[Xorp-users] Re: help establishing OSPF adjacencies

Atanu Ghosh atanu@ICSI.Berkeley.EDU
Fri, 21 Oct 2005 02:53:59 -0700


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>>>>> "Nick" == Nick Feamster <feamster@lcs.mit.edu> writes:

    Nick> On Wed, Oct 19, 2005 at 03:27:03PM -0700, Atanu Ghosh wrote:
    >> of the routers neighbours are the designated router or backup
    >> designated router. This method should only be called if the the
    >> link type is Broadcast or NBMA, as these are the only link types
    >> that perform DR election. I assume that the link-type is set to
    >> point-to-multipoint (p2m), in when case the assert is signalling
    >> a programming error. The OSPF process will have exited. A stack
    >> backtrace might yield some clues.

    Nick> Yes, the link-type is p2m in our case, so perhaps this method
    Nick> should not be called?  It appears that the OSPF process dies
    Nick> completely as a result.  Sure, I will send along a backtrace.

This problem is now fixed in CVS.

    >> If the problem is reproducible with the latest code from CVS then
    >> the configuration files and some information about the topology
    >> would be useful.

    Nick> Simple topology:

    Nick> A <-> B <-> C, where both links are p2m links.  I've attached
    Nick> the configuration files.

I'v included a cut down configuration files that worked for me. I had to
modify the prefix length from 32 to 24 on the first router. Also you
shouldn't be setting discard to true on interfaces that you want to
route traffic through.

    >> If an attempt was made to add a route to the RIB and it failed
    >> you should error messages in the log.

    Nick> How do I ensure that routes are in the RIB, then?  Here's what
    Nick> I see in the log.

Use the show route command:
Xorp> show route table ipv4 unicast ospf 
Network 128.31.1.15/32
    Nexthop := 128.31.1.14
    Metric :=    10    Protocol := ospf    Interface := eth0    Vif := eth0

To see the final table:
Xorp> show route table ipv4 unicast final 
Network 128.31.1.0/24
    Nexthop := 128.31.1.13
    Metric :=     0    Protocol := connected Interface := eth0    Vif := eth0
Network 128.31.1.15/32
    Nexthop := 128.31.1.14
    Metric :=    10    Protocol := ospf    Interface := eth0    Vif := eth0

    Atanu.


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Content-Disposition: attachment; filename=p3
Content-Description: p3

	interfaces {
	    interface eth0 {
		vif eth0 {
		    address 128.31.1.13 {
			prefix-length: 24
		    }
		}
	    }
	}
	protocols {
	   ospf4 {
	       router-id: 128.31.1.13
	
	       area 0.0.0.0 {
		   interface eth0 {
	               link-type: "p2m"
		       vif eth0 {
			   address 128.31.1.13 {
				interface-cost: 5
				neighbour 128.31.1.14 {
				   router-id: 128.31.1.14
				}
			   }
		       }
		   }
	       }
	   }
       }
    }

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Content-Disposition: attachment; filename=p4
Content-Description: p4

	interfaces {
	    interface eth0 {
		vif eth0 {
		    address 128.31.1.14 {
			prefix-length: 24
		    }
		}
	    }
	}
	protocols {
	   ospf4 {
	       router-id: 128.31.1.14
	
	       area 0.0.0.0 {
		   interface eth0 {
	        	   link-type: "p2m"
		       vif eth0 {
			   address 128.31.1.14 {
				interface-cost: 5
				neighbour 128.31.1.13 {
				   router-id: 128.31.1.13
				}
				neighbour 128.31.1.15 {
				   router-id: 128.31.1.15
				}
			   }
		       }
		   }
	       }
	   }
       }
    }

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Content-Disposition: attachment; filename=p5
Content-Description: p5

	interfaces {
	    interface eth0 {
		vif eth0 {
		    address 128.31.1.15 {
			prefix-length: 24
		    }
		}
	    }
	}
	protocols {
	   ospf4 {
	       router-id: 128.31.1.15
	
	       area 0.0.0.0 {
		   interface eth0 {
	        	   link-type: "p2m"
		       vif eth0 {
			   address 128.31.1.15 {
				interface-cost: 5
				neighbour 128.31.1.13 {
				   router-id: 128.31.1.13
				}
				neighbour 128.31.1.14 {
				   router-id: 128.31.1.14
				}
			   }
		       }
		   }
	       }
	   }
       }
    }

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