What is my Ethernet address?

[gregt]

In article <545 at siswat.UUCP> buck at siswat.UUCP (A. Lester Buck) writes:

   In article <432 at minya.UUCP>, jc at minya.UUCP (John Chambers) writes:
   > The only correct answer is one that gives the Ethernet address that is
   > on the card at this very instant, not one that "should" be there according
   > to some file or server which should (but may not) be correct.  I'm trying 
   > to determine whether those files and servers are correct; I can't very well 
   > ask them whether they're lying to me.  (Well, maybe I can; what does the
   > request packet look like? :-)

...

   register.  I am not really familiar with the Sun, but I thought I read at
   one time that Suns could load whatever Ethernet address they wanted from
   /etc/ethers onto the adapter.  

...

I not sure about that, but the way you read the address is by opening
/dev/nit, and hitting it with a SIOCGIFADDR ioctl - ala

	int f;
	struct ifreq if;
        if ((f = open("/dev/nit", 0)) < 0) {
                perror("open()");
                exit(1);
        }
        bzero(&if, sizeof(struct ifreq));  
        if.ifr_addr.sa_family = AF_NIT;
        strcpy(if.ifr_name, "ie0"); /* insert interface name here */     
        if (ioctl(f, NIOCBIND, &if) < 0) {
                perror("ioctl()");
                exit(2);
	}
	if (ioctl(f, SIOCGIFADDR, &if) < 0) {
                perror("ioctl()");
                exit(3);
        }
	
The address is filled in if.ifr_addr.sa_data

cheers,
greg tusar
(gregt at sdl.scs.com)


   -- 
   A. Lester Buck     buck at siswat.lonestar.org  ...!texbell!moray!siswat!buck

--
"Of all kinds of painting, figure painting is the most difficult;
then comes landscape painting, and next dogs and horses." - Ku K'ai-Chih :
gregt at sdl.scs.com // Gregory Tusar // Silicon Compiler Sys. // Warren, NJ