Match on IPv4 header options like source routing, record route, timestamp and router-alert. .TP .B "--ssrr" To match packets with the flag strict source routing. .TP .B "--lsrr" To match packets with the flag loose source routing. .TP .B "--no-srr" To match packets with no flag for source routing. .TP .B "\fR[\fB!\fR]\fB --rr" To match packets with the RR flag. .TP .B "\fR[\fB!\fR]\fB --ts" To match packets with the TS flag. .TP .B "\fR[\fB!\fR]\fB --ra" To match packets with the router-alert option. .TP .B "\fR[\fB!\fR]\fB --any-opt" To match a packet with at least one IP option, or no IP option at all if ! is chosen. .TP Examples: .TP $ iptables -A input -m ipv4options --rr -j DROP will drop packets with the record-route flag. .TP $ iptables -A input -m ipv4options --ts -j DROP will drop packets with the timestamp flag.