notes: Common OSPF Error Messages

This section discusses some of the common error messages in OSPF. Some messages are an indication of a bug, but those messages are not discussed in this section. Some messages also are self-explanatory, such as this one:

Warning: Router is currently an ASBR while having only one area which is a stub area

This warning message means that you are trying to redistribute into a stub area.

Here is the list of error messages that will be discussed in this section:

• "Unknown routing protocol"
  
  
  This error message is generated when the router ospf 1 command is typed on a router to configure OSPF. This message means that the software or the hardware does not support OSPF. Usually low-end platforms, such as 1000 and 1600 series routers, need a special image (that is, the Plus feature set) to run OSPF. Some low-end platforms, such as 800 series routers, do not support OSPF.
  
  
• "OSPF: Could not allocate router id"
  
  
  This message appears in two situations:
   - No up/up interface with a valid IP address
   - Not enough up interfaces with a valid IP address for multiple OSPF processes

• OSPF requires a valid IP address that is up/up so that it can allocate a router ID for the OSPF process. The IP address must be assigned on an up/up interface. If a router fails to allocate router IDs, OSPF will not function. This problem can be corrected by using loopback addresses.
  
  
  The loopback interface solution works for both situations. Just configure a loopback interface for one process. If you are trying to run more than one process, you might need more than one loopback interface.

• "%OSPF-4-BADLSATYPE"
  This is normal if the neighboring router is sending the multicast OSPF (MOSPF) packet.
  Solution:
  router ospf 1  
  ignore lsa mospf
   
• "%OSPF-4-ERRRCV"
  
  
  Three common types of this message can occur:
  
  
  1.  Mismatch area ID
        
  %OSPF-4-ERRRCV: Received invalid packet: mismatch area ID, from backbone area must be virtual-link but not found from 170.170.3.3, Ethernet0
  
  
  This means that the neighbor's interface connecting to this interface is in area 0 but that this interface is not in area 0. In this situation, the router will not form an OSPF adjacency with the neighbor that this packet comes from. This also happens if one side's virtual link is misconfigured.
  
  
  To avoid these messages, make sure that both sides have the same area ID by checking the network statement under OSPF in the router configuration. For example, if the link 10.10.10.0/24 between two routers should be in area 1, make sure that the network statement on both routers includes this particular link in area 1.
  
  
  If a virtual link is configured, double-check the configuration for virtual link.
  
  
  %OSPF-4-ERRRCV: Received invalid packet: Bad Checksum from 144.100.21.141, TokenRing0/0 
  
  
  2.  Bad checksum
  This means that OSPF encountered an error in a packet that was received. This is because the OSPF checksum does not match the OSPF packet that was received by this router.
  
  
  This problem has three causes:
• A device between the neighbors, such as a switch, is corrupting the packet.
• The sending router's packet is invalid. In this case, either the sending router's interface is bad or a software bug is causing the error.
• The receiving router is calculating the wrong checksum. In this case, either the receiving router's interface is bad or a software bug is causing the error. This is the least likely cause of this error message.
  
  
  This problem can be difficult to troubleshoot, but you can start with the following solution, which is effective in 90 percent of cases. It's important that you follow the steps in order:

Step 1. Change the cable between the routers. For the example given in this section, this would be the router that is sending the bad packet (144.100.21.141) and the router that is complaining about these bad packets.

Step 2. If Step 1 doesn't fix the problem, use a different port on the switch between the routers.

Step 3. If Step 2 doesn't fix the problem, connect the routers directly using a cross-over cable. If you receive no further messages, the switch most likely is corrupting the packet.

 

If none of these steps solves the problem, contact the Cisco Technical Assistance Center (TAC) and work with an engineer to look for a bug in Cisco IOS Software or to obtain a possible Return Material Authorization (RMA) for partial or full parts replacement.

• 
  
  
  
  3.  OSPF not enabled on the receiving interface
  
  
       %OSPF-4-ERRRCV: Received invalid packet: OSPF not enabled on interface from 141.108.16.4, Serial0.100 
  The router generating this message received a packet from 141.108.16.4 on Serial0.100, but OSPF is not enabled on the Serial0.100 interface. This message is generated only once for a non-OSPF interface.