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Conference netcad::hub_mgnt

Title:DEChub/HUBwatch/PROBEwatch CONFERENCE
Notice:Firmware -2, Doc -3, Power -4, HW kits -5, firm load -6&7
Moderator:NETCAD::COLELLADT
Created:Wed Nov 13 1991
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:4455
Total number of notes:16761

3785.0. "Decswitch filtering" by BELFST::belcoo.bvo.dec.com::HOUSTON (Peace at last) Fri Aug 09 1996 12:09

Hello

This is a DECswitch filtering problem.

I cannot get the filtering on my DECSWITCH to work the way I want !

Basically I have two LANS that I want to connect using ports 1 & 2 on the 
DECSW.

I want address filtering to only allow a few selected station addresses 
access from LAN1 on port1 to LAN2 on port 2 and vice versa. Port 2 is 
configured onto the Dechub backplane. Port 1 connects to LAN1.

I have experimented using my Hubwatch PC which is on LAN1. I set up an 
address filter with my PC's ethernet address to enable the station address 
on port's 1 and 2.

However when I change the unspecified filters to "red" for ports 1 and 2
I loose my connection to the hub. 

So the unspecified default has worked and no packets are passed between the 
two LANS.

However the filter for my PC should have allowed me to keep my Hubwatch 
connection.

I suspect it may be multicast addresses or something. Can anyone help with 
this problem ?

Regards,

Colin
T.RTitleUserPersonal
Name
DateLines
3785.1NPSS::RAUHALATue Aug 13 1996 13:372
    It sounds to me like you need to enter the source and destination,
    including multicast destination addresses.
3785.2NPSS::WADENetwork Systems SupportTue Aug 13 1996 15:5315
    
    Being that the PC is on port 1 there is no need to allow the PC address
    to be seen on port 2.  Adding a filter entry for the MAC address of the
    PC to be allowed on port 1 is all you need on that end.  
    
    My guess is that the IP services module is not the DECswitch and it is
    connected through port 2 of the DECswitch.  So you need to add a filter 
    entry for the MAC of the IP services module to be allowed on port 2.
    
    Just a guess.....
    
    Bill
    
    
    
3785.3MAC addressesBELFST::belcoo.bvo.dec.com::HOUSTONPeace at lastFri Aug 16 1996 08:0222
Hello again.

Thanks for the help so far. I now have it working.

My problem was not appreciating the real difference between the physical address and the 
MAC address.

Also reply 2 was quite correct. I needed to enter a filter specifying the MAC address of 
the IP services module on port 2. Once this was done I regained my SNMP path to the 
services module and Hubwatch management of the Portswitch !

For filters to work correctly then the proper MAC address has to be entered for the 
workstation in question. Some protocols like Decnet use a modified MAC address while 
others like IP use the physical address. A station with IP and Decnet returns the 
modified MAC address because modifying protocol takes priority ? Am I correct in saying 
this ?

Does anyone know whether NETBEUI modifies the MAC address ?

Best regards,

Colin
3785.4<-- RE: NetBEUI protocol...NETCAD::BATTERSBYFri Aug 16 1996 10:2712
    
    >> Does anyone know whether NetBEUI modifies the MAC address ?
    
    Well, NetBEUI being a non-routable protocol will be missing 
    information in the frame header that provides routing information
    to identify separate logical LANs. I'd have to go out to the lab
    and look at a NetBEUI packet to verify that source & destination
    MAC addresses are intact, but I suspect that they are not altered
    by the NetBEUI protocol.
    If I may ask, what prompted you to ask this question?
    
    Bob
3785.5Netbeui problemBELFST::belcoo.bvo.dec.com::HOUSTONPeace at lastThu Aug 29 1996 11:3415
Hello.

The reason for the NETBEUI question is that I have created a filter on port 1 to allow an NT 
workstation. On port 2 I have created a filter to allow a VMS Pathworks server. The default for 
unspecified addresses is "do not allow".

Subsequently the workstation has IP connections to the PAthworks server but no NETBEUI 
connections ?

I have also not set up any protocol filtering so I cannot understand why the workstation cannot 
browse the Pathworks shares as before.

Any ideas ?

Colin
3785.6Netbeui multicast needed ?BELFST::belcoo.bvo.dec.com::HOUSTONPeace at lastFri Aug 30 1996 08:4719
Hello.

With respect to reply 5 and the Netbeui problem I have noticed the following 
behaviour.

With address filters set up to enable , one for the NT workstation, and one for 
the Pathworks server I only seem to have IP access to the Server. Netbeui browsing 
facility does not work.

Remove unspecfiied filter defaults and the Netbeui browing facility works between 
the workstation and the server.

Then re apply the unspecified default filtering, having previously established a 
network drive connection to the server, from the client. It still works !

Why does the Netbeui appear to show this different behaviour as compared to IP ?
Perhaps it is a multicast but does anyone know what it is ?

Colin