Brocade Multi-Service IronWare Switching Configuration Guide (Supporting R05.6.00) - Manual (Page 809)

Multi-Service IronWare Switching Configuration Guide 779
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Configuring forwarding parameters
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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.
Brocade(config)# ip directed-broadcast
Syntax: [no] ip directed-broadcast
The software makes the forwarding decision based on the device'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.
Brocade(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.
Brocade(config)# interface ethernet 1/1
Brocade(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 Brocade device supports both types of IP source routing:
• Strict source routing – requires the packet to pass through only the listed routers. If the
Brocade device receives a strict source-routed packet but cannot reach the next hop interface
specified by the packet, the Brocade device discards the packet and sends an ICMP
Source-Route-Failure message to the sender.
NOTE
The Brocade device allows you to disable sending of the Source-Route-Failure messages. Refer
to
“Disabling ICMP messages” on page 781.
• Loose source routing – requires that the packet pass through all of the listed routers but also
allows the packet to travel through other routers, which are not listed in the packet.
The Brocade device forwards both types of source-routed packets by default. You cannot enable or
disable strict or loose source routing separately.
To disable forwarding of IP source-routed packets, enter the following command.
Brocade(config)# no ip source-route
Syntax: [no] ip source-route
To re-enable forwarding of source-routed packets, enter the following command.
Brocade(config)# ip source-route