Re: peth1: received packet with own address as source address

[Jerone Young <jyoung5@us.ibm.com>]

On Mon, 2005-10-17 at 16:04 -0500, Andrew Theurer wrote:
> Arnd Schmitter wrote:
> 
> > David F Barrera wrote:
> >
> >> On Mon, 2005-10-17 at 20:50 +0200, Arnd Schmitter wrote:
> >>  
> >>
> >>> David F Barrera wrote:
> >>>    
> >>>
> >>>> peth1: received packet with  own address as source address
> >>>>
> >>>> Is this something that I should care about? I don't see an obvious
> >>>> impact to the machine.          
> >>>
> >>> This means normaly two things: Packets you send out are returning or 
> >>> there is another PC with the same address.
> >>> The Linuxkernel drops this packets as he think its a knd of address 
> >>> spoofing.
> >>> If all networking is working fine you will only have a minimal 
> >>> impact on performance. But it could indicate that something with 
> >>> your network configuration is wrong
> >>>     
> >>
> >> Arnd, thanks for your response. My network configuration appears to be
> >> OK; it is simple, one NIC and its IP address, and everything seems to be
> >> working well. Also, there are no two machines with the same address. So,
> >> I am wondering if this is a problem with Xen. I have opened up a
> >> bugzilla report, as I would like to have a definitive answer as to
> >> whether this is a bug or a network configuration issue.
> >>
> >> http://bugzilla.xensource.com/bugzilla/show_bug.cgi?id=339
> >>   
> >
> >
> > Only one NIC and peth1 ??
> >
> > Take a look at your ifconfig output. Maybe there are two 
> > Virtual-Interfaces witch the same MAC.
> 
> Unless the network-bridge script has changed the generated mac for eth0 
> (which gets renamed to peth0), all systems probably have the same mac 
> for peth0 & xen-br0: fe:ff:ff:ff:ff:ff.  I have tried using unique macs 
> (for just peth0, vif0.0, and xen-br0, other vifs still have fe:ff...), 
> and these messages disappear.  So, why would the mac for a veth0 or 
> xen-br0 get sent to another system?  Not sure, since they should not 
> have an ip address, and should not respond to an arp request.  I do 
> notice that peth0 has 'noarp' but xen-br0 does not.  Perhaps adding 
> noarp to xen-br0 will fix this.

This might just be it. We are no longer seeing it if we start xend with
#export netdev=eth1
#xend start
#ifconfig xen-br0 -arp

on an IBM HS20 blade that showed the error earlier. Could anyone else
seeing this try this to confirm this amongst more setups.


> 
> -Andrew
> 
> 
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-- 
Jerone Young
IBM Linux Technology Center
jyoung5@us.ibm.com
512-838-1157 (T/L: 678-1157)