Dear Rusty: I am an graduate student of China.Recently,I want to insert an module to Netfilter,so I can get the information of the cleint and master the client.But when i do it ,I find an error occured. First I make an function exam,then I add the sentence like the underline: static struct nf_hook_ops test{{NULL,NULL},exam,PF_INET,NF_IP_PRE_ROUTING,NF_IP_PRI_FILTER} add the function init_module(),cleanup_module(),compiled it,the error is: "variable 'test' has initializer but incomplete type" "extra brace group at end of initializer" Even I copy the /usr/src/net/ipv4/netfilter/ip_nat_standalone.c and make it,the error occured as before. I am looking forward to haering from you at your point you have.this is important to me. Sincerely yours zhongfuyao charly [EMAIL PROTECTED]