Amer Networks E5Web GUI - Manual (Page 271)

Figure 4.4. A Proxy ARP Example
Transparent Mode as an Alternative
Transparent Mode is an alternative and preferred way of splitting Ethernet networks. Setup is
simpler than using proxy ARP since only the appropriate switch routes need to be defined. Using
switch routes is fully explained in Section 4.8, “Transparent Mode”.
Proxy ARP depends on static routing where the location of networks on interfaces are known
and usually fixed. Transparent mode is more suited to networks whose interface location can
change.
Proxy ARP and High Availability Clusters
In HA clusters, switch routes cannot be used and transparent mode is therefore not an option.
However, proxy ARP does function with HA and is consequently the only way to implement
transparent mode functionality with a cluster.
Note: Not all interfaces can make use of Proxy ARP
It is only possible to have Proxy ARP functioning for Ethernet and VLAN interfaces. Proxy
ARP is not relevant for other types of cOS Core interfaces since ARP is not involved.
Automatically Added Routes
Proxy ARP cannot be enabled for automatically added routes. For example, the routes that cOS
Core creates at initial startup for physical interfaces are automatically added routes. The reason
why Proxy ARP cannot be enabled for these routes is because automatically created routes have
a special status in the cOS Core configuration and are treated differently.
If Proxy ARP is required on an automatically created route, the route should first be deleted and
then manually recreated as a new route. Proxy ARP can then be enabled on the new route.
Chapter 4: Routing
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