Default Maximum Transfer Unit
        Default: 1280 (IPv6 required minimum)
 
+router_probe_interval - INTEGER
+       Minimum interval (in seconds) between Router Probing described
+       in RFC4191.
+
+       Default: 60
+
 router_solicitation_delay - INTEGER
        Number of seconds to wait after interface is brought up
        before sending Router Solicitations.
 
        __s32           accept_ra_pinfo;
 #ifdef CONFIG_IPV6_ROUTER_PREF
        __s32           accept_ra_rtr_pref;
+       __s32           rtr_probe_interval;
 #endif
        void            *sysctl;
 };
        DEVCONF_ACCEPT_RA_DEFRTR,
        DEVCONF_ACCEPT_RA_PINFO,
        DEVCONF_ACCEPT_RA_RTR_PREF,
+       DEVCONF_RTR_PROBE_INTERVAL,
        DEVCONF_MAX
 };
 
 
        NET_IPV6_ACCEPT_RA_DEFRTR=18,
        NET_IPV6_ACCEPT_RA_PINFO=19,
        NET_IPV6_ACCEPT_RA_RTR_PREF=20,
+       NET_IPV6_RTR_PROBE_INTERVAL=21,
        __NET_IPV6_MAX
 };
 
 
        .accept_ra_pinfo        = 1,
 #ifdef CONFIG_IPV6_ROUTER_PREF
        .accept_ra_rtr_pref     = 1,
+       .rtr_probe_interval     = 60 * HZ,
 #endif
 };
 
        .accept_ra_pinfo        = 1,
 #ifdef CONFIG_IPV6_ROUTER_PREF
        .accept_ra_rtr_pref     = 1,
+       .rtr_probe_interval     = 60 * HZ,
 #endif
 };
 
        array[DEVCONF_ACCEPT_RA_PINFO] = cnf->accept_ra_pinfo;
 #ifdef CONFIG_IPV6_ROUTER_PREF
        array[DEVCONF_ACCEPT_RA_RTR_PREF] = cnf->accept_ra_rtr_pref;
+       array[DEVCONF_RTR_PROBE_INTERVAL] = cnf->rtr_probe_interval;
 #endif
 }
 
                        .mode           =       0644,
                        .proc_handler   =       &proc_dointvec,
                },
+               {
+                       .ctl_name       =       NET_IPV6_RTR_PROBE_INTERVAL,
+                       .procname       =       "router_probe_interval",
+                       .data           =       &ipv6_devconf.rtr_probe_interval,
+                       .maxlen         =       sizeof(int),
+                       .mode           =       0644,
+                       .proc_handler   =       &proc_dointvec_jiffies,
+                       .strategy       =       &sysctl_jiffies,
+               },
 #endif
                {
                        .ctl_name       =       0,      /* sentinel */
 
                return;
        read_lock_bh(&neigh->lock);
        if (!(neigh->nud_state & NUD_VALID) &&
-           time_after(jiffies, neigh->updated + 60 * HZ)) {
+           time_after(jiffies, neigh->updated + rt->rt6i_idev->cnf.rtr_probe_interval)) {
                struct in6_addr mcaddr;
                struct in6_addr *target;