Automatic IPv6 due to broadcast
cra at WPI.EDU
Mon Apr 23 08:25:25 CDT 2012
On Mon, Apr 23, 2012 at 12:24:53AM -0700, Owen DeLong wrote:
> On Apr 22, 2012, at 10:30 PM, Jimmy Hess wrote:
> > Particularly good L2 switches also have
> > DAI or "IP Source guard" IPv4 functions, which when properly
> > enabled, can foil certain L2 ARP and IPv4 source address spoofing
> > attacks, respectively.
> > e.g. Source IP address of packet does not match one of the DHCP leases
> > issued to that port -- then drop the packet.
> Meh... I can see many cases where that might be more of a bug than feature.
> Especially in environments where loops may be possible and the DHCP lease might
> have come over a different path than the port in question during some network event.
You're only supposed to use those features on the port directly
connected to the end-system, or to a few end-systems via an unmanaged
office switch that doesn't have redundant uplinks. I.e. edge ports.
More information about the NANOG