5
Configuring Routing
Configuring ARP
Configuring Global IP Settings
Router
Configuring Routing Information Protocol (RIP)
200 Series software supports IP routing. Use the links in the
Routing
navigation menu to manage
routing on the system.
When a packet enters the switch, the destination MAC address is checked to see if it matches any of the
configured routing interfaces. If it does, then the silicon searches the host table for a matching
destination IP address. If an entry is found, then the packet is routed to the host. If there is not a
matching entry, then the switch performs a longest prefix match on the destination IP address. If an
entry is found, then the packet is routed to the next hop. If there is no match, then the packet is routed
to the next hop specified in the default route. If there is no default route configured, then the packet is
passed to the 6200 series software to be handled appropriately.
The routing table can have entries added either statically by the administrator or dynamically via a
routing protocol. The host table can have entries added either statically by the administrator or
dynamically via ARP.
. BGP is available as a separate
module and might not be available on all platforms. The BGP features can be configured only
by using the CLI. No web-based administrative pages are available for BGP configuration.
Configuring ARP
The
ARP (Address Resolution Protocol)
protocol associates a Layer 2 MAC address with a Layer 3 IPv4
address. 200 Series 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), every recipient has the opportunity to store the sender’s IP and MAC address in
their respective ARP cache. The ARP response, being unicast, is normally seen only by the requestor,
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