Users Guide

Monitoring Network Availability | Performance Monitoring
OMNM 6.5.3 User Guide 419
INTERFACE AGGREGATION
—If a port or interface has sub-interfaces, the total bandwidth of
the parent is the sum of the bandwidth of its children. For example: If GigabitEthernet0/1 has
four subinterfaces GigabitEthernet0/1.1, GigabitEthernet0/1.5, GigabitEthernet0/1.8 and
GigabitEthernet0/1.9 and each sub-interface has bandwidth of 1G, the total bandwidth of
GigabitEthernet0/1 will be 4G.
Unlike trunk aggregation, this does not reverse ingress and egress. The total ingress of the
children becomes the total ingress of the parent, and the total egress of the children becomes
the total egress of the parent. If a port or interface in this configuration loses all of its children
(i.e. the interfaces all get deleted), it reverts to UNCONFIGURED.
ASSOCIATION —If a port is currently UNCONFIGURED and has a physical link to another port
that isn't UNCONFIGURED, it takes the bandwidth of the linked port. This reverses Ingress
and Egress—the linked port's ingress becomes the other port's egress and vice-versa. If
someone deletes the link, the port reverts to UNCONFIGURED.
UNCONFIGURED —The default setting for bandwidth. This sets the ingress and egress
bandwidth of a port or interface to the IfSpeed of the port. This means a 10G port with an
IfSpeed of 10G registers an Ingress and Egress Bandwidth setting of 10G.
Triggering Bandwidth Calculations
On resync, OpenManage Network Manager’s rules check for configured QoS policies and update
the port and interface bandwidth as needed (the CONFIGURED bandwidth calculation type).
OpenManage Network Manager adds any ports and interfaces registering a change in their
bandwidth values (or any newly-created ports and interfaces, as in initial discovery) to a list to be
processed after the resync is over. OpenManage Network Manager also queues the device for
recalculation of TRUNK AGGREGATION every time it collects VLAN data (for example, during
resync or during network data collection).
After the resync finishes, the OpenManage Network Manager bandwidth processor processes the
list of ports and interfaces whose bandwidth values changed and re-check its calculations to see if
INTERFACE AGGREGATION or ASSOCIATION calculation types are applicable, and then
calculate them if necessary.
Link creation, modification or deletion also trigger recalculations of ASSOCIATION calculation
type for the endpoints of the link in question.
OpenManage Network Manager adds any ports/interfaces that change in the bandwidth processor
back to the processor, so that changes can propagate throughout the network. For example, if
OpenManage Network Manager discovers a link and it changes the linked port's bandwidth (type
ASSOCIATED), it needs to recalculate the TRUNK AGGREGATION for all trunk ports on that
device in case the port was an access port and the trunk port bandwidth values need to be updated.
Another example: If an interface's bandwidth value changed, then OpenManage Network Manager
adds its parent for INTERFACE AGGREGATION reprocessing in case it has a parent using that
calculation type that now needs to be updated.
OpenManage Network Manager uses a strict priority to determine which calculation method to use
if multiple are applicable: CONFIGURED > TRUNK AGGREGATION > INTERFACE
AGGREGATION > ASSOCIATED > UNCONFIGURED. This means that if a port has a direct
QoS configuration against it, it doesn't matter if it also has child interfaces or links. OpenManage
Network Manager uses the QoS configuration's value. Likewise, if OpenManage Network Manager
calculates a port’s bandwidth using INTERFACE AGGREGATION and it has a link, the link does
not matter for the purpose of bandwidth calculation since ASSOCIATED is lower priority.