Showing results for 
Search instead for 
Did you mean: 

GLBP generates "GLBP: API active virtual address x.x.x.x not found" messages



Core Issue

Gateway Load Balancing Protocol (GLBP) is similar to Hot Standby Router Protocol (HSRP) and Virtual Router Redundancy Protocol (VRRP) in function, providing redundancy and load balancing for IP networks. This ensures that user traffic immediately and transparently recovers from first hop router failures.  GLBP works by making use of a single virtual IP address that is configured as the default gateway on the hosts.

Beginning with Cisco IOS  Software Release 12.2, the GLBP implementation has been modified by removing it from the IP routing process with which it was coupled earlier. It is now a separate process. When required, the IP routing process queries the GLBP process to find if the address is already in use by GLBP.


GLBP generates the GLBP: API active virtual address x.x.x.x not found message if the x.x.x.x address being queried by the IP Routing process is not in use by GLBP. This message is seen if the debug glbp command is issued on the router. This is just an informational message indicating a normal situation, that GLBP is not already using the address being queried by the IP routing process, and it does not require any corrective action.

More Information

Debug glbp errors

To display debugging messages about Gateway Load Balancing Protocol (GLBP) error conditions, use the debug glbp errors command in privileged EXEC mode. To disable debugging output, use the no form of this command.

debug glbp errors
no debug glbp errors

Syntax Description

This command has no arguments or keywords.

Command Modes

Privileged EXEC

Command History







This command was introduced.




This command was integrated into Cisco IOS Release 12.2(15)T.



The following is sample output from the debug glbp errors command:

Router# debug glbp errors
GLBP Errors debugging is on
1d19h: GLBP: Fa0/0 API active virtual address not found
1d19h: GLBP: Fa0/0 API active virtual address not found
1d19h: GLBP: Fa0/0 API active virtual address not found





debug condition glbp


Displays debugging messages about GLBP that match specific conditions.


Related Commands