Brocade FastIron Ethernet Switch Layer 3 Routing Configuration Guide - Manual (Page 59)

The source MAC address in the Ethernet header and the sender hardware address in the ARP
body must be the same. This validation is performed for the ARP request and response packets.
When the source MAC validation is enabled, the packets with different MAC addresses are
classified as invalid and are dropped.
• ip
Each ARP packet has a sender IP address and target IP address. The target IP address cannot
be invalid or an unexpected IP address in the ARP response packet. The sender IP address
cannot be an invalid or an unexpected IP address in the ARP request and response packets.
Addresses include 0.0.0.0, 255.255.255.255, and all IP multicast addresses. When the IP address
validation is enabled, the packets with invalid and unexpected IP addresses are classified as
invalid and are dropped.
The following example shows validating ARP Packets for the destination MAC
address.
device(config)# configuration terminal
device(config)#ip arp inspection validate dst-mac
Ingress ARP packet priority
You can configure the priority of the ingress ARP packets to an optimum value that depends on your
network configuration and traffic volume. Ingress ARP packets have a default priority value of 4. At the
default priority value, ingress ARP packets may get dropped because of high traffic volume or non-ARP
packets with higher priority values. This can cause devices to become unreachable. If the ingress ARP
packets have higher priority values than the default priority value, a high volume of ARP traffic may lead
to drops in control traffic. This may cause traffic loops in the network.
NOTE
You cannot change the priority of the ingress ARP packets on the management port.
Configuring the priority of ingress ARP packets
To configure the priority of ingress ARP packets, use the arp-internal-priority priority-value
command in global configuration mode.
The following example shows the priority of ingress ARP packets set to level 7.
Brocade(config)# arp-internal-priority 7
Configuring forwarding parameters
The following configurable parameters control the forwarding behavior of BrocadeLayer 3 switches:
• Time-To-Live (TTL) threshold
• Forwarding of directed broadcasts
• Forwarding of source-routed packets
• Ones-based and zero-based broadcasts
All these parameters are global and thus affect all IP interfaces configured on the Layer 3 switch.
Ingress ARP packet priority
FastIron Ethernet Switch Layer 3 Routing Configuration Guide 59
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