Why am I getting error message EZZ7904I?

Error message EZZ7904I indicates that an OSPF packet of the specified type was received, the packet failed to authenticate, and was discarded as a result of the failed authentication.

Verify the authentication type and authentication key specified for the appropriate interfaces on this and the source router. The types and keys must match in order for authentication to succeed.

The IP Configuration Guide makes the following points:

• In its description of the authentication_type parameter of the OSPF_INTERFACE statement, it states: "All hosts on the network must be configured with the same security scheme."

• In its description of the authentication_key parameter of the OSPF_INTERFACE statement, it states that "This value must be the same for all routers attached to a common medium."

If MD5 authentication is being used and OMPROUTE is stopped or recycled, ensure that it stays down for at least 3 times the largest configured dead router interval of the OSPF interfaces that use MD5 authentication, in order to age out the authentication sequence numbers on routers that did not recycle.

To display the value of the authentication type for an OSPF interface, enter the command DISPLAY TCPIP,tcpipjobname,OMPROUTE,OSPF,LIST,ALL. The output will include information similar to the following:

 EZZ7832I AREA CONFIGURATION                                             
 AREA ID          AUTYPE          STUB? DEFAULT-COST IMPORT-SUMMARIES?   
 0.0.0.0         1=PASSWORD       YES         1             YES         
 2.2.2.2         0=NONE           NO          N/A           N/A         

The value in the AUTYPE column is the method used for area authentication.