Enterasys Networks VH-8TX1UM - Handbuch (Seite 19)

9033718-01 Product Overview 5
fails for any reason, a disabled alternative is activated, thereby
maintaining the connection. This prevents network traffic from circulating
in an endless loop formed by multiple connections to the same LAN
segment.
Spanning Tree parameters are configurable using the Spanning Tree
Configuration Menu of the console menus, the on-board Web agent, or
via SNMP (see Appendix B, “Spanning Tree Concepts,” in the
Management Guide for more information).
Frame Buffering and Frame Latency
The VH-8TX1UM/VH-8TX1MF switch is a store-and-forward switching
device. Each frame is copied into switch memory before being forwarded
to another port. This method ensures that all forwarded frames conform
to a standard Ethernet frame size and have a correct cyclic redundancy
check (CRC) for data integrity. This switching method prevents bad
frames from traversing the network and using up valuable network
bandwidth, as with cut-through switching technology.
To minimize the possibility of dropping frames on congested ports, the
VH-8TX1UM/VH-8TX1MF switch provides 128 KB of frame buffering per
port. This buffer space is used to queue packets for transmission on
congested networks. This is an additional advantage over cut-through
switching technology, which drops packets immediately when
experiencing collisions.
Software Download
The VH-8TX1UM/VH-8TX1MF switch supports the industry-standard
Trivial File Transfer Protocol (TFTP) for downloading software to the
switch. All switch software is stored in a 2 MB sectored flash ROM. The
download feature allows you to easily install software upgrades to the
unit. Software can alternatively be downloaded via the serial console port
using the XMODEM protocol.
A TFTP software download is invoked via the Management Setup Menu
using the console menus. A TFTP download can also be invoked using
the on-board Web agent or via SNMP.
Non-Volatile Parameter Storage
Important operating parameters such as IP addresses, Spanning Tree
configuration, and management security parameters, are stored in non-
volatile flash memory. These values are retained when the switch
experiences power interruptions or is powered down for normal
maintenance.
Configuration and Management Interfaces
The VH-8TX1UM/VH-8TX1MF switch can be managed using any of the
following methods:
• Serial console, out-of-band