Route Preferences; Netbios Rebroadcast; Multinetting (Multiple Subnets Per Vlan) - Avaya P334T-ML User Manual

Route Preferences

The routing table may contain routes from different sources. Routes to a certain
destination may be learned independently from RIP and from OSPF, and at the
same time, a static route can also be configured to the same destination. While
metrics are used to choose between routes of the same protocol, protocol
preferences are used to choose between routes of different protocols.
The preferences only apply to routes for the same destination IP address and mask.
They do not override the longest-match choice. For example, a high-preference
static default route will not be preferred over a RIP route to the subnet of the
destination.
P334T-ML protocol preferences are listed below from the most to the least preferred:
1 Local (directly attached net)
2 High-preference static (manually configured routes)
3 OSPF internal routes
4 RIP
5 OSPF external routes
6 Low-preference static (manually configured routes).

NetBios Rebroadcast

The P334T-ML can be configured to relay NetBios UDP broadcast packets. This
feature is used for applications such as WINS that use broadcast but may need to
communicate with stations on other subnets or VLANs.
Configuration is performed on a per-interface basis. When a NetBios broadcast
packet arrives from an interface on which NetBios rebroadcast is enabled, the
packet is distributed to all other interfaces configured to rebroadcast NetBios.
If the NetBios packet is a net-directed broadcast (e.g., 149.49.255.255), the packet is
relayed to all other interfaces on the list, and the IP destination of the packet is
replaced by the appropriate interface broadcast address.
If the NetBios broadcast packet is a limited broadcast (e.g., 255.255.255.255), it is
relayed to all VLANs on which there are netbios-enabled interfaces. In that case, the
destination IP address remains the limited broadcast address.

Multinetting (Multiple Subnets per VLAN)

In Router Mode, most applications such as RIP and OSPF, operate per IP interface.
Other applications such as VRRP and DHCP/BOOTP Relay operate per VLAN.
Configuration of these applications is done in the Interface mode. When there is
only a single interface (subnet) per VLAN then system behavior is intuitive since a
subnet and a VLAN are the same.
If the configuration includes multiple interfaces (subnets) per VLAN things start to
get complicated.
P334T-ML User's Guide
Chapter 1 Overview
13