diff options
| -rw-r--r-- | sys/netinet/if_ether.c | 8 | ||||
| -rw-r--r-- | usr.sbin/arp/arp.4 | 11 |
2 files changed, 16 insertions, 3 deletions
diff --git a/sys/netinet/if_ether.c b/sys/netinet/if_ether.c index 8e2daeb..52d7db2 100644 --- a/sys/netinet/if_ether.c +++ b/sys/netinet/if_ether.c @@ -496,6 +496,7 @@ arpintr(struct mbuf *m) static int log_arp_wrong_iface = 1; static int log_arp_movements = 1; static int log_arp_permanent_modify = 1; +static int allow_multicast = 0; SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_wrong_iface, CTLFLAG_RW, &log_arp_wrong_iface, 0, @@ -506,7 +507,8 @@ SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_movements, CTLFLAG_RW, SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_permanent_modify, CTLFLAG_RW, &log_arp_permanent_modify, 0, "log arp replies from MACs different than the one in the permanent arp entry"); - +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, allow_multicast, CTLFLAG_RW, + &allow_multicast, 0, "accept multicast addresses"); static void in_arpinput(struct mbuf *m) @@ -551,8 +553,8 @@ in_arpinput(struct mbuf *m) return; } - if (ETHER_IS_MULTICAST(ar_sha(ah))) { - log(LOG_NOTICE, "in_arp: %*D is multicast\n", + if (allow_multicast == 0 && ETHER_IS_MULTICAST(ar_sha(ah))) { + log(LOG_NOTICE, "arp: %*D is multicast\n", ifp->if_addrlen, (u_char *)ar_sha(ah), ":"); return; } diff --git a/usr.sbin/arp/arp.4 b/usr.sbin/arp/arp.4 index 980ca71..0ff0f2c 100644 --- a/usr.sbin/arp/arp.4 +++ b/usr.sbin/arp/arp.4 @@ -120,6 +120,12 @@ of the .Xr sysctl 3 MIB. .Bl -tag -width "log_arp_permanent_modify" +.It Va allow_multicast +Should the kernel install ARP entries with multicast bit set in +the hardware address. +Installing such entries is RFC 1812 violation, but some prorietary +load balancing techniques require routers on network to do so. +Turned off by default. .It Va log_arp_movements Should the kernel log movements of IP addresses from one hardware address to an other. @@ -203,6 +209,11 @@ entry in the local ARP table. This error will only be logged if the sysctl .Va net.link.ether.inet.log_arp_permanent_modify is set to 1, which is the system's default behaviour. +.It "arp: %x:%x:%x:%x:%x:%x is multicast" +Kernel refused to install an entry with multicast hardware address. +If you really want such addresses being installed, set the sysctl +.Va net.link.ether.inet.allow_multicast +to a positive value. .El .Sh SEE ALSO .Xr inet 4 , |
