SIOCGIFFLAGS fails loopback interface

SIOCGIFFLAGS fails loopback interface

Post by Alexandros Karypidi » Thu, 15 Jul 2004 22:25:42



When I call ioctl() with SIOCGIFFLAGS for interface "lo" (loopback) it
fails.

strerror() says: No such device

The same code works for normal intefaces (ethX). Any ideas why this is so?

The reason I need this is to test whether the interface is multicast-capable
(flag IFF_MULTICAST).

 
 
 

SIOCGIFFLAGS fails loopback interface

Post by Floyd L. Davids » Fri, 16 Jul 2004 01:57:45



>When I call ioctl() with SIOCGIFFLAGS for interface "lo" (loopback) it
>fails.

>strerror() says: No such device

>The same code works for normal intefaces (ethX). Any ideas why this is so?

Your code has a bug.

Quote:>The reason I need this is to test whether the interface is multicast-capable
>(flag IFF_MULTICAST).

--
FloydL. Davidson           <http://web.newsguy.com/floyd_davidson>


 
 
 

1. Bringing up loopback interface: failed

Just out of curiosity? Can someone help me with this error during boot.  I
was assuming that I had removed the 127.0.0.1 part from my host file and
this may have been causing this, but I went back in and added it back.

It removed it automatically when I reconfigured my network card 3com 905BTX
to a static internal IP.  I then went back to DHCP.  My router has been
giving me trouble lately so I went static to see if that helped.  Ever
since then I get the error after changing back to DHCP.

Please Post And Reply.

Judgestone

2. kernel 2.4.0

3. YDL fails to set loopback interface :-(

4. Motif for Linux (cheaper than $149 ????)

5. ifconfig -a = ifconfig: ioctl (SIOCGIFFLAGS): no such interface

6. iMac and internet

7. x86 PPP - Need help - is_if_up: SIOCGIFFLAGS failed

8. token ring, Adapter/II, what is it?

9. "Bandwidth" of loopback interface?

10. Snoop - loopback interface?

11. Network Loopback Interface

12. volatile loopback interface

13. Performance advantage for loopback interface?