- Preface
- Software Licensing
- The Cisco IOS command-line interface (CLI)
- Configuring Interfaces
- Switch Alarms
- Initial Switch Configuration (IP address assignments and DHCP autoconfiguration)
- How to Setup and Use the Cisco Configuration Engine
- How to Create and Manage Switch Clusters
- Performing Switch Administration
- Configuring Precision Time Protocol (PTP)
- Configuring PROFINET
- Common Industrial Protocol (CIP)
- Configuring SDM Templates
- Configuring Switch-Based Authentication
- Configuring IEEE 802.1x Port-Based Authentication
- MACsec
- Web-Based Authentication
- Configuring Smartports Macros
- Configuring SGACL Monitor Mode and SGACL Logging
- Configuring SGT Exchange Protocol over TCP (SXP) and Layer 3 Transport
- Configuring VLANs
- VLAN Trunking Protocol (VTP)
- Configuring Voice VLAN
- How to Configure Spanning Tree Protocol (STP)
- Configuring MSTP
- Configuring Optional Spanning-Tree Features
- Configuring Resilient Ethernet Protocol
- Configuring the FlexLinks and the MAC Address-Table Move Update
- Configuring DHCP
- Dynamic Address Resolution Protocol (ARP)
- Configuring IP Source Guard
- How to Configure Internet Group Management Protocol (IGMP) and Multicast VLAN Registration (MVR)
- Configuring Port-Based Traffic Control
- Configuring LLDP, LLDP-MED, and Wired Location Service
- Configuring SPAN and RSPAN
- One-to-one (1:1) Layer 2 Network Address Translation (NAT)
- How to Configure CDP
- Configuring UniDirectional Link Detection (UDLD)
- Configuring RMON
- Configuring System Message Logging
- Configuring Simple Network Management Protocol (SNMP)
- Network Security with ACLs
- Configuring Quality of Service (QoS)
- Configuring Static IP Unicast Routing
- Configuring IPv6 Host Functions
- Configuring Link State Tracking
- Configuring IP multicast routing
- Configuring Multicast Source Discovery Protocol (MSDP)
- Configuring Multicast Listener Discovery (MLD) snooping
- Configuring HSRP and VRRP
- Configuring IPv6 access control lists (ACLs)
- Configuring Embedded Event Manager (EEM)
- IP Unicast Routing
- IPv6 Unicast Routing
- Unicast Routing Overview
- Configuring Cisco IOS IP SLAs Operations
- Configuring Dying-Gasp
- How to Configure Enhanced Object Tracking
- Configuring MODBUS TCP
- Configuring Ethernet CFM
- Working with the Flash File System
- How to Configure EtherChannels
- Troubleshooting
- How to use a Secure Digital (SD) flash memory module (SD card)
Configuring Link State Tracking
Restrictions for Configuring Link State Tracking
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To use this feature, the switch must be running the LAN Base image.
■An interface that is defined as an upstream interface cannot also be defined as a downstream interface in the same or a different link state group. The reverse is also true.
■An interface cannot be a member of more than one link state group.
Information About Configuring Link State Tracking
Link State Tracking
Link state tracking, also known as trunk failover, is a feature that binds the link state of multiple interfaces. For example, link state tracking provides redundancy in the network when used with server NIC adapter teaming. When the server network adapters are configured in a primary or secondary relationship known as teaming, if the link is lost on the primary interface, connectivity is transparently changed to the secondary interface.
Note: An interface can be an aggregation of ports (an EtherChannel), a single physical port in access or trunk mode, or a routed port.
Figure 87 shows a network configured with link state tracking. To enable link state tracking, create a link state group, and specify the interfaces that are assigned to the link state group. In a link state group, these interfaces are bundled together. The downstream interfaces are bound to the upstream interfaces. Interfaces connected to servers are referred to as downstream interfaces, and interfaces connected to distribution switches and network devices are referred to as upstream interfaces.
The configuration in Figure 87 ensures that the network traffic flow is balanced as follows:
■For links to switches and other network devices
–Server 1 and server 2 use switch A for primary links and switch B for secondary links.
–Server 3 and server 4 use switch B for primary links and switch A for secondary links.
■Link state group 1 on switch A
–Switch A provides primary links to server 1 and server 2 through link state group 1. Port 1 is connected to server 1, and port 2 is connected to server 2. Port 1 and port 2 are the downstream interfaces in link state group 1.
–Port 5 and port 6 are connected to distribution switch 1 through link state group 1. Port 5 and port 6 are the upstream interfaces in link state group 1.
■Link state group 2 on switch A
–Switch A provides secondary links to server 3 and server 4 through link state group 2. Port 3 is connected to server 3, and port 4 is connected to server 4. Port 3 and port 4 are the downstream interfaces in link state group 2.
–Port 7 and port 8 are connected to distribution switch 2 through link state group 2. Port 7 and port 8 are the upstream interfaces in link state group 2.
■Link state group 2 on switch B
–Switch B provides primary links to server 3 and server 4 through link state group 2. Port 3 is connected to server 3, and port 4 is connected to server 4. Port 3 and port 4 are the downstream interfaces in link state group 2.
–Port 5 and port 6 are connected to distribution switch 2 through link state group 2. Port 5 and port 6 are the upstream interfaces in link state group 2.
■Link state group 1 on switch B
–Switch B provides secondary links to server 1 and server 2 through link state group 1. Port 1 is connected to server 1, and port 2 is connected to server 2. Port 1 and port 2 are the downstream interfaces in link state group 1.
–Port 7 and port 8 are connected to distribution switch 1 through link state group 1. Port 7 and port 8 are the upstream interfaces in link state group 1.
In a link state group, the upstream ports can become unavailable or lose connectivity because the distribution switch or router fails, the cables are disconnected, or the link is lost. These are the interactions between the downstream and upstream interfaces when link state tracking is enabled:
■If any of the upstream interfaces are in the link-up state, the downstream interfaces can change to or remain in the link-up state.
■If all of the upstream interfaces become unavailable, link state tracking automatically puts the downstream interfaces in the error-disabled state. Connectivity to and from the servers is automatically changed from the primary server interface to the secondary server interface.
As an example of a connectivity change from link state group 1 to link state group 2 on switch A, see Figure 87. If the upstream link for port 6 is lost, the link states of downstream ports 1 and 2 do not change. However, if the link for upstream port 5 is also lost, the link state of the downstream ports changes to the link-down state. Connectivity to server 1 and server 2 is then changed from link state group1 to link state group 2. The downstream ports 3 and 4 do not change state because they are in link-group 2.
■If the link state group is configured, link state tracking is disabled, and the upstream interfaces lose connectivity, the link states of the downstream interfaces remain unchanged. The server does not recognize that upstream connectivity has been lost and does not failover to the secondary interface.
You can recover a downstream interface link-down condition by removing the failed downstream port from the link state group. To recover multiple downstream interfaces, disable the link state group.
Figure 87 Typical Link State Tracking Configuration
Default Link State Tracking Configuration
There are no link state groups defined, and link state tracking is not enabled for any group.
How to Configure Link State Tracking
Configuring Link State Tracking
Monitoring and Maintaining Link State Tracking
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Configuration Examples for Configuring Link State Tracking
Displaying Link State Information: Examples
Use the show link state group command to display the link state group information. Enter this command without keywords to display information about all link state groups. Enter the group number to display information specific to the group. Enter the detail keyword to display detailed information about the group.
This is an example of output from the show link state group 1 command:
This is an example of output from the show link state group detail command:
Upstream Interfaces : Fa1/7(Dwn) Fa1/8(Dwn)
Downstream Interfaces : Fa1/3(Dis) Fa1/4(Dis) Fa1/5(Dis) Fa1/6(Dis)
Upstream Interfaces : Fa1/6(Dwn) Fa1/7(Dwn) Fa1/8(Dwn)
Downstream Interfaces : Fa1/2(Dis) Fa1/3(Dis) Fa1/4(Dis) Fa1/5(Dis)
Creating a Link State Group: Example
This example shows how to create a link state group and configure the interfaces:
Additional References
The following sections provide references related to switch administration:
Related Documents
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Standards
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No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature. |
MIBs
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To locate and download MIBs using Cisco IOS XR software, use the Cisco MIB Locator found at the following URL and choose a platform under the Cisco Access Products menu: http://cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml |
RFCs
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No new or modified RFCs are supported by this feature, and support for existing RFCs has not been modified by this feature. |
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