I am using 'if_nameindex()' to get the list of network interface names. Apparently, on RHEL 4, this does not return the network interfaces having secondary ip address (ie eth0:1, eth1:1 ….). However on RHEL3, it works fine. On RHEL3, it returns lo, eth0, eth0:1, eth1…

Not sure why the behavior is different on RHEL4. Does anybody have any clue ?

here is the code
-------------------------------------------------
// open a socket for ioctls
if ((fd = socket(PF_PACKET,
SOCK_PACKET,
htons(ETH_P_ALL))) == -1)
{
// print failed
}

// get list of network interface names
if ((pIFList = if_nameindex()) == NULL)
{
close(fd);
// print failed
}
------------------------------------------------------

Try with:
1- getifaddrs(3) if available
2- pcap_findalldevs() - See pcap(3)
3- The older (more portable) SIOCGIFCONF ioctl() - See netdevice(7)