I-4
Compaq ServerNet II PCI Adapter and Switch Installation Guide
of IP addresses sequentially until an agent extension responds. The management application
continues to issue requests to this address until it fails. When the management application
detects that an agent extension has failed, it can go down the list of known IP addresses issuing
requests until it finds another agent extension that responds to the query. When it finds an agent
extension that responds it will continue using this IP address until another failure occurs
A request by an SNMP management application for ServerNet II Switch data is processed only
by the node that is running the primary SANMan. The request is processed according to the
following general sequence of operations:
■
An SNMP management application issues a Get request for ServerNet II Switch data
using the TCP/IP address or domain name service (DNS) of the node.
■
The Get request is forwarded over the LAN or ServerNet II SAN to the Microsoft
Windows 2000 Extendible Agent on that node.
■
The Microsoft Windows 2000 Extendible Agent sends a SnmpExtensionQuery (Get)
request to the ServerNet II Switch agent extension on that node.
■
The ServerNet II Switch agent extension calls the appropriate Get function from the
ServerNet II Device Access Layer (DAL) DLL. A DAL Get function call results in a
DeviceIoControl () call to the SANMan on that node.
■
The SANMan retrieves the requested ServerNet II Switch data, such as error, status,
routing, and configuration. Topology data is maintained by the SANMan.
■
The data is routed to the requesting SNMP management application.
Monitoring the Switch for Trap Conditions
The agent extension generates SNMP traps that can be forwarded to management applications
whenever certain events occur. SNMP traps are generated by the agent extension when one or
more of the following events are delivered by SANMan to the primary agent extension:
■
Link Alive – Indicates a port status has changed between up and down
■
Neighbor Change – Indicates that an unexpected neighbor was encountered at a
Switch port
■
Link, Packet Level, and IBC events – Unwanted illegal symbols, keep-alive errors, TLB
(this link bad) errors have exceeded a predefined threshold
■
Access Violation – Command received from an unauthorized ServerNet II ID attempted to
perform privileged operation
■
IBC Notification errors – Indicates Switch ownership change
■
Firmware upgrade
■
Configuration update
■
SANMan failover
■
Switch fan failure
The ServerNet II Switch MIB defines 11 possible SNMP traps. If enabled, the traps are
generated whenever the asynchronous event notification is received from the SANMan. The
generic trap of 6 is the enterprise-specific trap. By default, all traps are enabled when the agent
extension is started. See Appendix J for a list of Switch traps.