswitches (in FDDI tree), what are the impact to customer
    network (sure they want LAT, from DS900TM to VAX/AXP hosts)?
    
    thanks again for help!
    Andrew Chiu - Network Services Sydney 

    Does your customer have any nodes running DECNET? If so then
    the sysid's are important to these nodes. If not, what's the 
    big deal??? These MOP messages get sent out every 5 minutes 
    if not less frequent. I don't understand why they really need 
    to be supressed.
    The bottom line is the MOP Sysid messages sent out by the DS900EF's
    I don't believe can be turned off. In terms of managing the HUB
    modules in question using SNMP (Polycenter Netview), the MOP Sysid's 
    have no relationship to being managed. Ignore them, it's not a big
    deal. They are a requirement for proper Ethernet operation in a
    DECNET environment, and should have absolutely no impact on your
    customers network or ability to use Polycenter Netview.
    
    
    Bob

    Hi,
    
    I have  a customer with similar configuration: 2 Gigaswitches, 20
    DEChub 900, 40 DECswitch 900, 100+ DECrepeaters. The customer has seen
    the MOP messages and he's complaining about them. I've told him that
    it is not much traffic, it is not important, etc. but he doesn't
    understand why he has to have MOP in a complete TCP/IP network: Only
    Windows NT servers and PC-Windows clients with LAN_MAnager over TCP/IP
    (no VAX's).
    
    The problem is not the amount of traffic, but the fact of having
    one not-needed protocol from a Network Management point of view.
    
    I understand the complaint from the customer, so I would like to know
    how could I deactivate those messages.
    
    Any hint from the experts?
    
    Thanks in advance,
    
    Jose 
    Network Services Spain

Hi,

Since MOP sysid's are a requirement of Digital Network Architecture
for any LAN devices (whether running DECnet or not), they have been
built into Digital products for the last ten years or so.  There is no
way to turn them off, other than to have new releases of the products.

It is valid to question why they are needed anymore, and it is valid
to request that they be customer configurable.  Digital's own network
has tools that collect sysid's and use the info for troubleshooting,
but it does seem reasonable that they could be turned off.

	Dotsie