[Xorp-users] [xorp-users] OSPFv2 problem: no matching neighbor found

[Atanu Ghosh]

Hi,

In OSPF some packets such as the hello packets are multicast and other
packets such as the data description packets are unicast. The source
address in a packet is used to demultiplex a packet and associate it
with a neighbour. I notice from the output of "show ospf4 neighbour"
that you seem to be using tunnels. What may be happening is that the
hello packets that are multicast are being received with the orignal
source address provided by OSPF, the source address of unicast packets
may be changed by the tunnel, which could explain why they are not
recognised.

Try running tcpdump on router A and check the source addresses of
received packets.

	Atanu.

>>>>> "Yue" == Yue Li <yueli.m at gmail.com> writes:

    Yue> ---------- Forwarded message ----------
    Yue> From: Yue Li <yueli.m at gmail.com>
    Yue> Date: 2008-1-6 ÉÏÎç1:51
    Yue> Subject: Re: [Xorp-users] [xorp-users] OSPFv2 problem: no matching
    Yue> neighbor found
    Yue> To: atanu at icsi.berkeley.edu


    Yue> Hi,
    Yue> Thanks for your reply.
    Yue> The topology used is as follow:

    Yue> +---+ (10.10.0.9)       (10.10.0.10)+---+
    Yue> | A |----------------------------------------- | B |
    Yue> +---+                                         +---+
    Yue> |(10.10.0.1)                                |  (10.10.0.6)
    Yue> |                                               |
    Yue> |                                               |  (10.10.0.5)
    Yue> |                           (10.10.0.2) +----+
    Yue> - --------------------------------------------| C |
    Yue> +----+

    Yue> Router A (id: 10.10.0.1), Router B (id: 10.10.0.10) and Router C (id:
    Yue> 10.10.0.5),
    Yue> each has two neighbors.

    Yue> On Router A:
    Yue> show ospf4 neighbor:
    Yue> Address         Interface             State      ID              Pri  Dead
    Yue> 10.10.0.2        tun0/tun0              ExStart   10.10.0.5        128    31
    Yue> 10.10.0.10       tun1/tun1              ExStart   10.10.0.10       128    33

    Yue> show ospf4 database:
    Yue> OSPF link state database, Area 0.0.0.0
    Yue> Type       ID               Adv Rtr           Seq      Age  Opt  Cksum  Len
    Yue> Router  *10.10.0.1        10.10.0.1        0x80000001    78  0x2  0xad78  48


    Yue> 2008/1/4, Atanu Ghosh <atanu at icsi.berkeley.edu>:
    >> Hi,
    >> 
    >> The XORP OSPF will not accept data description packets from an unknown
    >> neighbour (this is a protocol requirement).
    >> 
    >> Can you send the output of the "show ospf4 neighbor" command?
    >> 
    >> Atanu.
    >> .
    >> >>>>> "Yue" == Yue Li <yueli.m at gmail.com> writes:
    >> 
    Yue> Hi, everyone I am doing some experiment with ospfv2. The
    Yue> problem is xorp is keep saying "no matching neighbor found"
    Yue> when receiving database description packets.  When I show ospf
    Yue> database through xorpsh, there is nothing.
    >> 
    Yue> Can you give me any clues?  Thanks!
    >> 
    Yue> _______________________________________________ Xorp-users
    Yue> mailing list Xorp-users at xorp.org
    Yue> http://mailman.ICSI.Berkeley.EDU/mailman/listinfo/xorp-users
    >>