Brocade BigIron RX Series Configuration Guide User Manual
Page 276
198
BigIron RX Series Configuration Guide
53-1002484-04
Configuring forwarding parameters
7
•
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
•
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 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.
BigIron RX(config)# no ip source-route
Syntax: [no] ip source-route
To re-enable forwarding of source-routed packets, enter the following command.
BigIron RX(config)# ip source-route
Enabling support for zero-based IP subnet broadcasts
By default, the device treats IP packets with all ones in the host portion of the address as IP
broadcast packets. For example, the device treats IP packets with 209.157.22.255/24 as the
destination IP address as IP broadcast packets and forwards the packets to all IP hosts within the
209.157.22.x subnet (except the host that sent the broadcast packet to the device).
Most IP hosts are configured to receive IP subnet broadcast packets with all ones in the host
portion of the address. However, some older IP hosts instead expect IP subnet broadcast packets
that have all zeros instead of all ones in the host portion of the address. To accommodate this type
of host, you can enable the device to treat IP packets with all zeros in the host portion of the
destination IP address as broadcast packets.
NOTE
When you enable the device for zero-based subnet broadcasts, the device still treats IP packets with
all ones the host portion as IP subnet broadcasts too. Thus, the device can be configured to support
all ones only (the default) or all ones and all zeroes.
NOTE
This feature applies only to IP subnet broadcasts, not to local network broadcasts. The local network
broadcast address is still expected to be all ones.
To enable the device for zero-based IP subnet broadcasts in addition to ones-based IP subnet
broadcasts, enter the following command.
BigIron RX(config)# ip broadcast-zero
Syntax: [no] ip broadcast-zero