Hi All,

I am writing a program that tests the health of a NIC card. I am
creating a NDD socket (Data Link Access) which I will use to send ICMP
ECHO packets to a given host. This means that my application has to
build the entire packet and I have to create and add the IP/IPv6, ICMP/
6, and MAC headers in my application. I got things to work for IP, but
I am stuck with IPv6:

1) How do I find the MAC address for an IPv6 remote host? For IP, I
use the SIOCGARP ioctl and get the MAC adress from the ARP cache. But
IPv6 does not use ARP. there is something called neighbor discovery
for IPv6, but I could not find any programatic interface to use it ..

2) How do I do a broadcast ping in IPv6? In v4, I just put the
broadcast address in the destination addr fiend of the IP header and
things worked, but what do I do for v6?

Thanks in advance for your .

Jigs

In article <1176233989.807517.266810@v33g2000cwv.googlegroups .com>,
"Jigs" <jigar.jigar@gmail.com> wrote:

> 2) How do I do a broadcast ping in IPv6? In v4, I just put the
> broadcast address in the destination addr fiend of the IP header and
> things worked, but what do I do for v6?

IPv6 doesn't have broadcast, but it has an elaborate multicast
addressing scheme. The analogue to local broadcasting is sending to the
all-nodes multicast address with link-local scope, FF02::1. I don't
think there's any equivalent to directed broadcasts; however, they're
rarely used because they're usually filtered (because the most common
use of them has been to implement DoS attacks).

--
Barry Margolin, barmar@alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***
*** PLEASE don't copy me on replies, I'll read them in the group ***

"Jigs" <jigar.jigar@gmail.com> writes:
> 1) How do I find the MAC address for an IPv6 remote host? For IP, I
> use the SIOCGARP ioctl and get the MAC adress from the ARP cache. But
> IPv6 does not use ARP. there is something called neighbor discovery
> for IPv6, but I could not find any programatic interface to use it ..

SIOCLIFGETND on Solaris.

You could just forge up the Neighbor Discovery messages yourself.

(Is "ndd socket" an AIX thing? Something else?)

--
James Carlson, Solaris Networking <james.d.carlson@sun.com>
Sun Microsystems / 1 Network Drive 71.232W Vox +1 781 442 2084
MS UBUR02-212 / Burlington MA 01803-2757 42.496N Fax +1 781 442 1677

On Apr 11, 8:41 am, James Carlson <james.d.carl...@sun.com> wrote:
> "Jigs" <jigar.ji...@gmail.com> writes:
> > 1) How do I find the MAC address for an IPv6 remote host? For IP, I
> > use the SIOCGARP ioctl and get the MAC adress from the ARP cache. But
> > IPv6 does not use ARP. there is something called neighbor discovery
> > for IPv6, but I could not find any programatic interface to use it ..
>
> SIOCLIFGETND on Solaris.
>
> You could just forge up the Neighbor Discovery messages yourself.
>
> (Is "ndd socket" an AIX thing? Something else?)
>
> --
> James Carlson, Solaris Networking <james.d.carl...@sun.com>
> Sun Microsystems / 1 Network Drive 71.232W Vox +1 781 442 2084
> MS UBUR02-212 / Burlington MA 01803-2757 42.496N Fax +1 781 442 1677


Yeah, NDD sockets is on AIX. Using these sockets, you can write your
own packets to the Data Link Layer (I think DLPI is equilvalent on
solaris). Can you please explain how to build the Neighbor Discovery
messages?

"Jigs" <jigar.jigar@gmail.com> writes:
> Yeah, NDD sockets is on AIX. Using these sockets, you can write your
> own packets to the Data Link Layer (I think DLPI is equilvalent on
> solaris). Can you please explain how to build the Neighbor Discovery
> messages?

You'll want to read through RFCs 2461 for ND, 2460 for IPv6, and 2464
for IPv6 over Ethernet. It's pretty straightforward.

--
James Carlson, Solaris Networking <james.d.carlson@sun.com>
Sun Microsystems / 1 Network Drive 71.232W Vox +1 781 442 2084
MS UBUR02-212 / Burlington MA 01803-2757 42.496N Fax +1 781 442 1677