Cisco Sg3008 Manual

							Port Management
Setting Port Configuration
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-Combo Fiber—SFP Fiber Gigabit Interface Conver ter Por t with the 
following values: 100M and 1000M (type: ComboF).
-10G-Fiber Optics—Ports with speed of either 1G or 10G.
NOTESFP Fiber takes precedence in Combo ports when both ports are 
being used.
•Administrative Status—Select whether the port must be Up or Down when 
the device is rebooted.
•Operational Status—Displays whether the port is currently Up or Down. If 
the port is down because of an error, the description of the error is displayed.
•Link Status SNMP Traps—Select to enable generation of SNMP traps that 
notify of changes to the link status of the port.
•Time Range—Select to enable the time range during which the port is in Up 
state. When the time range is not active, the port is in shutdown. If a time 
range is configured, it is effective only when the port is administratively Up. 
If a time range is not yet defined, click Edit to go to the Time Range page.
•Time Range Name—Select the profile that specifies the time range.
•Operational Time-Range State—Displays whether the time range is 
currently active or inactive.
•Reactivate Suspended Port—Select to reactivate a port that has been 
suspended. There are numerous ways that a port can be suspended, such 
as through the locked port security option, dot1x single host violation, 
loopback detection, STP loopback guard or Access Control List (ACL) 
configurations. The reactivate operation brings the port up without regard to 
why the port was suspended.
•Auto-Negotiation—Select to enable auto-negotiation on the port. Auto-
negotiation enables a port to advertise its transmission speed, duplex mode, 
and Flow Control abilities to the port link partner.
•Operational Auto-Negotiation—Displays the current auto-negotiation 
status on the port.
•Administrative Port Speed—Configure the speed of the port. The port 
type determines which the available speeds. You can designate 
Administrative Speed only when port auto-negotiation
 is disabled. 
•Operational Port Speed—Displays the current port speed that is the result 
of negotiation. 
						

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Setting Port Configuration
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•Administrative Duplex Mode—Select the port duplex mode. This field is 
configurable only when auto-negotiation is disabled, and the port speed is 
s et  to 10M or 100M . At p or t sp e e d of 1G,  t he m o de is al ways full  d uplex .  The 
possible options are:
-Fu ll—The interface supports transmission between the device and the 
client in both directions simultaneously.
-Half—The interface supports transmission between the device and the 
client in only one direction at a time.
•Operational Duplex Mode—Displays the ports current duplex mode.
•Auto Advertisement—Select the capabilities advertised by auto-
negotiation when it is enabled. The options are:
-Max Capability—All port speeds and duplex mode settings can be 
accepted. 
-10 Half—10 Mbps speed and Half Duplex mode.
-10 Full—10 Mbps speed and Full Duplex mode.
-100 Half—100 Mbps speed and Half Duplex mode.
-100 Full—100 Mbps speed and Full Duplex mode.
-1000 Full—1000 Mbps speed and Full Duplex mode.
•Operational Advertisement—Displays the capabilities currently published 
to the ports neighbor. The possible options are those specified in the 
Administrative Adver tisement field.
•Neighbor Advertisement—Displays the capabilities advertised by the 
neighboring device (link partner).
•Back Pressure—Select the Back Pressure mode on the port (used with Half 
Duplex mode) to slow down the packet reception speed when the device is 
congested. It disables the remote port, preventing it from sending packets 
by jamming the signal.
•Flow Control—Enable or disable 802.3x Flow Control, or enable the auto-
negotiation of Flow Control on the port (only when in Full Duplex mode).
•MDI/MDIX—the Media Dependent Inter face (MDI)/Media Dependent 
Inter face with Cros sover (MDIX) status on the port. 
The options are:
-MDIX—Select to swap the ports transmit and receives pairs. 
						

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Setting Port Configuration
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-MDI—Select to connect this device to a station by using a straight 
through cable. 
-Auto—Select to configure this device to automatically detect the correct 
pinouts for the connection to another device. 
•Operational MDI/MDIX—Displays the current MDI/MDIX setting.
•Protected Port—Select to make this a protected port. (A protected port is 
also referred as a Private VLAN Edge (PVE).) The features of a protected port 
are as follows:
-Protected Ports provide Layer 2 isolation between interfaces (Ethernet 
ports and LAGs) that share the same VLAN. 
-Packets received from protected ports can be forwarded only to 
unprotected egress ports. Protected port filtering rules are also applied 
to packets that are forwarded by software, such as snooping 
applications.
-Port protection is not subject to VLAN membership. Devices connected 
to protected ports are not allowed to communicate with each other, even 
if they are members of the same VLAN. 
-Both ports and LAGs can be defined as protected or unprotected. 
Protected LAGs are described in the Configuring LAG Settings section.
•Member in LAG—If the port is a member of a LAG, the LAG number 
appears; otherwise this field is left blank.
STEP  6Click Apply. The Port Settings are written to the Running Configuration file.
Error Recovery Settings
This page enables automatically reactivating a port that has been shutdown 
because of an error condition. 
To configure error recovery settings:
STEP 1Click Port Management > Error Recovery Settings.
STEP  2Enter the following fields:
•Automatic Recovery Interval—Select to enable the error recovery 
mechanism for the port security err-disable state. 
						

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Link Aggregation
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•Port Security—Select to enable the error recovery mechanism for the port 
security err-disable state.
•802.1x Single Host Violation—Select to enable error recovery mechanism 
for the 802.1x error-disable state.
•ACL Deny—Select to enable. error recovery mechanism for the ACL deny 
error-disable state.
•STP BPDU Guard—Select to enable the error recovery mechanism for thee 
STP BPDU guard error-disable state.
•UDLD—S ele ct to enabl e er ror  re c over y me chani sm for t he UDL D shutdown 
state.
STEP  3Click Apply to update the global setting. 
To manually reactivate a port:
STEP 1Click Port Management > Error Recovery Settings.
The list of inactivated interfaces along with their Suspension Reason is displayed.
STEP  2Select the interface to be reactivated.
STEP  3Click Reactivate.
Link Aggregation
This section describes how to configure LAGs. It covers the following topics:
•Link Aggregation Overview
•Static and Dynamic LAG Workflow
•Defining LAG Management
•Configuring LAG Settings
•Configuring LACP 
						

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Link Aggregation
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Link Aggregation Overview
Link Aggregation Control Protocol (LACP) is part of the IEEE specification (802.3az) 
that enables you to bundle several physical ports together to form a single logical 
channel (LAG). LAGs multiply the bandwidth, increase port flexibility, and provide 
link redundancy between two devices.
Two types of LAGs are supported:
•Static—A LAG is static if the LACP is disabled on it.   The group of ports 
assigned to a static LAG are always active members. After a LAG is manually 
created, the LACP option cannot be added or removed, until the LAG is 
edited and a member is removed (which can be added prior to applying), 
then the LACP button become available for editing.
•Dynamic—A LAG is dynamic if LACP is enabled on it. The group of ports 
assigned to dynamic LAG are candidate ports. LACP determines which 
candidate ports are active member ports. The non-active candidate ports 
are standby ports ready to replace any failing active member ports.
Load Balancing
Traffic forwarded to a LAG is load-balanced across the active member ports, thus 
achieving an effective bandwidth close to the aggregate bandwidth of all the 
active member ports of the LAG.
Traffic load balancing over the active member ports of a LAG is managed by a 
hash-based distribution function that distributes Unicast and Multicast traffic 
based on Layer 2 or Layer 3 packet header information. 
The device supports two modes of load balancing:
•By MAC Addresses—Based on the destination and source MAC addresses 
of all packets.
•By IP and MAC Addresses—Based on the destination and source IP 
addresses for IP packets, and destination and source MAC addresses for 
non-IP packets.
LAG Management
In general, a LAG is treated by the system as a single logical port. In particular, the 
LAG has port attributes similar to a regular port, such as state and speed.
The device supports 32 LAGs with up to 8 ports in a LAG group.  
						

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Every LAG has the following characteristics:
•All ports in a LAG must be of the same media type.
•To add a port to the LAG, it cannot belong to any VLAN except the default 
VLAN.
•Ports in a LAG must not be assigned to another LAG.
•No more than eight ports are assigned to a static LAG and no more than 16 
ports can be candidates for a dynamic LAG.
•All the ports in a LAG must have auto-negotiation disabled, although the 
LAG can have auto-negotiation enabled.
•When a port is added to a LAG, the configuration of the LAG is applied to 
the port. When the port is removed from the LAG, its original configuration 
is reapplied.
•Protocols, such as Spanning Tree, consider all the ports in the LAG to be 
one port.
Default Settings and Configuration
Ports are not members of a LAG and are not candidates to become part of a LAG.
Static and Dynamic LAG Workflow
After a LAG has been manually created, LACP cannot be added or removed until 
the LAG is edited and a member is removed. Only then the LACP button become 
available for editing.
To configure a static LAG, perform the following actions: 
1. Disable LACP on the LAG to make it static.   Assign up to eight member ports to 
the static LAG by selecting and moving the ports from the Port List to the LAG 
Members list. Select the load balancing algorithm for the LAG. Perform these 
actions in the LAG Management page.
2. Configure various aspects of the LAG, such as speed and flow control by using 
the LAG Settings page. 
						

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Link Aggregation
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To configure a dynamic LAG, perform the following actions:
1. E n a b l e  L A C P  o n  t h e  L A G .    A s s i g n  u p  to  1 6  c a n d i d a te s  p o r t s  to  t h e  d y n a m i c  L A G  
by selecting and moving the ports from the Port List to the LAG Members List 
by using the LAG Management page.
2. Configure various aspects of the LAG, such as speed and flow control by using 
the LAG Settings page.
3. Set the LACP priority and timeout of the ports in the LAG by using the LACP 
page.
Defining LAG Management
The LAG Management page displays the global and per LAG settings. The page 
also enables you to configure the global setting and to select and edit the desired 
LAG on the Edit LAG Membership page. 
To select the load balancing algorithm of the LAG:
STEP 1Click Port Management > Link Aggregation > LAG Management.
STEP  2Select one of the following Load Balance Algorithms:
•MAC Address—Perform load balancing by source and destination MAC 
addresses on all packets.
•IP/MAC Address—Perform load balancing by the source and destination IP 
addresses on IP packets, and by the source and destination MAC addresses 
on non-IP packets 
STEP  3Click Apply. The Load Balance Algorithm is saved to the Running Configuration file.
To define the member or candidate ports in a LAG. 
STEP 1Select the LAG to be configured, and click Edit.
STEP  2Enter the values for the following fields:
•LAG—Select the LAG number.
•LAG Name—Enter the LAG name or a comment.
•LACP—Select to enable LACP on the selected LAG. This makes it a dynamic 
LAG. This field can only be enabled after moving a port to the LAG in the next 
field. 
						

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•Port List—Move those ports that are to be assigned to the LAG from the 
Port List to the LAG Members list. Up to eight ports per static LAG can be 
assigned, and 16 ports can be assigned to a dynamic LAG.
STEP  3Click Apply. LAG membership is saved to the Running Configuration file.
Configuring LAG Settings
The LAG Settings page displays a table of current settings for all LAGs. You can 
configure the settings of selected LAGs, and reactivate suspended LAGs by 
launching the Edit LAG Settings page. 
To configure the LAG settings or reactivate a suspended LAG:
STEP 1Click Port Management > Link Aggregation > LAG Settings.
STEP  2Select a LAG, and click Edit.
STEP  3Enter the values for the following fields:
•LAG—Select the LAG ID number.
•Description—Enter the LAG name or a comment.
•LAG Type—Displays the port type that comprises the LAG. 
•Administrative Status—Set the selected LAG to be Up or Down. 
•Operational Status—Displays whether the LAG is currently operating.
•Link Status SNMP Traps—Select to enable generation of SNMP traps 
notifying of changes to the link status of the ports in the LAG.
•Time Range—Select to enable the time range during which the port is in Up 
state. When the time range is not active, the port is in shutdown. If a time 
range is configured, it is effective only when the port is administratively Up. 
If a time range is not yet defined, click Edit to go to the Time Range page.
•Time Range Name—Select the profile that specifies the time range.
•Operational Time-Range State—Displays whether the time range is 
currently active or inactive.
•Reactivate Suspended LAG—Select to reactivate a port if the LAG has 
been disabled through the locked port security option or through ACL 
configurations. 
						

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Link Aggregation
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•Administrative Auto Negotiation—Enables or disable auto-negotiation on 
the LAG. Auto-negotiation is a protocol between two link partners that 
enables a LAG to advertise its transmission speed and flow control to its 
partner (the Flow Control default is disabled). It is recommended to keep 
auto-negotiation enabled on both sides of an aggregate link, or disabled on 
both sides, while ensuring that link speeds are identical.
•Operational Auto Negotiation—Displays the auto-negotiation setting.
•Administrative Speed—Select the LAG speed. 
•Operational LAG Speed—Displays the current speed at which the LAG is 
operating.
•Administrative Advertisement—Select the capabilities to be advertised by 
the LAG. The options are:
-Max Capabilit y—All LAG speeds and both duplex modes are available. 
-10 Full—The LAG advertises a 10 Mbps speed and the mode is full 
duplex.
-100 Full—The LAG advertises a 100 Mbps speed and the mode is full 
duplex.
-1000 Full—The LAG advertises a 1000 Mbps speed and the mode is full 
duplex.
•Operational Advertisement—Displays the Administrative Advertisement 
status. The LAG advertises its capabilities to its neighbor LAG to start the 
negotiation process. The possible values are those specified in the 
Administrative Adver tisement field.
•Administrative Flow Control—Set Flow Control to either Enable or Disable 
or enable the Auto-Negotiation of Flow Control on the LAG.
•Operational Flow Control—Displays the current Flow Control setting. 
•Protected LAG—Select to make the LAG a protected port for Layer 2 
isolation. See the Port Configuration description in Setting Basic Port 
Configuration for details regarding protected ports and LAGs. 
STEP  4Click Apply. The Running Configuration file is updated. 
						

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Link Aggregation
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Configuring LACP
A dynamic LAG is LACP-enabled, and LACP is run on every candidate port 
defined in the LAG.
LACP Priority and Rules
LACP system priority and LACP port priority are both used to determine which of 
the candidate ports become active member ports in a dynamic LAG configured 
with more than eight candidate ports. 
The selected candidate ports of the LAG are all connected to the same remote 
device. Both the local and remote switches have a LACP system priority. 
The following algorithm is used to determine whether LACP port priorities are 
taken from the local or remote device: the local LACP System Priority is compared 
to the remote LACP System Priority. The device with the lowest priority controls 
candidate port selection to the LAG. If both priorities are the same, the local and 
remote MAC addresses are compared. The priority of the device with the lowest 
MAC address controls candidate port selection to the LAG. 
A dynamic LAG can have up to 16 Ethernet ports of the same type. Up to eight 
ports can be active, and up to eight ports can be in standby mode. When there are 
more than eight ports in the dynamic LAG, the device on the controlling end of the 
link uses port priorities to determine which ports are bundled into the LAG and 
which ports are put in hot-standby mode. Port priorities on the other device (the 
non-controlling end of the link) are ignored. 
The following are additional rules used to select the active or standby ports in a 
dynamic LACP:
•Any link operating at a different speed from the highest-speed active 
member or operating at half-duplex is made standby. All the active ports in 
a dynamic LAG operate at the same baud rate.
•If the port LACP priority of the link is lower than that of the currently-active 
link members, and the number of active members is already at the maximum 
number, the link is made inactive, and placed in standby mode.
LACP With No Link Partner
In order for LACP to create a LAG, the ports on both link ends should be 
configured for LACP, meaning that the ports send LACP PDUs and handle received 
PDUs.