Q1. Is there a definitive way to tell if a particular kernel supports IP aliasing? Background ---------- I'm writing a tutorial on DNS that involves IP aliasing. Most of the pre-packaged Debian kernels do support it, but kernel-image-2.2.20-idepci 2.2.20-5 doesn't -- when you ifconfig eth0:1 10.1.2.3 it gives errors (on a laptop): SIOCSIFADDR: No such device SIOCSIFFLAGS: No such device By downloading the Debian files you can eventually see, in the kernel config file from the kernel-image tar file, that # CONFIG_IP_ALIAS is not set But this is more than a newcomer to Linux could reasonably do; hence, is there a definitive way for a newbie to see if error messages are due to a kernel limitation rather than a mistake on their part? A related question: Q2. In 2.2.x kernels, aliasing was compiled if CONFIG_IP_ALIAS is set. What controls this in new kernels where CONFIG_IP_ALIAS is no longer an option? (Or from some kernel version onwards has aliasing always been enabled?) Thanks, Niall - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html