<tt>libvir-list-bounces@redhat.com wrote on 08/13/2010 03:11:25 PM: </tt> <tt>> > On 08/13/2010 12:38 PM, Stefan Berger wrote: > > When sniffing the network traffic, discard class D and E IP addresses > > when sniffing traffic. This was a reason why filters were not correctly > > rebuilt on VMs on the local 192.* network when libvirt was restarted and > > those VMs did not use a DHCP request to get its IP address. > > > > Signed-off-by: Stefan Berger <stefanb@us.ibm.com> > > > > --- > > src/nwfilter/nwfilter_learnipaddr.c | 7 +++++-- > > 1 file changed, 5 insertions(+), 2 deletions(-) > > > > Index: libvirt-acl/src/nwfilter/nwfilter_learnipaddr.c > > =================================================================== > > --- libvirt-acl.orig/src/nwfilter/nwfilter_learnipaddr.c > > +++ libvirt-acl/src/nwfilter/nwfilter_learnipaddr.c > > @@ -546,9 +546,12 @@ learnIPAddressThread(void *arg) > > struct iphdr *iphdr = (struct iphdr*)(packet + > > ethHdrSize); > > vmaddr = iphdr->saddr; > > - // skip eth. bcast and mcast addresses, > > + // skip eth. bcast and mcast addresses (224.0.0.0 - > > + // 239.255.255.255), class E (255.*) > > // and zero address in DHCP Requests > > - if ((ntohl(vmaddr) & 0xc0000000) || vmaddr == 0) { > > + if ( (ntohl(vmaddr) & 0xe0000000) == 0xe0000000 || > > This line's fine for 224-239.*, but... > > > + (ntohl(vmaddr) & 0xf0000000) == 0xf0000000 || > > shouldn't this be (ntohl(vmaddr) & 0xff000000) == 0xff000000, so that > you are not excluding 254.*? > </tt> <tt>Looking at Wikipedia for this</tt> <a href=http://en.wikipedia.org/wiki/Classful_network><tt>http://en.wikipedia.org/wiki/Classful_network</tt></a> <tt>Class D addresses have highest bits with pattern 1110 0000 -> 0xe0</tt> <tt>Class E addresses have highest bits with pattern 1111 0000 -> 0xf0</tt> <tt>I think my masks are fine and the masking with 0xf0 00 00 00 should also include 254.* = 0xfe.* .</tt> <tt> Stefan</tt>