1 This matches the routing realm. Routing realms are used in complex routing 2 setups involving dynamic routing protocols like BGP. 3 .TP 4 .BI "--realm " "[!] " "value[/mask]" 5 Matches a given realm number (and optionally mask). If not a number, value 6 can be a named realm from /etc/iproute2/rt_realms (mask can not be used in 7 that case). 8