Arp cache and static arp table, Ip route table – Brocade Virtual ADX Switch and Router Guide (Supporting ADX v03.1.00) User Manual
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Brocade Virtual ADX Switch and Router Guide
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Overview
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IP route table
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IP forwarding cache
The software enables you to display these tables. You also can change the capacity of the tables on
an individual basis if needed by changing the memory allocation for the table.
ARP cache and static ARP table
The ARP cache contains entries that map IP addresses to MAC addresses. Generally, the entries
are for devices that are directly attached to the Layer 3 Switch.
An exception is an ARP entry for an interface-based static IP route that goes to a destination that is
one or more router hops away. For this type of entry, the MAC address is either the destination
device’s MAC address or the MAC address of the router interface that answered an ARP request on
behalf of the device, using proxy ARP.
ARP cache
The ARP cache can contain dynamic (learned) entries and static (user-configured) entries. The
software places a dynamic entry in the ARP cache when the Layer 3 Switch learns a device’s MAC
address from an ARP request or ARP reply from the device.
The software can learn an entry when the Layer 3 Switch receives an ARP request from another IP
forwarding device or an ARP reply. Here is an example of a dynamic entry.
Each entry contains the destination device’s IP address and MAC address.
Static ARP table
In addition to the ARP cache, Layer 3 Switches have a static ARP table. Entries in the static ARP
table are user-configured. You can add entries to the static ARP table regardless of whether the
device the entry is for is connected to the Layer 3 Switch.
The software places an entry from the static ARP table into the ARP cache when the entry’s
interface comes up.
Here is an example of a static ARP entry.
Index IP Address MAC Address Port
1
10.95.6.111 0800.093b.d210 1
Each entry lists the information you specified when you created the entry.
To display ARP entries, refer to the following:
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“Displaying the static ARP table”
To configure other ARP parameters, refer to the following:
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IP route table
The IP route table contains paths to IP destinations. The IP route table can receive the paths from
the following sources:
IP Address MAC Address Type Age Port
1
10.95.6.102 0800.5afc.ea21 Dynamic 0 6