UDP Broadcast Forwarding

Typically, broadcast packets from one interface are not forwarded (routed) to another interface. However, some applications use UDP broadcasts to detect the availability of services, and some protocols, such as BOOTP/DHCP, require broadcast forwarding to provide services to clients on other subnets. Configuring UDP broadcast forwarding on the S- K- and 7100-Series device involves enabling it for one or more protocols, and assigning IP helper addresses as described in this section.

Use the ip forward-protocol command in configuration command mode to enable UDP broadcast forwarding for the specified port. The following keywords are supported for common UDP ports:

• bootps — Specifies the Bootstrap Protocol server (67) port
• domain — Specifies the Domain Name Service (53) port
• nameserver — Specifies the IEN116 name service (42) port
• netbios-dgm — Specifies the NetBIOS datagram service (138) port
• netbios-ns — Specifies the NetBIOS name service (137) port
• tacacs — Specifies the Terminal Access Controller Access Control System (49) port
• tftp — Specifies the Trivial File Transfer Protocol (69) port
• time — Specifies the Time (37) port