I''ve been looking into an issue were in the message file I see: Apr 28 11:43:10 kdell kernel: peth0: received packet with own address as source address Trying to match the time stamp in the message file to a packet trace captured by ethereal, I found that the offending packets are of the type ICMPv6 Multicast Listener Report Message v2, ICMPv6 Neighbor Solicitation, or ICMPv6 Router Solicitation packets. It looks like these packets are sent every time a network interface is brought up. In this case it is when peth0 is brought up from the network-bridge script since the MAC address is fe:ff:ff:ff:ff:ff. When a peth0 comes up, all other machines with a peth0 up and running will receive the packets and log the messages. Is this an issue of concern? Thanks, Kirk _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
> I''ve been looking into an issue were in the message file I see: > Apr 28 11:43:10 kdell kernel: peth0: received packet with > own address as source address > > Trying to match the time stamp in the message file to a > packet trace captured by ethereal, I found that the offending > packets are of the type > ICMPv6 Multicast Listener Report Message v2, ICMPv6 Neighbor > Solicitation, or ICMPv6 Router Solicitation packets. It > looks like these packets are sent every time a network > interface is brought up. In this case it is when peth0 is > brought up from the network-bridge script since the MAC > address is fe:ff:ff:ff:ff:ff. When a peth0 comes up, all > other machines with a peth0 up and running will receive the > packets and log the messages. > > Is this an issue of concern?It''s not of particular concern, but it would be nice to make them stop. Is it the ''ip link set dev X up'' line that causes the packet to be sent? Does anyone know how to make them stop? Thanks, Ian _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Nivedita Singhvi
2006-Apr-29 18:00 UTC
Re: [Xen-devel] peth0 received packet on own address
Ian Pratt wrote:>>I''ve been looking into an issue were in the message file I see: >>Apr 28 11:43:10 kdell kernel: peth0: received packet with >>own address as source address >> >>Trying to match the time stamp in the message file to a >>packet trace captured by ethereal, I found that the offending >>packets are of the type >>ICMPv6 Multicast Listener Report Message v2, ICMPv6 Neighbor >>Solicitation, or ICMPv6 Router Solicitation packets. It >>looks like these packets are sent every time a network >>interface is brought up. In this case it is when peth0 is >>brought up from the network-bridge script since the MAC >>address is fe:ff:ff:ff:ff:ff. When a peth0 comes up, all >>other machines with a peth0 up and running will receive the >>packets and log the messages. >> >>Is this an issue of concern? > > > It''s not of particular concern, but it would be nice to make them stop. > > Is it the ''ip link set dev X up'' line that causes the packet to be sent? > Does anyone know how to make them stop?Not compiling in support for MLDv2, etc in the kernel can make that stop, but distro kernels I believe turn that on by default. But those broadcasts aren''t the problem, the fact is that the physical address needs to be unique across the network. Someone might conceivably want to run advanced routing functions on a guest domain, or on multiple systems in the network, in which case it needs to send out those packets. We shouldn''t be doing all of those things (peth0) on the guest OSs - we had gone to some pains to make sure the MAC was unique across the system - have we regressed in that due to the -xen kernel or some other reason? We also need to ensure that the MAC is unique on the subnet, if this isn''t a case of a guest domain having accidentally a duplicate MAC. I haven''t caught up with the changes in the unstable kernel in the last few weeks, looking into it.. thanks, Nivedita _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Nivedita Singhvi
2006-Apr-29 23:41 UTC
Re: [Xen-devel] peth0 received packet on own address
Nivedita Singhvi wrote:> Ian Pratt wrote: > >>> I''ve been looking into an issue were in the message file I see: Apr >>> 28 11:43:10 kdell kernel: peth0: received packet with own address as >>> source address >>> >>> Trying to match the time stamp in the message file to a packet trace >>> captured by ethereal, I found that the offending packets are of the type >>> ICMPv6 Multicast Listener Report Message v2, ICMPv6 Neighbor >>> Solicitation, or ICMPv6 Router Solicitation packets. It looks like[snip]> Not compiling in support for MLDv2, etc in the kernelI should have also mentioned, although this is somewhat tangential to main issue - that if you are not using IPv6, and the default for your distro happens to be on, you might want to turn it off per interface by configuring it in the network interface configuration file.. This is distro-specific, but for example, in FC* you''d place a NETWORKING_IPV6=no in ifcfg-ethN, for instance. thanks, Nivedita _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
> We shouldn''t be doing all of those things (peth0) on the > guest OSs - we had gone to some pains to make sure the MAC > was unique across the system - have we regressed in that due > to the -xen kernel or some other reason?It''s the internal vifX.X interfaces that have the fe:ff:... addresses. There really is no business for any of these interfaces to be sourcing packets at all. Is there an option to the ''ip'' tool when bringing the interface up to prevent the ipv6 router solicitation? Ian _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
>> I''ve been looking into an issue were in the message file I see: >> Apr 28 11:43:10 kdell kernel: peth0: received packet with >> own address as source address >> >> Trying to match the time stamp in the message file to a >> packet trace captured by ethereal, I found that the offending >> packets are of the type >> ICMPv6 Multicast Listener Report Message v2, ICMPv6 Neighbor >> Solicitation, or ICMPv6 Router Solicitation packets. It >> looks like these packets are sent every time a network >> interface is brought up. In this case it is when peth0 is >> brought up from the network- bridge script since the MAC >> address is fe:ff:ff:ff:ff:ff. When a peth0 comes up, all >> other machines with a peth0 up and running will receive the >> packets and log the messages. >> >> Is this an issue of concern? > > It''s not of particular concern, but it would be nice to make themstop.> > Is it the ''ip link set dev X up'' line that causes the packet to besent? Yes, it is the ''ip link set ${pdev} up'' line.> Does anyone know how to make them stop? > > Thanks, > Ian_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Nivedita Singhvi
2006-May-01 15:26 UTC
Re: [Xen-devel] peth0 received packet on own address
Ian Pratt wrote:>>We shouldn''t be doing all of those things (peth0) on the >>guest OSs - we had gone to some pains to make sure the MAC >>was unique across the system - have we regressed in that due >>to the -xen kernel or some other reason? > > > It''s the internal vifX.X interfaces that have the fe:ff:... addresses. > There really is no business for any of these interfaces to be sourcing > packets at all. > > Is there an option to the ''ip'' tool when bringing the interface up to > prevent the ipv6 router solicitation?The ip tool mostly configures the settings on the card, and most of these are network protocol functions which merely get initiated once the interface comes up - they are mostly controlled by sysctl kernel parameters. So, for instance, setting /proc/sys/net/ipv6/conf/$interface/autoconf = 0 will turn off most of that. However, the /proc entry for the device is only created when we register the device, and the MLD and routing functions get initiated only when we designate the interface state as UP. Somewhere in between performing those two steps, we should turn off those sysctl vars. Will test that today.. thanks, Nivedita _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
> >> Trying to match the time stamp in the message file to a > packet trace > >> captured by ethereal, I found that the offending packets > are of the > >> type > >> ICMPv6 Multicast Listener Report Message v2, ICMPv6 Neighbor > >> Solicitation, or ICMPv6 Router Solicitation packets. It > looks like > >> these packets are sent every time a network interface is > brought up.> > Is it the ''ip link set dev X up'' line that causes the packet to be > sent? > > Yes, it is the ''ip link set ${pdev} up'' line.Does anyone know if there''s some parameter that can be given to the ''ip link set'' command to cause it not to send the ipv6 router solicitation? Ian _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel