[Xorp-users] Xorp does not see ospf hello packets in a gre

Ricardo Sepulveda reesesoliarie at yahoo.com
Tue May 24 17:29:58 PDT 2011


Sorry for taking so long on this.

With no GRE tunnel between Xorp1 and Xorp2, OSPF can neighbor.
Dead timers reset at default intervals and I can ping between both clients
across Xorp1 and Xorp2.
I originally thought this was a DMVPN/OpenNHRP issue but I have the same
problem in a simple GRE tunnel.
**I can provide the details on how the DMVPN/OpenNHRP was configured to work
if someone wants them but I did not get them to run in an Xorp<-->Xorp
config.
**It only runs in a Cisco<-->Xorp configuration for me right now.

NO GRE CONFIGURATION:
Client1<----->Xorp1<----->Xorp2<----->Client2

GRE CONFIGURATION:
Client1<----->Xorp1<=GRE=>Xorp2<----->Client2

When the GRE is established there are OSPF hello's moving from each side to
the other but neither side will Neighbor.

TCPDUMP from GRE tunnel
00:55:35.700463 IP 10.254.254.2 > 224.0.0.5: OSPFv2, Hello, length 44
00:55:44.112852 IP 10.254.254.3 > 224.0.0.5: OSPFv2, Hello, length 44

Xorp box is Fedora 13 Linux 2.6.33.3-85.fc13.i686.PAE #1 SMP

I've added the config for Xorp and the configs for the GRE.
Is this just a bad configuration on my part?

Thanks for taking a look.
Ricardo
**********************************************

IP SETUP
Client1
172.16.2.14/24

Xorp1
eth0_172.16.2.254/24
eth1_10.1.1.2/24
gre1_10.254.254.2/24

Xorp2
eth0_10.1.1.3/24
eth1_192.168.247.254/24
gre1_10.254.254.3/24

Client2
192.168.247.3

I set up a GRE tunnel with the following commands:
Xorp1
ip tunnel add gre1 mode gre remote 10.1.1.3 key60 ttl 64
ip addr add 10.254.254.2/24 dev gre1
ip link set gre1 multicast on
ip link set gre1 mtu 1400
ip link set gre1 up

Xorp2
ip tunnel add gre1 mode gre remote 10.1.1.2 key 60 ttl 64
ip addr add 10.254.254.3/24 dev gre1
ip link set gre1 multicast on
ip link set gre1 mtu 1400
ip link set gre1 up

<<I used the same configuration on each Xorp box with the different IP's and
Router ID's.>>

/* XORP configuration file
 *
 * Configuration format: 1.1
 * XORP version: 1.8.3
 * Date: 2011/05/24 00:24:27.709647
 * Host: localhost.localdomain
 * User: root
 */

protocols {
    fib2mrib {
        disable: false
    }
    igmp {
        disable: false
        interface gre1 {
            vif gre1 {
                disable: false
                version: 3
                enable-ip-router-alert-option-check: false
                query-interval: 125
                query-last-member-interval: 1
                query-response-interval: 10
                robust-count: 2
            }
        }
        interface eth1 {
            vif eth1 {
                disable: false
                version: 3
                enable-ip-router-alert-option-check: false
                query-interval: 125
                query-last-member-interval: 1
                query-response-interval: 10
                robust-count: 2
            }
        }
    }
    ospf4 {
        router-id: 192.168.247.254
        rfc1583-compatibility: false
        ip-router-alert: false
        area 0.0.0.1 {
            area-type: "normal"
            interface gre1 {
                link-type: "broadcast"
                vif gre1 {
                    address 10.254.254.3 {
                        priority: 128
                        hello-interval: 10
                        router-dead-interval: 40
                        interface-cost: 1
                        retransmit-interval: 5
                        transit-delay: 1
                        disable: false
                    }
                }
            }
            interface eth1 {
                link-type: "broadcast"
                vif eth1 {
                    address 192.168.247.254 {
                        priority: 128
                        hello-interval: 10
                        router-dead-interval: 40
                        interface-cost: 1
                        retransmit-interval: 5
                        transit-delay: 1
                        disable: false
                    }
                }
            }
        }
    }
    pimsm4 {
        disable: false
        interface gre1 {
            vif gre1 {
                disable: false
                dr-priority: 1
                hello-period: 30
                hello-triggered-delay: 5
            }
        }
        interface eth1 {
            vif eth1 {
                disable: false
                dr-priority: 1
                hello-period: 30
                hello-triggered-delay: 5
            }
        }
        interface "register_vif" {
            vif "register_vif" {
                disable: false
                dr-priority: 1
                hello-period: 30
                hello-triggered-delay: 5
            }
        }
    }
    static {
        disable: false
    }
}
fea {
    unicast-forwarding4 {
        disable: false
    }
}
interfaces {
    restore-original-config-on-shutdown: false
    interface gre1 {
        description: ""
        disable: false
        discard: false
        unreachable: false
        management: false
        parent-ifname: ""
        iface-type: ""
        vid: ""
        vif gre1 {
            disable: false
            address 10.254.254.3 {
                prefix-length: 24
                disable: false
            }
        }
    }
    interface eth1 {
        description: ""
        disable: false
        discard: false
        unreachable: false
        management: false
        parent-ifname: ""
        iface-type: ""
        vid: ""
        vif eth1 {
            disable: false
            address 192.168.247.254 {
                prefix-length: 24
                disable: false
            }
        }
    }
}
plumbing {
    mfea4 {
        disable: false
        interface gre1 {
            vif gre1 {
                disable: false
            }
        }
        interface eth1 {
            vif eth1 {
                disable: false
            }
        }
        interface "register_vif" {
            vif "register_vif" {
                disable: false
            }
        }
    }
    rib {
    }
}
rtrmgr {
    config-directory: "/etc/xorp"
    load-file-command: "fetch"
    load-file-command-args: "-o"
    load-ftp-command: "fetch"
    load-ftp-command-args: "-o"
    load-http-command: "fetch"
    load-http-command-args: "-o"
    load-tftp-command: "sh -c 'echo Not implemented 1>&2 && exit 1'"
    load-tftp-command-args: ""
    save-file-command: "sh -c 'echo Not implemented 1>&2 && exit 1'"
    save-file-command-args: ""
    save-ftp-command: "sh -c 'echo Not implemented 1>&2 && exit 1'"
    save-ftp-command-args: ""
    save-http-command: "sh -c 'echo Not implemented 1>&2 && exit 1'"
    save-http-command-args: ""
    save-tftp-command: "sh -c 'echo Not implemented 1>&2 && exit 1'"
    save-tftp-command-args: ""
}






-----Original Message-----
From: Ben Greear [mailto:greearb at candelatech.com] 
Sent: Thursday, May 12, 2011 4:32 PM
To: Ricardo Sepulveda
Cc: xorp-users at xorp.org
Subject: Re: [Xorp-users] Xorp does not see ospf hello packets in a gre

On 05/12/2011 10:30 AM, Ricardo Sepulveda wrote:
>
>
> Thanks for the reply.
>
> I am using:
> Fedorea Core 13 2.6.34.8-68
> Xorp 1.8.3 release 1. fc13
>
> There was nothing odd that I saw in the system logs. I cant grab out the
Xorp logs at the moment but as it ran Xorp I did not see any outstanding
errors.
> I did run wireshark and I could see the hello's comming in over the gre
interface. Thats how I know the packets are comming in.  Looking at the
ospf4 details in Xorp I could see the dead timer counting down while on the
Cisco router I could see the timer reset every 10 seconds.
>
> Using the same exact configuraton outside of the gre/dmvpn tunnle
everything works just fine.

There might be some issue with FEA dealing with tunnels.  You could try
adding
some debugging to it's packet reception logic to see if it's even getting
packets.  I think fea/data_plane/io/io_tcpudp_socket.cc might be a good
place to start, but it's been a while since I poked around in that code.

If you can reproduce the problem with xorp <-> xorp, and provide some good
details on how to configure the gre/dmvpn tunnel in Linux, then
I or someone else might get time to debug it.

Thanks,
Ben


>
>
> Ricardo
>
>
>
>
>
> From: xorp-users-bounces at xorp.org [mailto:xorp-users-bounces at xorp.org] On
Behalf Of xorp-users-request at xorp.org
> Sent: Wednesday, May 11, 2011 12:00 PM
> To: xorp-users at xorp.org
> Subject: EXT :Xorp-users Digest, Vol 62, Issue 6
>
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> Today's Topics:
>
>    1. Xorp does not see ospf hello packets in a gre tunnel
>        (Ricardo Sepulveda)
>    2. Re: Xorp does not see ospf hello packets in a gre    tunnel
>        (Ben Greear)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Tue, 10 May 2011 15:40:49 -0700 (PDT)
> From: Ricardo Sepulveda<reesesoliarie at yahoo.com>
> Subject: [Xorp-users] Xorp does not see ospf hello packets in a gre
>      tunnel
> To: "xorp-users at xorp.org"<xorp-users at xorp.org>
> Message-ID:<70710.19958.qm at web30803.mail.mud.yahoo.com>
> Content-Type: text/plain; charset=utf-8
>
> Hi Everyone,
>
> I am having issues with Xorp not seeing the hello packets from a
neighbored Cisco router over a gre opennhrp/dmvpn tunnel.
>
> In my setup the Xorp and Cisco router neighbor up fine over the gre tunnel
(ethernet)?and allow data to pass across.
> The issue is that Xorp will not see any of the hello packets that come
across the tunnel from the Cisco router after the successful convergence.?
Data moves until the dead timer runs down. It then starts back up after the
systems re-converge. ?
> ?
> The Cisco accepts the hello's from Xorp over the tunnel and I can see the
hello's come into the Xorp interface from the Cisco.?
> ?
> As a test I?ve played with the hello intervals and router dead intervals
on the Cisco and Xorp systems but it has made no difference.
>
> With no tunnels the systems converge and the dead timers update regularly.
>
> I have tested this in Quaga but I do not have this issue with the
hello's.?
> ?
> Any ides on what the issue might be?
> ?
> Thanks
> Ricardo S.
>
>
>
> ------------------------------
>
> Message: 2
> Date: Tue, 10 May 2011 15:50:26 -0700
> From: Ben Greear<greearb at candelatech.com>
> Subject: Re: [Xorp-users] Xorp does not see ospf hello packets in a
>      gre    tunnel
> To: Ricardo Sepulveda<reesesoliarie at yahoo.com>
> Cc: "xorp-users at xorp.org"<xorp-users at xorp.org>
> Message-ID:<4DC9C132.3060001 at candelatech.com>
> Content-Type: text/plain; charset=UTF-8; format=flowed
>
> On 05/10/2011 03:40 PM, Ricardo Sepulveda wrote:
>> Hi Everyone,
>>
>> I am having issues with Xorp not seeing the hello packets from a
neighbored Cisco router over a gre opennhrp/dmvpn tunnel.
>>
>> In my setup the Xorp and Cisco router neighbor up fine over the gre
tunnel (ethernet) and allow data to pass across.
>> The issue is that Xorp will not see any of the hello packets that come
across the tunnel from the Cisco router after the successful convergence.
Data moves until the dead timer runs down. It then starts back up after the
systems re-converge.
>>
>> The Cisco accepts the hello's from Xorp over the tunnel and I can see the
hello's come into the Xorp interface from the Cisco.
>>
>> As a test I?ve played with the hello intervals and router dead intervals
on the Cisco and Xorp systems but it has made no difference.
>>
>> With no tunnels the systems converge and the dead timers update
regularly.
>>
>> I have tested this in Quaga but I do not have this issue with the
hello's.
>>
>> Any ides on what the issue might be?
>
> Please let us know the OS, kernel version, xorp version, and perhaps the
xorp
> logs...
>
> You might try poking through the logs yourself to see if you see anything
interesting...
>
> You could also sniff the interface to make sure pkts are being properly
received by
> the OS.
>
> Thanks,
> Ben
>
>>
>> Thanks
>> Ricardo S.
>>
>> _______________________________________________
>> Xorp-users mailing list
>> Xorp-users at xorp.org
>> http://mailman.ICSI.Berkeley.EDU/mailman/listinfo/xorp-users
>
>


-- 
Ben Greear <greearb at candelatech.com>
Candela Technologies Inc  http://www.candelatech.com





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