User guide

September 2009
OmniSwitch 6400/6850/6855/9000/9000E------ Release 6.4.2.R01 Page 31 of 79
Ethernet Ring Protection (ERP) – G.8032
Ethernet Ring Protection (ERP) switching is a self-configuring algorithm that maintains a loop-free
topology while providing data path redundancy and network scalability. ERP provides fast recovery
times for Ethernet ring topologies by utilizing traditional Ethernet MAC and bridge functions.
This implementation of ERP is based on ITU-T G.8032 and uses the ring Automatic Protection
Switching (APS) protocol to coordinate the prevention of network loops within a bridged Ethernet ring.
Loop prevention is achieved by allowing the traffic to flow on all but one of the links within the
protected Ethernet ring. This link is blocked and is referred to as the Ring Protection Link (RPL).
When a ring failure condition occurs, the RPL is unblocked to allow the flow of traffic to continue
through the ring.
Generic UDP Relay
In addition to BOOTP/DHCP relay, generic UDP relay is available. Using generic UDP relay, traffic
destined for well-known service ports (e.g., NBNS/NBDD, DNS, TFTP, and TACACS) or destined for
a user-defined service port can be forwarded to a maximum of 256 VLANs on the switch. Up to 32
UDP instances can be configured.
Generic Routing Encapsulation
Generic Routing Encapsulation (GRE) is a tunneling protocol that can encapsulate a wide variety of
protocol packet types inside IP tunnels. GRE is used to create a virtual point-to-point link between
routers at remote points in a network. This feature supports the creation, administration, and deletion of
IP interfaces whose underlying virtual device is a GRE tunnel.
GVRP
The GARP VLAN Registration Protocol (GVRP), a protocol compliant with 802.1Q, dynamically
learns and further propagates VLAN membership information across a bridged network. GVRP
dynamically maintains and updates the registration and de-registration of VLANs and prunes
unnecessary broadcast and unicast traffic. Through propagation of GVRP information, a device is
continuously able to update its knowledge of the set of VLANs that currently have active members and
of the ports through which those members can be reached. With GVRP, a single switch is manually
configured with all the desired VLANs for the network, and all other switches on the network
dynamically learn those VLANs. An end station can be plugged into any switch and can be connected
to its desired VLAN. However, for end stations to make use of GVRP, they need Network Interface
Cards (NIC) aware of GVRP.
Health Statistics
To monitor resource availability, the NMS (Network Management System) needs to collect significant
amounts of data from each switch. As the number of ports per switch (and the number of switches)
increases, the volume of data can become overwhelming. The Health Monitoring feature can identify
and monitor a switch’s resource utilization levels and thresholds, improving the efficiency in data
collection.
Health Monitoring provides the following data to the NMS:
• Switch-level input/output, memory and CPU utilization levels
• Module-level and port-level input/output utilization levels
• For each monitored resource, the following variables are defined:
• Most recent utilization level (percentage)