[Xorp-users] BadPeer ...: Area ... not handled by eth0/eth0

Fri Feb 29 09:19:57 PST 2008

Hi,

OSPF divides the network into areas, each area has a 32 bit area ID, the
areas are *independent* of subnets.

Areas are structured in a heirarchy, area 0.0.0.0 also called
the backbone, is the top of the heirarchy and all other areas are
connected to the backbone (there is an exception but we don't need to
worry about that here). Figure 6 in RFC 2328
<http://www.ietf.org/rfc/rfc2328.txt> has an example topology.

In order for neighbouring OSPF routers to communcate they must be
configured to be in the same area. Every OSPF packet contains a header
and one of the fields in the header is the area ID. The warning messages
that you are seeing is OSPF reporting that it was seeing packets on
eth0 from area 217.64.164.12, but your configuration has eth0 in area
0.0.0.0. It looks like your "upstream" has not connected you directly to
the backbone but has put you in a separate area 217.64.164.12.

If you change your configuration replacing area 0.0.0.0 with
217.64.164.12 then you should form adjacencies with your "upstream".

       Atanu.

>>>>> "Dirk" == Dirk H Schulz <dirk.schulz at kinzesberg.de> writes:

    Dirk> Hi Atanu, thanks for helping.

    Dirk> I am not sure I understand you right. You say that on eth0
    Dirk> ospf packets from a router arrive that is in subnet
    Dirk> 217.64.164.128? I am logging all traffic at the moment, and
    Dirk> ospf packets on eth0 arrive only from 217.64.170.233 which is
    Dirk> the address of the upstream router (I checked on my first
    Dirk> router).

    Dirk> And I do not understand
    >> area 217.64.164.128, which in your configuration is area 0.0.0.0
    Dirk> In my configuration this is area 0.0.0.1 - do you think it
    Dirk> SHOULD be area 0.0.0.0? I thought that area 0.0.0.0 always is
    Dirk> the area with the upstream connection.

    Dirk> Thanks again for your help.

    Dirk> Dirk

    Dirk> --On 28. Februar 2008 11:40:13 -0800 Atanu Ghosh
    Dirk> <atanu at icsi.berkeley.edu> wrote:

    >> Hi,
    >> 
    >> The message is telling you that OSPF packets are being received
    >> on eth0/eth0 from a router which is in area 217.64.164.128, which
    >> in your configuration is area 0.0.0.0. If you change your
    >> configuration to area 217.64.164.128 you will probably be able to
    >> peer with your upstream routers.
    >> 
    >> Atanu.
    >> 
    >>>>>>> "Dirk" == Dirk H Schulz <dirk.schulz at kinzesberg.de> writes:
    >>
    Dirk> Hi Folks, I am new to running routers on my own and new to
    Dirk> Xorp and OSPF.
    >>
    Dirk> I have setup two routers using ospf. They are two
    Dirk> communication with two upstream routers using ospf as
    Dirk> well. Now my own routers find each other as neighbors (the do
    Dirk> not find the upstream routers, but that is a problem I have to
    Dirk> solve with the upstream provider, I think).
    >>
    Dirk> They seem to work, my routers, but both put out the following
    Dirk> message every few seconds:
    >>
    Dirk> BadPeer from line 379 of peer.cc: Area 217.64.164.128 not
    Dirk> handled by eth0/eth0
    >>
    Dirk> I have not found anything relating in the docs, in Google nor
    Dirk> elsewhere.
    >>
    Dirk> 217.64.164.128 is the subnet used for area 0.0.0.1 on
    Dirk> interface bond0 on both routers. I do not understand why it
    Dirk> should be handled by eth0 which has a setting of
    Dirk> 217.64.170.238/29 resp. 217.64.170.230/29.
    >>
    Dirk> This is the configuration of one router, the other is nearly
    Dirk> identical (just other IP addresses):
    >>  >> interfaces { restore-original-config-on-shutdown: true
    >> >>
    >> >> interface eth0 { description: "external (area0) interface" >>
    >> disable: false default-system-config }
    >> >>
    >> >> interface eth1 { description: "inter router interface"
    >> disable: >> false default-system-config }
    >> >>
    >> >> interface bond0 { description: "area1 bonding interface"
    >> disable: >> false default-system-config } /* interface bond1 {
    >> description: >> "area2 bonding interface" disable: false
    >> default-system-config } >> */ }
    >> >>
    >> >> fea { unicast-forwarding4 { disable: false forwarding-entries
    >> { >> retain-on-startup: false retain-on-shutdown: false } } >>
    >> unicast-forwarding6 { disable: true forwarding-entries { >>
    >> retain-on-startup: false retain-on-shutdown: false } } }
    >> >>
    >> >> protocols { ospf4 { router-id: 217.64.170.238
    >> >>
    >> >> area 0.0.0.0 { area-type: "normal" interface eth0 { vif eth0 {
    >> >> address 217.64.170.238 { priority: 128 hello-interval: 5 >>
    >> router-dead-interval: 15 interface-cost: 1 retransmit-interval: 2
    >> >> transit-delay: 1 disable: false } } } interface eth1 { vif
    >> eth1 { >> address 192.168.11.1 { priority: 128 hello-interval: 5
    >> >> router-dead-interval: 15 interface-cost: 2
    >> retransmit-interval: 2 >> transit-delay: 1 disable: false } } } }
    >> >>
    >> >> area 0.0.0.1 { area-type: "normal" interface bond0 { vif bond0
    >> { >> address 217.64.164.129 { priority: 128 hello-interval: 5 >>
    >> router-dead-interval: 15 interface-cost: 2 retransmit-interval: 2
    >> >> transit-delay: 1 disable: false } } } } /* area 0.0.0.2 { >>
    >> area-type: "normal" interface bond1 { vif bond1 { address >>
    >> 217.64.170.60 } } } */ } }
    >> 
    Dirk> Any ideas? Every hint or help is appreciated.
    >>
    Dirk> Thanks in advance,
    >>
    Dirk> Dirk
    >>
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