Brocade BigIron RX Series Configuration Guide - Manual (Page 273)

BigIron RX Series Configuration Guide 195
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Configuring ARP parameters
7
When a floating static ARP entry (Static ARP entry without the outgoing interface defined) is added
to the ARP Inspection table, the mapping is checked against the current static ARP table. If an ARP
entry with a matching IP but mismatch MAC is found, it will be deleted and a re-arp on the IP will be
issued.
When an ARP entry is deleted from ARP Inspection table, the corresponding entry in the static ARP
table will also be deleted.
To create a floating static ARP entry for a static MAC entry, enter a command such as the following.
BigIron RX(config)# arp 192.53.4.2 1245.7654.2348
The command adds a floating static ARP entry that maps IP address 192.53.4.2 to MAC address
1245.7654.2348.
Syntax: arp <ip-add> <mac-addr>
The <ip-addr> parameter specifies the IP address of the device that has the MAC address of the
entry.
The <mac-addr> parameter specifies the MAC address of the entry.
Static route ARP validation check
You can configure the BigIron RX to perform validation checks on the destination MAC address, the
sender and target IP addresses, and the source MAC address.
You can enable ARP validation check on the global basis. When feature is enabled, the static route
will only be installed when the next hop ARP has been resolved.
Configuring an ARP validation check
To enable the ARP validation check globally, enter a command such as the following.
BigIron RX(config)#ip route validate-nexthop-arp
Syntax: [no] ip route validate-nexthop-arp
Use the no form of the command to disable the ARP validation feature. When ARP validation is
disabled, the static route will be installed without checking the validity of the next hop.
Enabling the next hop validate ARP timer
The next hop validate ARP timer works only on the ARP entries created when the ARP validation
check feature has been enabled. The timer is used to age out the ARP entries when the next hop
goes down. All other ARP entries in the system, which are NOT created due to static routes, follow
the normal ARP age timer with default value of 3 minutes.
Use the ARP validation timer to reduce the response time where the static route with the next hop
down can be replaced quickly with a route with active next hop.
To set the ARP validation timer to 30 seconds, enter commnads such as the following.
BigIron RX(config)#ip route validate-nexthop-arp
BigIron RX(config)#ip route validate-nexthop-arp timer 30
Syntax: [no] ip route validate-nexthop-arp timer <value>
The default is 200 seconds.