Make sure to explicitly configure the igp to export the default route by using the export statement. For instance if the igp is RIP, the configuration file should contain something like:
export proto rip {
proto static {
default;
};
};
If the igp or epg is a classless protocol (RIP 2, BGPv4), the protocol won't announce the class C unless explicitly configured to do so. The combined use of the aggregate and export statements should do the trick. See section 4.29.3 for a detailed example.
One problem is that, when using gcc to build gated, the C header files are not patched correctly. gcc uses it own headers in /usr/local/lib/gcc/<architecture>/<version>/include instead of the normal /usr/include, and those files do not get patched for multicast support. Therefore, gated won't consider any interface as multicast.
One solution is to copy the patched header files from /usr/include
to
/usr/local/lib/gcc/<architecture>/<version>/include.
That's means that your kernel does not support variables network mask (also refered as CIDR -- C.f. [RFC 1518]). For instance SunOS4.1 does not support them. As long as you use only classfull IP addresses (the old class A, B and C network, C.f. RCF 791), or RFC791-type subnetting, everything should be OK, just ignore the message. If you want to do CIDR, you need to get another OS, this problem is related to the kernel, not gated!
That's because you are trying to build gated with the ISODE SMUX support (i.e. you can use SNMP/SMUX to query gated). In order to to that you need to install the ISODE package first. (C.f. the INSTALL file for details). If you don't need SNMP you can just remove the 'isode_snmp' protocol from the list of protocols in your Config file (A few Config files distributed with gated have SNMP configured by default)