| arp.4 (35ef77a2eff0cdb9c8726a208843a84efdf5d019) | arp.4 (5bbdbbcda22167851c7431dc61ed9a6db75a17f9) |
|---|---|
| 1.\" Copyright (c) 1985, 1986, 1988, 1994 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. --- 14 unchanged lines hidden (view full) --- 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)arp4.4 6.5 (Berkeley) 4/18/94 29.\" $FreeBSD$ 30.\" | 1.\" Copyright (c) 1985, 1986, 1988, 1994 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. --- 14 unchanged lines hidden (view full) --- 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)arp4.4 6.5 (Berkeley) 4/18/94 29.\" $FreeBSD$ 30.\" |
| 31.Dd October 3, 2016 | 31.Dd October 7, 2016 |
| 32.Dt ARP 4 33.Os 34.Sh NAME 35.Nm arp 36.Nd Address Resolution Protocol 37.Sh SYNOPSIS 38.Cd "device ether" 39.Sh DESCRIPTION --- 76 unchanged lines hidden (view full) --- 116The ARP protocol implements a number of configurable variables in 117.Va net.link.ether.inet 118branch 119of the 120.Xr sysctl 3 121MIB. 122.Bl -tag -width "log_arp_permanent_modify" 123.It Va allow_multicast | 32.Dt ARP 4 33.Os 34.Sh NAME 35.Nm arp 36.Nd Address Resolution Protocol 37.Sh SYNOPSIS 38.Cd "device ether" 39.Sh DESCRIPTION --- 76 unchanged lines hidden (view full) --- 116The ARP protocol implements a number of configurable variables in 117.Va net.link.ether.inet 118branch 119of the 120.Xr sysctl 3 121MIB. 122.Bl -tag -width "log_arp_permanent_modify" 123.It Va allow_multicast |
| 124Should the kernel install ARP entries with multicast bit set in 125the hardware address. 126Installing such entries is RFC 1812 violation, but some prorietary 127load balancing techniques require routers on network to do so. | 124Install ARP entries with the multicast bit set in the hardware address. 125Installing such entries is an RFC 1812 violation, but some proprietary load 126balancing techniques require routers to do so. |
| 128Turned off by default. 129.It Va garp_rexmit_count | 127Turned off by default. 128.It Va garp_rexmit_count |
| 130Should the kernel retransmit gratuitous ARP (GARP) packets when an IPv4 address 131is added to an interface. | 129Retransmit gratuitous ARP (GARP) packets when an IPv4 address is added to an 130interface. |
| 132A GARP is always transmitted when an IPv4 address is added to an interface. | 131A GARP is always transmitted when an IPv4 address is added to an interface. |
| 133A non-zero value of this sysctl will cause the GARP packet to be retransmitted 134the stated number of times. | 132A non-zero value causes the GARP packet to be retransmitted the stated number 133of times. |
| 135The interval between retransmissions is doubled each time, so the 136retransmission intervals are: {1, 2, 4, 8, 16, ...} (seconds). 137The default value of zero means only the initial GARP is sent; no 138additional GARP packets are retransmitted. 139The maximum value is sixteen. 140.Pp | 134The interval between retransmissions is doubled each time, so the 135retransmission intervals are: {1, 2, 4, 8, 16, ...} (seconds). 136The default value of zero means only the initial GARP is sent; no 137additional GARP packets are retransmitted. 138The maximum value is sixteen. 139.Pp |
| 141Although a single GARP packet (the default behavior) is usually sufficient, in 142some circumstances, such as when a shared address is passed between cluster 143nodes, this single GARP may be dropped or lost. 144This can lead to neighbors on the network link working with a stale ARP cache 145and sending packets destined for that address to the node that previously owned 146the address, which may not respond. | 140The default behavior of a single GARP packet is usually sufficient. 141However, a single GARP might be dropped or lost in some circumstances. 142This is particularly harmful when a shared address is passed between cluster 143nodes. 144Neighbors on the network link might then work with a stale ARP cache and send 145packets destined for that address to the node that previously owned the 146address, which might not respond. |
| 147.It Va log_arp_movements | 147.It Va log_arp_movements |
| 148Should the kernel log movements of IP addresses from one hardware 149address to an other. | 148Log movements of IP addresses from one hardware address to another. |
| 150See 151.Sx DIAGNOSTICS 152below. 153Turned on by default. 154.It Va log_arp_permanent_modify | 149See 150.Sx DIAGNOSTICS 151below. 152Turned on by default. 153.It Va log_arp_permanent_modify |
| 155Should the kernel log attempts of remote host on network to modify a 156permanent ARP entry. | 154Log attempts by a remote host to modify a permanent ARP entry. |
| 157See 158.Sx DIAGNOSTICS 159below. 160Turned on by default. 161.It Va log_arp_wrong_iface | 155See 156.Sx DIAGNOSTICS 157below. 158Turned on by default. 159.It Va log_arp_wrong_iface |
| 162Should the kernel log attempts to insert an ARP entry on an interface 163when the IP network the address belongs to is connected to an other 164interface. | 160Log attempts to insert an ARP entry on an interface when the IP network to 161which the address belongs is connected to another interface. |
| 165See 166.Sx DIAGNOSTICS 167below. 168Turned on by default. 169.It Va max_log_per_second | 162See 163.Sx DIAGNOSTICS 164below. 165Turned on by default. 166.It Va max_log_per_second |
| 170Limit number of remotely triggered logging events to a configured value 171per second. | 167Limit the number of remotely triggered logging events to a configured value per 168second. |
| 172Default is 1 log message per second. 173.It Va max_age 174How long an ARP entry is held in the cache until it needs to be refreshed. 175Default is 1200 seconds. 176.It Va maxhold | 169Default is 1 log message per second. 170.It Va max_age 171How long an ARP entry is held in the cache until it needs to be refreshed. 172Default is 1200 seconds. 173.It Va maxhold |
| 177How many packets hold in the per-entry output queue while the entry | 174How many packets to hold in the per-entry output queue while the entry |
| 178is being resolved. 179Default is one packet. 180.It Va maxtries | 175is being resolved. 176Default is one packet. 177.It Va maxtries |
| 181Number of retransmits before host is considered down and error is returned. | 178Number of retransmits before a host is considered down and an error is 179returned. |
| 182Default is 5 tries. 183.It Va proxyall | 180Default is 5 tries. 181.It Va proxyall |
| 184Enables ARP proxying for all hosts on net. | 182Enables ARP proxying. |
| 185Turned off by default. 186.It Va wait 187Lifetime of an incomplete ARP entry. 188Default is 20 seconds. 189.El 190.Sh DIAGNOSTICS 191.Bl -diag 192.It "arp: %x:%x:%x:%x:%x:%x is using my IP address %d.%d.%d.%d on %s!" --- 61 unchanged lines hidden --- | 183Turned off by default. 184.It Va wait 185Lifetime of an incomplete ARP entry. 186Default is 20 seconds. 187.El 188.Sh DIAGNOSTICS 189.Bl -diag 190.It "arp: %x:%x:%x:%x:%x:%x is using my IP address %d.%d.%d.%d on %s!" --- 61 unchanged lines hidden --- |