Riverstone Networks WICT1-12 - Manual (Page 186)

11-8 Riverstone Networks RS Switch Router User Guide Release 8.0
Configuring IP Services (ICMP) IP Routing Configuration Guide
To configure three DNS servers and configure the RS’s DNS domain name to “mrb.com”:
11.7 CONFIGURING IP SERVICES (ICMP)
The RS provides ICMP message capabilities including ping and traceroute. The
ping
command allows you to
determine the reachability of a certain IP host, while the
traceroute
command allows you to trace the IP gateways
to an IP host.
11.8 CONFIGURING IP HELPER
The
ip helper-address
command allows the user to forward specific UDP broadcast from one interface to another.
Typically, broadcast packets from one interface are not forwarded (routed) to another interface. However, some
applications use UDP broadcast to detect the availability of a service. Other services, for example BOOTP/DHCP
require broadcast packets to be routed so that they can provide services to clients on another subnet. An IP helper can
be configured on each interface to have UDP broadcast packets forwarded to a specific host for a specific service or
forwarded to all other interfaces.
You can configure the RS to forward UDP broadcast packets received on a given interface to all other interfaces or to
a specified IP address. You can specify a UDP port number for which UDP broadcast packets with that destination port
number will be forwarded. By default, if no UDP port number is specified, the RS will forward UDP broadcast packets
for the following six services:
• 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 six default UDP services:
To forward UDP broadcast packets received on interface int2 to the host 10.2.48.8 for packets with the destination port
111 (port mapper):
To forward UDP broadcast packets received on interface int3 to all other interfaces:
rs(config)# system set dns server “10.1.2.3 10.2.10.12 10.3.4.5” domain
mrb.com
rs(config)# ip helper-address interface int1 10.1.4.5
rs(config)# ip helper-address interface int2 10.2.48.8 111
rs(config)# ip helper-address interface int3 all-interfaces