taglinefilesource code
RTF_HOST547drivers/net/sunlance.cserver_route.rt_flags=RTF_HOST|RTF_UP;
RTF_HOST590fs/nfs/nfsroot.croute.rt_flags = RTF_HOST | RTF_UP;
RTF_HOST491net/appletalk/ddp.cif(!(r->flags&RTF_HOST) || r->target.s_node==target->s_node)
RTF_HOST567net/appletalk/ddp.cif(!(rt->flags&RTF_HOST))
RTF_HOST768net/appletalk/ddp.crtdef.rt_flags|=RTF_HOST;
RTF_HOST528net/ipv4/route.cif (flags & RTF_HOST) 
RTF_HOST1125net/ipv4/route.crt->rt_flags = RTF_DYNAMIC | RTF_MODIFIED | RTF_HOST | RTF_GATEWAY | RTF_UP;
RTF_HOST1553net/ipv4/route.crth->rt_flags   = fi->fib_flags | RTF_HOST;
RTF_HOST1678net/ipv4/route.cif (flags & RTF_HOST)