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Now I'm testing a trivial UDP-based program with LVS, just a few bytes
in the packet.
Wireshark on the director shows the size of UDP packet is 520 bytes,
no overly large udp packet size message, and still I got "Destination
unreachable" ICMP.
I'm suspecting the network layer never pass these UDP packets to LVS...
Wang
On Thu, Nov 24, 2011 at 6:16 AM, Roger Littin <roger@xxxxxxxxxxxxx> wrote:
> Hi Wang,
>
> I have had similar problems where the director thinks the packet size is
> larger than mtu of the real server and sends back this message.
> Do you see anything in wireshark to indicate this. Overly large udp packet
> size?
>
> I think when the network layer hands off the packet to lvs, it may have
> already reassembled any fragments and then when lvs hands it back to the
> network layer, it is rejected because it is too large.
>
> Roger.
>
> On 24/11/2011, at 3:45 AM, wang yi wrote:
>
>> Yes, I tried to make my application listen to real IP / virtual IP /
>> INADDR_ANY, not working.
>>
>> But I think the problem isn't that.
>> As I mentioned in the original post, the LVS router seemed not
>> delivering client packets to real servers, instead, it generated ICMP
>> message(Destination unreachable), and the packets may be dropped.
>>
>> Wang
>>
>> On Wed, Nov 23, 2011 at 6:30 PM, Roger Littin <roger@xxxxxxxxxxxxx> wrote:
>>> Hi,
>>>
>>> I think you need to set your application on the real servers to listen to
>>> the udp port on all ip's or at least the real ip and then it needs to
>>> respond to the client on the vip.
>>>
>>> Roger.
>>>
>>> On 23/11/2011, at 10:06 PM, wang yi wrote:
>>>
>>>> Hi, all
>>>> I've set up LVS with DR mode for Apache, it worked OK. Then I set
>>>> up another Virtual Service for an UDP based program on the same boxes,
>>>> but it won't work.
>>>>
>>>> Running Wireshark on the director showed that it got the UDP
>>>> packets from client, but responsed these packets with an ICMP message,
>>>> Destination unreachable (Port unreachable)
>>>>
>>>> I cannot find any information about this. Anything special about
>>>> UDP based program?
>>>> Regards.
>>>> Leo
>>>>
>>>> _______________________________________________
>>>> Please read the documentation before posting - it's available at:
>>>> http://www.linuxvirtualserver.org/
>>>>
>>>> LinuxVirtualServer.org mailing list - lvs-users@xxxxxxxxxxxxxxxxxxxxxx
>>>> Send requests to lvs-users-request@xxxxxxxxxxxxxxxxxxxxxx
>>>> or go to http://lists.graemef.net/mailman/listinfo/lvs-users
>>>
>>>
>>> _______________________________________________
>>> Please read the documentation before posting - it's available at:
>>> http://www.linuxvirtualserver.org/
>>>
>>> LinuxVirtualServer.org mailing list - lvs-users@xxxxxxxxxxxxxxxxxxxxxx
>>> Send requests to lvs-users-request@xxxxxxxxxxxxxxxxxxxxxx
>>> or go to http://lists.graemef.net/mailman/listinfo/lvs-users
>>>
>>
>> _______________________________________________
>> Please read the documentation before posting - it's available at:
>> http://www.linuxvirtualserver.org/
>>
>> LinuxVirtualServer.org mailing list - lvs-users@xxxxxxxxxxxxxxxxxxxxxx
>> Send requests to lvs-users-request@xxxxxxxxxxxxxxxxxxxxxx
>> or go to http://lists.graemef.net/mailman/listinfo/lvs-users
>
>
> _______________________________________________
> Please read the documentation before posting - it's available at:
> http://www.linuxvirtualserver.org/
>
> LinuxVirtualServer.org mailing list - lvs-users@xxxxxxxxxxxxxxxxxxxxxx
> Send requests to lvs-users-request@xxxxxxxxxxxxxxxxxxxxxx
> or go to http://lists.graemef.net/mailman/listinfo/lvs-users
>
_______________________________________________
Please read the documentation before posting - it's available at:
http://www.linuxvirtualserver.org/
LinuxVirtualServer.org mailing list - lvs-users@xxxxxxxxxxxxxxxxxxxxxx
Send requests to lvs-users-request@xxxxxxxxxxxxxxxxxxxxxx
or go to http://lists.graemef.net/mailman/listinfo/lvs-users
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