Conference 7.286::fddi

1700.0. "DB610 filtering using DECmcc." by BWTEAL::W_MCGAW () Wed May 31 1995 18:02

    Hi,
    
    I have a customer that has questions on filtering for a DB610.  He has
    three ports currently in use.  Port 1 is to an FDDI ring with a large
    amount of TCPIP traffic on it.  Port 2 supports an Ethernet with
    production PDP11's which experience a lot of grief when tcpip traffic
    gets on the wire and port 3 supports an office work area that also uses
    TCPIP.  They wanted to route the tcpip traffic between ports 1 and 3
    but not port 2.
    
    He tried doing this with DECmcc by issuing the following command:
    
        SET BRIDGE 'bridge-name' FORWARDING DATABASE MULTICAST ENTRY
    FF-...-FF FORWARD PORTS (1,3,3,1)
    
    This command didn't take and didn't give an error.  The customer then
    realized that he had to remove the all FF's multicast entry before he
    could set the ports to forward.  He used the MCC toolbox to remove the
    entry and issued the set bridge command again.  This time it worked. 
    As a result of these commands, port 2 was allowing all of the tcpip
    traffic through to the PDP11's.  They all eventually locked up.  He
    cleared the problem by doing a SET DISPOSITION=FORWARD on the bridge. 
    How could he have avoided this problem?  Is there a better way to
    accomplish blocking of TCPIP traffic on port 2 only?
    
    Thanks,
    Walt