Introduction To Vlans - ZyXEL Communications XGS1930-28 User Manual

Table 23 Basic Setting > General Setup (continued)
LABEL
New Date (yyyy-
mm-dd)
Time Zone
Daylight Saving
Time
Start Date
End Date
Apply
Cancel

8.4 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 groups;
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.
VLAN also increases network performance by limiting broadcasts to a smaller and more manageable
logical broadcast domain. In traditional switched environments, all broadcast packets go to each and
every individual port. With VLAN, all broadcasts are confined to a specific broadcast domain.
Chapter 8 Basic Setting
DESCRIPTION
Enter the new date in year, month and day format. The new date then appears in the Current
Date field after you click Apply.
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.
Daylight saving is a period from late spring to early fall when many countries set their clocks
ahead of normal local time by one hour to give more daytime light in the evening.
Select this option if you use Daylight Saving Time.
Configure the day and time when Daylight Saving Time starts if you selected Daylight Saving
Time. The time is displayed in the 24 hour format. Here are a couple of examples:
Daylight Saving Time starts in most parts of the United States on the second Sunday of March.
Each time zone in the United States starts using Daylight Saving Time at 2 A.M. local time. So in
the United States you would select Second, Sunday, March and 2:00.
Daylight Saving Time starts in the European Union on the last Sunday of March. All of the time
zones in the European Union start using Daylight Saving Time at the same moment (1 A.M. GMT
or UTC). So in the European Union you would select Last, Sunday, March and the last field
depends on your time zone. In Germany for instance, you would select 2:00 because
Germany's time zone is one hour ahead of GMT or UTC (GMT+1).
Configure the day and time when Daylight Saving Time ends if you selected Daylight Saving
Time. The time field uses the 24 hour format. Here are a couple of examples:
Daylight Saving Time ends in the United States on the first Sunday of November. Each time
zone in the United States stops using Daylight Saving Time at 2 A.M. local time. So in the United
States you would select First, Sunday, November and 2:00.
Daylight Saving Time ends in the European Union on the last Sunday of October. All of the time
zones in the European Union stop using Daylight Saving Time at the same moment (1 A.M. GMT
or UTC). So in the European Union you would select Last, Sunday, October and the last field
depends on your time zone. In Germany for instance, you would select 2:00 because
Germany's time zone is one hour ahead of GMT or UTC (GMT+1).
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.
Click Cancel to begin configuring this screen afresh.
XGS1930 Series User's Guide
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