Enabling Forwarding Of Directed Broadcasts - Dell PowerConnect B-RX Configuration Manual

To modify the TTL threshold to 25, enter the following commands.
BigIron RX(config)# ip ttl 25
Syntax: ip ttl <1-255>

Enabling forwarding of directed broadcasts

A directed broadcast is an IP broadcast to all devices within a single directly-attached network or
subnet. A net-directed broadcast goes to all devices on a given network. A subnet-directed
broadcast goes to all devices within a given subnet.
NOTE
A less common type, the all-subnets broadcast, goes to all directly-attached subnets. Forwarding for
this broadcast type also is supported, but most networks use IP multicasting instead of all-subnet
broadcasting.
Forwarding for all types of IP directed broadcasts is disabled by default. You can enable forwarding
for all types if needed. You cannot enable forwarding for specific broadcast types.
To enable forwarding of IP directed broadcasts, enter the following command.
BigIron RX(config)# ip directed-broadcast
Syntax: [no] ip directed-broadcast
Brocade software makes the forwarding decision based on the router's knowledge of the
destination network prefix. Routers cannot determine that a message is unicast or directed
broadcast apart from the destination network prefix. The decision to forward or not forward the
message is by definition only possible in the last hop router.
To disable the directed broadcasts, enter the following command in the CONFIG mode.
BigIron RX(config)# no ip directed-broadcast
To enable directed broadcasts on an individual interface instead of globally for all interfaces, enter
commands such as the following.
BigIron RX(config)# interface ethernet 1/1
BigIron RX(config-if-e10000-1/1)# ip directed-broadcast
Syntax: [no] ip directed-broadcast
Disabling forwarding of IP source-routed packets
A source-routed packet specifies the exact router path for the packet. The packet specifies the path
by listing the IP addresses of the router interfaces through which the packet must pass on its way to
the destination. The device supports both types of IP source routing:
•
BigIron RX Series Configuration Guide
53-1001810-01
Strict source routing – requires the packet to pass through only the listed routers. If the device
receives a strict source-routed packet but cannot reach the next hop interface specified by the
packet, the device discards the packet and sends an ICMP Source-Route-Failure message to
the sender.
NOTE
The device allows you to disable sending of the Source-Route-Failure messages. Refer to
"Disabling ICMP messages"
Configuring forwarding parameters
on page 188.
7
187