SmartSwitch Router User Reference Manual 85Chapter 8: IP Routing Configuration Guide• BOOTP/DHCP (port 67 and 68)• DNS (port 37)• NetBIOS Name Server (port 137)• NetBIOS Datagram Server (port 138)• TACACS Server (port 49)• Time Service (port 37)To forward UDP broadcast packets received on interface int1 to the host 10.1.4.5 for the sixdefault UDP services:To forward UDP broadcast packets received on interface int2 to the host 10.2.48.8 forpackets with the destination port 111 (port mapper):To forward UDP broadcast packets received on interface int3 to all other interfaces:Configuring Direct BroadcastDirected broadcast packets are network or subnet broadcast packets which are sent to arouter to be forwarded as broadcast packets. They can be misused to create Denial OfService attacks. The SSR protects against this possibility by not forwarding directedbroadcasts, by default. To enable the forwarding of directed broadcasts, use the ip enabledirected-broadcast command.You can configure the SSR to forward all directed broadcast traffic from the local subnet toa specified IP address or all associated IP addresses. This is a more efficient method thandefining only one local interface and remote IP address destination at a time with the ip-helper command when you are forwarding traffic from more than one interface in thelocal subnet to a remote destination IP address.To enable directed broadcast forwarding on the “int4” network interface:ssr(config)# ip helper-address interface int1 10.1.4.5ssr(config)# ip helper-address interface int2 10.2.48.8 111ssr(config)# ip helper-address interface int3 all-interfacesssr(config)# ip enable directed-broadcast interface int4
