IBM 8275-416, User Manual, Page: 21 / 156

longer before accessing the network. Even worse, some higher level protocols
running on the network station may time out, generate error messages or not work
at all.
The 802.1D standard specifies that when a link comes up on the network, the
spanning tree state is set to “Listening”. After the forward delay timer expires, the
spanning tree state is set to “Learning”, and after another forward delay timer
interval the state is set to “Forwarding”. The forward delay timer is set for the entire
network by the root bridge. The default value for this timer is 15 seconds.
With the Fast Spanning Tree function, the transition from “Listening” to “Learning”
and the transition from “Learning” to “Forwarding” takes approximately 6 to 8
seconds. The forward delay timer behavior reverts to the 802.1D standard (15
seconds) after a port goes into forwarding state or blocking state.
Fast Spanning Tree mode is configurable by port. The default is the standard
802.1D protocol. When a port is configured in Fast Spanning Tree mode, it takes
approximately 6 to 8 seconds before traffic can be forwarded on the link. Spanning
tree can also be disabled on the port. For details about configuring ports for Fast
Spanning Tree mode, see the Port Configuration Menu in Chapter 4.
Management and user interfaces
Note: The switch is manageable using the Ethernet network only through the ports
which are members of the Default VLAN (VLAN 1).
You have a choice of these easy-to-use management methods:
v
A VT100 terminal interface allows you to fully manage the switch using a
standard terminal or terminal emulator connected over the network using Telnet
or connected to the switch’s serial port (EIA 232).
“Chapter 2. Accessing the switch” on page 19 describes how to access the switch
using this interface and “Chapter 4. Using the Terminal Interface” on page 31
instructs you about using this interface.
v
A Web-based interface enables you to manage the switch through standard Web
browsers. There must be a physical path between the Web browser and the
switch over the Ethernet network to use this method of connectivity.
“Chapter 2. Accessing the switch” on page 19 describes how to access the switch
using this interface and “Chapter 5. Using the Web Interface” on page 81
instructs you about using this interface.
v
The switch has a Simple Network Management Protocol (SNMP) agent that the
network administrator can access with a standard network manager. The
following MIBs (Management Information Base) are supported:
– MIB II (RFC 1213)
– 8275-416 Enterprise MIB
– RMON MIB (RFC 1757)
– Bridge MIB (RFC 1493)
– IEEE 802.3 Ethernet (RFC 1643)
v
The switch interoperates with the following SNMP Managers:
– Any standard MIB browser (SNMPv1)
– IBM Nways
®
Manager for Windows NT
®
(V2.0 or later)
– IBM Nways Manager for HP-UX (V2.0 or later)
– IBM Nways Manager for AIX
®
(V2.0 or later)
Chapter 1. Introduction
5