Brocade Communications Systems Layer 3 Routing Configuration ICX 6650 User Manual
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Brocade ICX 6650 Layer 3 Routing Configuration Guide
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Configuring IP parameters – Layer 3 Switches
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Strict source routing – requires the packet to pass through only the listed routers. If the Layer 3
Switch receives a strict source-routed packet but cannot reach the next hop interface specified
by the packet, the Layer 3 Switch discards the packet and sends an ICMP Source-Route-Failure
message to the sender.
NOTE
The Layer 3 Switch 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 Layer 3 Switch forwards both types of source-routed packets by default. To disable the feature,
use either of the following methods. You cannot enable or disable strict or loose source routing
separately.
To disable forwarding of IP source-routed packets, enter the no ip source-route command.
Brocade(config)# no ip source-route
Syntax: [no] ip source-route
To re-enable forwarding of source-routed packets, enter the ip source-route command.
Brocade(config)# ip source-route
Enabling support for zero-based IP subnet broadcasts
By default, the Layer 3 Switch treats IP packets with all ones in the host portion of the address as IP
broadcast packets. For example, the Layer 3 Switch treats IP packets with 192.168.22.255/24 as
the destination IP address as IP broadcast packets and forwards the packets to all IP hosts within
the 192.168.22.x subnet (except the host that sent the broadcast packet to the Layer 3 Switch).
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 Layer 3 Switch to treat IP packets with all zeros in the host portion of
the destination IP address as broadcast packets.
NOTE
When you enable the Layer 3 Switch for zero-based subnet broadcasts, the Layer 3 Switch still treats
IP packets with all ones the host portion as IP subnet broadcasts too. Thus, the Layer 3 Switch 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 Layer 3 Switch for zero-based IP subnet broadcasts in addition to ones-based IP
subnet broadcasts, enter the following command.
Brocade(config)# ip broadcast-zero
Brocade(config)# write memory
Brocade(config)# end
Brocade# reload