Cisco Sg3008 Manual

							Administration: Time Settings
Configuring System Time
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•IPv4 Source Interface—Select the IPv4 interface whose IPv4 address will 
be used as the source IPv4 address in messages used for communication 
with the SNTP server. 
•IPv6 Source Interface—Select the IPv6 interface whose IPv6 address will 
be used as the source IPv6 address in messages used for communication 
with the SNTP server.
NOTEIf the Auto option is selected, the system takes the source IP address 
from the IP address defined on the outgoing interface.
This page displays the following information for each Unicast SNTP server:
•SNTP Server—SNTP server IP address. The preferred server, or hostname, 
is chosen according to its stratum level.
•Poll Interval—Displays whether polling is enabled or disabled. 
•Authentication Key ID—Key Identification used to communicate between 
the SNTP server and device.
•Stratum Level—Distance from the reference clock expressed as a 
numerical value. An SNTP server cannot be the primary server (stratum 
level 1) unless polling interval is enabled.
•Status—SNTP server status. The possible values are: 
-Up—SNTP server is currently operating normally.
-Down—SNTP server is currently not available. 
-Unknown—SNTP server is currently being searched for by the device.
-
In Process—Occurs when the SNTP server has not fully trusted its own 
time server (i.e. when first booting up the SNTP server).
•Last Response—Date and time of the last time a response was received 
from this SNTP server.
•Offset—The estimated offset of the servers clock relative to the local clock, 
in milliseconds. The host determines the value of this offset using the 
algorithm described in RFC 2030.
•Delay—The estimated round-trip delay of the servers clock relative to the 
local clock over the network path between them, in milliseconds. The host 
determines the value of this delay using the algorithm described in RFC 
2030. 
						

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•Source—How SNTP server was defined, for example: manually or from 
DHCPv6 server.
•Interface—Interface on which packets are received.
STEP  3To add a Unicast SNTP server, enable SNTP Client Unicast.
STEP  4Click Add.
STEP  5Enter the following parameters:
•Server Definition—Select if the SNTP server is going to be identified by its 
IP address or if you are going to select a well-known SNTP server by name 
from the list.
NOTETo specify a well-known SNTP server, the device must be connected 
to the Internet and configured with a DNS server or configured so that a DNS 
server is identified by using DHCP. (See DNS Settings)
•IP Version—Select the version of the IP address: Version 6 or Version 4.
•IPv6 Address Type—Select the IPv6 address type (if IPv6 is used). The 
options are
-Link Local—The IPv6 address uniquely identifies hosts on a single 
network link. A link local address has a prefix of FE80, is not routable, and 
can be used for communication only on the local network. Only one link 
local address is supported. If a link local address exists on the interface, 
this entry replaces the address in the configuration. 
-Global—The IPv6 address is a global Unicast IPV6 type that is visible and 
reachable from other networks. 
•Link Local Interface—Select the link local interface (if IPv6 Address Type 
Link Local is selected) from the list. 
•SNTP Server IP Address—Enter the SNTP server IP address. The format 
depends on which address type was selected.
•SNTP Server—Select the name of the SNTP server from a list of well-known 
NTP servers. If other is chosen, enter name of SNTP server in the adjacent 
field.
•Poll Interval—Select to enable polling of the SNTP server for system time 
information. All NTP servers that are registered for polling are polled, and the 
clock is selected from the server with the lowest stratum level (distance from 
the reference clock) that is reachable. The server with the lowest stratum is 
considered to be the primary server. The server with the next lowest stratum  
						

							Administration: Time Settings
Configuring System Time
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is a secondary server, and so forth. If the primary server is down, the device 
polls all servers with the polling setting enabled, and selects a new primary 
server with the lowest stratum.
•Authentication—Select the check box to enable authentication.
•Authentication Key ID—If authentication is enabled, select the value of the 
key ID. (Create the authentication keys using the SNTP Authentication page.)
STEP  6Click Apply. The STNP server is added, and you are returned to the main page.
Configuring the SNTP Mode
The device can be in active and/or passive mode (see SNTP Modes for more 
information).
To enable receiving SNTP packets from all servers on the subnet and/or to enable 
transmitting time requests to SNTP servers:
STEP 1Click Administration > Time Settings > SNTP Multicast/Anycast.
STEP  2Select from the following options:
•SNTP IPv4 Multicast Client Mode (Client Broadcast Reception)—Select to 
receive system time IPv4 Multicast transmissions from any SNTP server on 
the subnet. 
•SNTP IPv6 Multicast Client Mode (Client Broadcast Reception)—Select to 
receive system time IPv6 Multicast transmissions from any SNTP server on 
the subnet. 
•SNTP IPv4 Anycast Client Mode (Client Broadcast Transmission)—Select to 
transmit SNTP IPv4 synchronization packets requesting system time 
information. The packets are transmitted to all SNTP servers on the subnet.
•SNTP IPv6 Anycast Client Mode (Client Broadcast Transmission)—Select to 
transmit SNTP IPv6 synchronization packets requesting system time 
information. The packets are transmitted to all SNTP servers on the subnet. 
STEP  3If the system is in Layer 3 system mode, click Add to select the interface for SNTP 
reception/transmission. 
						

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Select an interface and select the reception/transmission options.
STEP  4Click Apply to save the settings to the Running Configuration file.
Defining SNTP Authentication 
SNTP clients can authenticate responses by using HMAC-MD5. An SNTP server is 
associated with a key, which is used as input together with the response itself to 
the MD5 function; the result of the MD5 is also included in the response packet.
The SNTP Authentication page enables configuration of the authentication keys 
that are used when communicating with an SNTP server that requires 
authentication. 
The authentication key is created on the SNTP server in a separate process that 
depends on the type of SNTP server you are using. Consult with the SNTP server 
system administrator for more information.
Workflow
STEP 1Enable authentication in the SNTP Authentication page.
STEP  2Create a key in the SNTP Authentication page.
STEP  3Associate this key with an SNTP server in the SNTP Unicast page.
To enable SNTP authentication and define keys:
STEP 1Click Administration > Time Settings > SNTP Authentication.
STEP  2Select SNTP Authentication to support authentication of an SNTP session 
between the device and an SNTP server. 
STEP  3Click Apply to update the device.
STEP  4Click Add.
STEP  5Enter the following parameters:
•Authentication Key ID—Enter the number used to identify this SNTP 
authentication key internally.  
						

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•Authentication Key—Enter the key used for authentication (up to eight 
characters). The SNTP server must send this key for the device to 
synchronize to it.
•Trusted Key—Select to enable the device to receive synchronization 
information only from a SNTP server by using this authentication key. 
STEP  6Click Apply. The SNTP Authentication parameters are written to the Running 
Configuration file.
Time Range
Time ranges can be defined and associated with the following types of 
commands, so that they are applied only during that time range:
•ACLs
•8021X Port Authentication
•Por t Stat
•Ti m e - B a s e d  P o E
There are two types of time ranges:
•Absolute —This type of time range begins on a specific date or 
immediately and ends on a specific date or extends infinitely. It is created in 
the Time Range pages. A recurring element can be added to it. 
•Recurring — This type of time range contains a time range element that is 
added to an absolute range, and begins and ends on a recurring basis. It is 
defined in the Recurring Range pages.
If a time range includes both absolute and recurring ranges, the process 
associated with it is activated only if both absolute start time and the recurring 
time range have been reached. The process is deactivated when either of the time 
ranges is reached.
The device supports a maximum of 10 absolute time ranges.
All time specifications are interpreted as local time (Daylight Saving Time does not 
affect this).To ensure that the time range entries take effect at the desired times, 
the system time must be set. 
The time-range feature can be used for the following:
•Limit access of computers to the network during business hours (for 
example), after which the network ports are locked, and access to the rest  
						

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Configuring System Time
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of the network is blocked (see Chapter 9, “Configuring Ports” and 
Chapter 9, “Configuring LAG Settings”)
•Limit PoE operation to a specified period.
Absolute Time Range 
To define an absolute time range:
STEP 1Click Administration > Ti m e  S e t t i n g s > Ti m e Range.
The existing time ranges are displayed.
STEP  2To add a new time range, click Add. 
STEP  3Enter the following fields:
•Time Range Name—Enter a new time range name. 
•Absolute Starting Time—To define the start time, enter the following: 
-Immediate—Select for the time range to start immediately.
-Date, Time—Enter the date and time that the Time Range begins.
•Absolute Ending Time—To define the start time, enter the following: 
-Infinite—Select for the time range to never end.
-Date, Time—Enter the date and time that the Time Range ends.
STEP  4To add a recurring time range, click Recurring Range. 
Recurring Time Range
A recurring time element can be added to an absolute time range. This limits the 
operation to certain time periods within the absolute range.
To add a recurring time range element to an absolute time range:
STEP 1Click Administration > Ti m e  S e t t i n g s > Recurring Range.
The existing recurring time ranges are displayed (filtered per a specific, absolute 
time range.)
STEP  2Select the absolute time range to which to add the recurring range. 
						

							Administration: Time Settings
Configuring System Time
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STEP  3To add a new recurring time range, click Add. 
STEP  4Enter the following fields:
•Recurring Starting Time—Enter the date and time that the Time Range 
begins on a recurring basis. 
Recurring Ending Time—Enter the date and time that the Time Range ends on a 
recurring basis. 
						

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Administration: Diagnostics 
This section contains information for configuring port mirroring, running cable 
tests, and viewing device operational information.
It covers the following topics:
•Testing Copper Ports
•Displaying Optical Module Status
•Configuring Port and VLAN Mirroring
•Viewing CPU Utilization and Secure Core Technology
Testing Copper Ports
The Copper Test page displays the results of integrated cable tests performed on 
copper cables by the Virtual Cable Tester (VCT).
VCT performs two types of tests:
•Time Domain Reflectometry (TDR) technology tests the quality and 
characteristics of a copper cable attached to a port. Cables of up to 140 
meters long can be tested. These results are displayed in the Test Results 
block of the Copper Test page.
•DSP-based tests are performed on active GE links to measure cable length. 
These results are displayed in the Advanced Information block of the 
Copper Test page.
Preconditions to Running the Copper Por t Test
Before running the test, do the following:
•(Mandatory) Disable Short Reach mode (see the Port Management > Green 
Ethernet > Properties page) 
						

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•(Optional) Disable EEE (see the Port Management > Green Ethernet > 
Properties page)
Use a CAT5 data cable when testing cables using (VCT).
Accuracy of the test results can have an error range of +/- 10 for Advanced Testing 
and +/- 2 for basic testing.
!
CAUTIONWhen a port is tested, it is set to the Down state and communications are 
interrupted. After the test, the port returns to the Up state. It is not recommended 
that you run the copper port test on a port you are using to run the web-based 
switch configuration utility, because communications with that device are 
disrupted. 
To test copper cables attached to ports:
STEP 1Click Administration > Diagnostics > Copper Test.
STEP  2Select the port on which to run the test.
STEP  3Click Copper Test.
STEP  4When the message appears, click OK to confirm that the link can go down or 
Cancel to abort the test.
The following fields are displayed in the Test Results block:
•Last Update—Time of the last test conducted on the port.
•Test Results—Cable test results. Possible values are: 
-OK—Cable passed the test.
-No Cable—Cable is not connected to the port.
-Open Cable—Cable is connected on only one side.
-Shor t Cable—Short circuit has occurred in the cable.
-Unknown Test Result—Error has occurred.
•Distance to Fault—Distance from the port to the location on the cable where 
the fault was discovered.
•Operational Port Status—Displays whether port is up or down. 
						

							Administration: Diagnostics
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If the por t being tested is a Giga por t , the Advanced Information block contains the 
following information, which is refreshed each time you enter the page:
•Cable Length: Provides an estimate for the length.
•Pair—Cable wire pair being tested.
•Status—Wire pair status. Red indicates fault and Green indicates status OK.
•Channel—Cable channel indicating whether the wires are straight or cross-
over.
•Polarity—Indicates if automatic polarity detection and correction has been 
activated for the wire pair.
•Pair Skew—Difference in delay between wire pairs.
NOTETDR tests cannot be performed when the port speed is 10Mbit/Sec.
Displaying Optical Module Status
The Optical Module Status page displays the operating conditions reported by 
the SFP (Small Form-factor Pluggable) transceiver. Some information might not be 
available for SFPs that do not support the digital diagnostic monitoring standard 
SFF-8472.
MSA-compatible SFPs
The following FE SFP (100Mbps) transceivers are supported:
•MFEBX1: 100BASE-BX-20U SFP transceiver for single-mode fiber, 1310 nm 
wavelength, supports up to 20 km.
•MFEFX1: 100BASE-FX SFP transceiver, for multimode fiber, 1310 nm 
wavelength, supports up to 2 km.
•MFELX1: 100BASE-LX SFP transceiver, for single-mode fiber, 1310 nm 
wavelength, supports up to 10 km.
The following GE SFP (1000Mbps) transceivers are supported: 
•MGBBX1: 1000BASE-BX-20U SFP transceiver, for single-mode fiber, 1310 
nm wavelength, supports up to 40 km.