Firewall rules for Business Communications Manager with Dialup interfaces 831Programming Operations GuideFirewall rules for Business Communications Manager withDialup interfacesFor systems with dialup interfaces (ISDN, V.90), we recommend that you add Firewall filters toall interfaces except the dialup interface that blocks NetBIOS traffic. This prevents any NetBIOSpackets from getting into the Business Communications Manager and bringing up the dialupinterface link.For example, if a Business Communications Manager is configured with two LANs and one ISDNdialout interface, then these Firewall rules should be placed on both of the LANs.Table 263 Input Rule Configuration for systems with dialup interfacesIR1Direction: InStateful: YesDisposition: BlockProtocol: TCP/UDPSource IP: 0.0.0.0Source Mask: 0.0.0.0Source Port: NETBIOSDestination IP: 0.0.0.0Destination Mask: 0.0.0.0Destination Port: NETBIOSIR2Direction: InStateful: YesDisposition: BlockProtocol: TCP/UDPSource IP: 0.0.0.0Source Mask: 0.0.0.0Source Port: NETBIOSDestination IP: 0.0.0.0Destination Mask: 0.0.0.0Destination Port: DNS
