Proxy Arp Between Subnets; Relative Route Priorities - Extreme Networks ExtremeWare XOS Guide Manual

Proxy ARP Between Subnets

In some networks, it is desirable to configure the IP host with a wider subnet than the actual subnet
mask of the segment. You can use proxy ARP 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.
For example, an IP host is configured with a class B address of 100.101.102.103 and a mask of
255.255.0.0. The switch is configured with the IP address 100.101.102.1 and a mask of 255.255.255.0. The
switch is also configured with a proxy ARP entry of IP address 100.101.0.0 and mask 255.255.0.0, without
the parameter.
always
When the IP host tries to communicate with the host at address 100.101.45.67, the IP hosts
communicates as if the two hosts are on the same subnet, and sends out an IP ARP request. The switch
answers on behalf of the device at address 100.101.45.67, using its own MAC address. All subsequent
data packets from 100.101.102.103 are sent to the switch, and the switch routes the packets to
100.101.45.67.

Relative Route Priorities

Table 50 lists the relative priorities assigned to routes depending on the learned source of the route.
NOTE
Although these priorities can be changed, do not attempt any manipulation unless you are expertly familiar with the
possible consequences.
Table 50: Relative route priorities
Route Origin Priority
Direct 10
BlackHole 50
Static 1100
ICMP 1200
OSPFIntra 2200
OSPFInter 2300
RIP 2400
OSPFExtern1 3200
OSPFExtern2 3300
BOOTP 5000
To change the relative route priority, use the following command:
configure iproute priority [rip | blackhole | bootp | ebgp | ibgp | icmp | static |
ospf-intra | ospf-inter | ospf-as-external | ospf-extern1 | ospf-extern2] <priority>
ExtremeWare XOS 11.1 Concepts Guide
Relative Route Priorities
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