4 introduction to vlans, 75 7.4 introduction to vlans – ZyXEL Communications GS-2724 User Manual

Page 75

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Chapter 7 Basic Setting

GS-2724 User’s Guide

75

7.4 Introduction to VLANs

A VLAN (Virtual Local Area Network) allows a physical network to be partitioned into
multiple logical networks. Devices on a logical network belong to one group. A device can
belong to more than one group. With VLAN, a device cannot directly talk to or hear from
devices that are not in the same group(s); the traffic must first go through a router.
In MTU (Multi-Tenant Unit) applications, VLAN is vital in providing isolation and security
among the subscribers. When properly configured, VLAN prevents one subscriber from
accessing the network resources of another on the same LAN, thus a user will not see the
printers and hard disks of another user in the same building.

Use Time Server

when Bootup

Enter the time service protocol that your timeserver uses. Not all time servers

support all protocols, so you may have to use trial and error to find a protocol that

works. The main differences between them are the time format.
When you select the Daytime (RFC 867) format, the Switch displays the day,

month, year and time with no time zone adjustment. When you use this format, it is

recommended that you use a Daytime timeserver within your geographical time

zone.
Time (RFC-868) format displays a 4-byte integer giving the total number of

seconds since 1970/1/1 at 0:0:0.
NTP (RFC-1305) is similar to Time (RFC-868).
The Switch requests time and date settings from the time server in the following

circumstances:

When the Switch starts up.

In 24-hour intervals after starting up.

When you click Apply in this screen.

None is the default value. Enter the time manually. When you enter the time

settings manually, the Switch uses the new settings when you click Apply. Each

time you turn on the Switch, the time and date will be reset to the default values.

Time Server IP

Address

Enter the IP address of your timeserver. The Switch searches for the timeserver for

up to 60 seconds. If you select a timeserver that is unreachable, then this screen

will appear locked for 60 seconds. Please wait.

Current Time

This field displays the time you open this menu (or refresh the menu).

New Time

(hh:min:ss)

Enter the new time in hour, minute and second format. The new time then appears

in the Current Time field after you click Apply.

Current Date

This field displays the date you open this menu.

New Date (yyyy-

mm-dd)

Enter the new date in year, month and day format. The new date then appears in

the Current Date field after you click Apply.

Time Zone

Select the time difference between UTC (Universal Time Coordinated, formerly

known as GMT, Greenwich Mean Time) and your time zone from the drop-down list

box.

Apply

Click Apply to save your changes to the Switch’s run-time memory. The Switch

loses these changes if it is turned off or loses power, so use the Save link on the

top navigation panel to save your changes to the non-volatile memory when you

are done configuring.

Cancel Click

Cancel to reset the fields.

Table 9 General Setup (continued)

LABEL

DESCRIPTION

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