Extreme Networks ExtremeWare XOS 11.3, Manual

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Displaying ESRP Information
ExtremeWare XOS 11.3 Concepts Guide
475
Displaying ESRP Information
To view ESRP information, use the following command:
show esrp
Output from this command includes:
●
The operational state of an ESRP domain and the state of its neighbor
●
ESRP port configurations
To view more detailed information about an ESRP domain, use the following command and specify the
domain name:
show esrp {<name>}
Output from this command includes:
●
The operational state of an ESRP domain
●
ESRP election policy
●
ESRP tracking information
●
Timer statistics
●
State change information
To view ESRP counter information for a specific domain, use the following command:
show esrp {<name>} counters
To view ESRP-aware information for a specific domain (including the group number, MAC address for
the master, and the age of information) use the following command:
show esrp {<name>}
For more information about any of the commands used to enable, disable, or configure ESRP, refer to
the
ExtremeWare XOS Command Reference Guide .
Using ELRP with ESRP
Extreme Loop Recovery Protocol (ELRP) is a feature of ExtremeWare XOS that allows you to prevent,
detect, and recover from Layer 2 loops in the network. You can use ELRP with other protocols such as
ESRP.
With ELRP, each switch, except for the sender, treats the ELRP protocol data unit (PDU) as a Layer 2
multicast packet. The sender uses the source and destination MAC addresses to identify the packet it
sends and receives. When the sender receives its original packet back, that triggers loop detection and
prevention. Once a loop is detected, the loop recovery agent is notified of the event and takes the
necessary actions to recover from the loop. ELRP operates only on the sending switch; therefore, ELRP
operates transparently across the network.
How a loop recovers is dependent upon the protocol that uses the loop detection services provided by
ELRP. If you are using ELRP in an ESRP environment, ESRP may recover by transitioning the ESRP
domain from master to slave. This section describes how ESRP uses ELRP to recover from a loop and
the switch behavior.