1 This matches the routing realm. Routing realms are used in complex routing
2 setups involving dynamic routing protocols like BGP.
4 [\fB!\fP] \fB--realm\fP \fIvalue\fP[\fB/\fP\fImask\fP]
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