User Manual

M4300 Intelligent Edge Series Fully Managed Stackable Switches
Manage Routing User Manual336
This field displays the IDs of all the VLANs configured on this switch.
6. Use IP Address to enter the IP address to be configured for the VLAN routing interface.
7. Use Subnet Mask to enter the subnet mask to be configured for the VLAN routing interface.
8. Click the Add button.
The VLAN routing interface is added for the selected VLAN ID.
The following table describes the nonconfigurable information displayed on the page.
Configure Address Resolution Protocol
The Address Resolution Protocol (ARP) associates a Layer 2 MAC address with a Layer 3
IPv4 address. The switch software features both dynamic and manual ARP configuration.
With manual ARP configuration, you can statically add entries into the ARP table.
ARP is a necessary part of the Internet Protocol (IP) and is used to translate an IP address to
a media (MAC) address, defined by a local area network (LAN) such as Ethernet.
A station
needing to send an IP packet must learn the MAC address of the IP destination, or of the next
hop router, if the destination is not on the same subnet. This is achieved by broadcasting an
ARP request packet, to which the intended recipient responds by unicasting an ARP reply
containing its MAC address. Once learned, the MAC address is used in the destination
address field of the Layer 2 header prepended to the IP packet.
The ARP cache is a table maintained locally in each station on a network. ARP cache entries
are learned by examining the source information in the
ARP packet payload fields, regardless
of whether it is an ARP request or response. Thus, when an ARP request is broadcast to all
stations on a LAN segment or virtual LAN (VLAN), each recipient has the opportunity to store
the sender’s IP and MAC address in its respective ARP cache. The ARP response, being
unicast, is normally seen only by the requestor, who stores the sender information in its ARP
cache. Newer information always replaces existing content in the ARP cache.
The number of supported ARP entries is platform dependent.
Devices can be moved in a network, which means that the IP address that was at one time
associated with a certain MAC address is now found using a dif
ferent MAC, or it disappeared
from the network altogether (for example, it was reconfigured, disconnected, or powered off).
This leads to stale information in the ARP cache unless entries are updated in reaction to
new information seen on the network, periodically refreshed to determine if an address still
exists, or removed from the cache if the entry was identified as a sender of an ARP packet
during the course of an ageout interval, usually specified through configuration.
Table 119. VLAN Routing Configuration
Field Description
Port The interface assigned to the VLAN for routing.
MAC Address The MAC Address assigned to the VLAN routing interface