Extreme Networks ExtremeWare 7.7, Справочник по командам

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ExtremeWare 7.7 Command Reference Guide 1651
use a single UDP-forwarding profile. UDP packets directed toward a VLAN use an all-ones broadcast
on that VLAN.
Proxy Address Resolution Protocol (ARP) was first developed so that ARP-capable devices could
respond to ARP Request packets on behalf of ARP-incapable devices. Proxy ARP can also be used to
achieve router redundancy and simplify IP client configuration. The Extreme Networks switch supports
proxy ARP for this type of network configuration.
Once IP ARP is configured, the system responds to ARP Requests on behalf of the device, as long as the
following conditions are satisfied:
• The valid IP ARP Request is received on a router interface.
• The target IP address matches the IP address configured in the proxy ARP table.
• The proxy ARP table entry indicates that the system should always answer this ARP Request,
regardless of the ingress VLAN (the
always
parameter must be applied).
After all the proxy ARP conditions have been met, the switch formulates an ARP Response using the
configured MAC address in the packet.
In some networks, it is desirable to configure the IP host with a wider subnet than the actual subnet
mask of the segment. Proxy ARP can be used so that the router answers ARP Requests for devices
outside of the subnet. As a result, the host communicates as if all devices are local. In reality,
communication with devices outside of the subnet are proxied by the router.