<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML ><HEAD ><TITLE >Entries in /proc/sys/net/ipv6/</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK REL="HOME" TITLE="Linux IPv6 HOWTO (en)" HREF="index.html"><LINK REL="UP" TITLE="Kernel settings in /proc-filesystem" HREF="chapter-kernel-settings.html"><LINK REL="PREVIOUS" TITLE="How to access the /proc-filesystem" HREF="x1371.html"><LINK REL="NEXT" TITLE="IPv6-related entries in /proc/sys/net/ipv4/" HREF="proc-sys-net-ipv4..html"></HEAD ><BODY CLASS="SECT1" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#840084" ALINK="#0000FF" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >Linux IPv6 HOWTO (en)</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="x1371.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" >Chapter 11. Kernel settings in /proc-filesystem</TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="proc-sys-net-ipv4..html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="SECT1" ><H1 CLASS="SECT1" ><A NAME="PROC-SYS-NET-IPV6." ></A >11.2. Entries in /proc/sys/net/ipv6/</H1 ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A NAME="AEN1431" ></A >11.2.1. conf/default/*</H2 ><P >Change the interface-specific default settings.</P ></DIV ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A NAME="AEN1434" ></A >11.2.2. conf/all/*</H2 ><P >Change all the interface-specific settings.</P ><P >Exception: “conf/all/forwarding” has a different meaning here</P ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1438" ></A >11.2.2.1. conf/all/forwarding</H3 ><P ></P ><UL ><LI ><P >Type: BOOLEAN</P ></LI ></UL ><P >This enables global IPv6 forwarding between all interfaces.</P ><P >In IPv6 you can't control forwarding per device, forwarding control has to be done using IPv6-netfilter (controlled with ip6tables) rulesets and specify input and output devices (see <A HREF="firewalling-netfilter6..html" >Firewalling/Netfilter6</A > for more). This is different to IPv4, where you are able to control forwarding per device (decision is made on interface where packet came in).</P ><P >This also sets all interfaces' Host/Router setting 'forwarding' to the specified value. See below for details. This referred to as global forwarding.</P ><P >If this value is 0, no IPv6 forwarding is enabled, packets never leave another interface, neither physical nor logical like e.g. tunnels.</P ></DIV ></DIV ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A NAME="AEN1448" ></A >11.2.3. conf/interface/*</H2 ><P >Change special settings per interface.</P ><P >The functional behaviour for certain settings is different depending on whether local forwarding is enabled or not.</P ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1452" ></A >11.2.3.1. accept_ra</H3 ><P ></P ><UL ><LI ><P >Type: BOOLEAN</P ></LI ><LI ><P >Functional default: enabled if local forwarding is disabled. disabled if local forwarding is enabled.</P ></LI ></UL ><P >Accept Router Advertisements, and autoconfigure this interface with received data.</P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1460" ></A >11.2.3.2. accept_redirects</H3 ><P ></P ><UL ><LI ><P >Type: BOOLEAN</P ></LI ><LI ><P >Functional default: enabled if local forwarding is disabled. disabled if local forwarding is enabled.</P ></LI ></UL ><P >Accept Redirects sent by an IPv6 router.</P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1468" ></A >11.2.3.3. autoconf</H3 ><P ></P ><UL ><LI ><P >Type: BOOLEAN</P ></LI ><LI ><P >Functional default: enabled if accept_ra_pinfo is enabled. disabled if accept_ra_pinfo is disabled.</P ></LI ></UL ><P >Autoconfigure addresses using prefix information from router advertisements.</P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1476" ></A >11.2.3.4. dad_transmits</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 1</P ></LI ></UL ><P >The amount of Duplicate Address Detection probes to send.</P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1484" ></A >11.2.3.5. forwarding</H3 ><P ></P ><UL ><LI ><P >Type: BOOLEAN</P ></LI ><LI ><P >Default: FALSE if global forwarding is disabled (default), otherwise TRUE</P ></LI ></UL ><P >Configure interface-specific Host/Router behaviour.</P ><P >Note: It is recommended to have the same setting on all interfaces; mixed router/host scenarios are rather uncommon.</P ><P ></P ><UL ><LI ><P >Value FALSE: By default, Host behaviour is assumed. This means:</P ></LI ></UL ><P ></P ><OL TYPE="1" ><LI ><P >IsRouter flag is not set in Neighbour Advertisements.</P ></LI ><LI ><P >Router Solicitations are being sent when necessary.</P ></LI ><LI ><P >If accept_ra is TRUE (default), accept Router Advertisements (and do autoconfiguration).</P ></LI ><LI ><P >If accept_redirects is TRUE (default), accept Redirects.</P ></LI ></OL ><P ></P ><UL ><LI ><P >Value TRUE: If local forwarding is enabled, Router behaviour is assumed. This means exactly the reverse from the above:</P ></LI ></UL ><P ></P ><OL TYPE="1" ><LI ><P >IsRouter flag is set in Neighbour Advertisements.</P ></LI ><LI ><P >Router Solicitations are not sent.</P ></LI ><LI ><P >Router Advertisements are ignored.</P ></LI ><LI ><P >Redirects are ignored.</P ></LI ></OL ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1517" ></A >11.2.3.6. hop_limit</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 64</P ></LI ></UL ><P >Default Hop Limit to set.</P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1525" ></A >11.2.3.7. mtu</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 1280 (IPv6 required minimum)</P ></LI ></UL ><P >Default Maximum Transfer Unit</P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1533" ></A >11.2.3.8. router_solicitation_delay</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 1</P ></LI ></UL ><P >Number of seconds to wait after interface is brought up before sending Router Solicitations.</P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1541" ></A >11.2.3.9. router_solicitation_interval</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 4</P ></LI ></UL ><P >Number of seconds to wait between Router Solicitations. </P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1549" ></A >11.2.3.10. router_solicitations</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 3</P ></LI ></UL ><P >Number of Router Solicitations to send until assuming no routers are present.</P ></DIV ></DIV ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A NAME="AEN1557" ></A >11.2.4. neigh/default/*</H2 ><P >Change default settings for neighbor detection and some special global interval and threshold values:</P ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1560" ></A >11.2.4.1. gc_thresh1</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 128</P ></LI ></UL ><P >More to be filled.</P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1568" ></A >11.2.4.2. gc_thresh2</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 512</P ></LI ></UL ><P >More to be filled.</P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1576" ></A >11.2.4.3. gc_thresh3</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 1024</P ></LI ></UL ><P >Tuning parameter for neighbour table size.</P ><P >Increase this value if you have a lot of interfaces and problem with routes start to act mysteriously and fail. Or if a running <A HREF="http://www.zebra.org/" TARGET="_top" >Zebra (routing daemon)</A > reports:</P ><TABLE BORDER="1" BGCOLOR="#E0E0E0" WIDTH="100%" ><TR ><TD ><FONT COLOR="#000000" ><PRE CLASS="SCREEN" >ZEBRA: netlink-listen error: No buffer space available, type=RTM_NEWROUTE(24), seq=426, pid=0</PRE ></FONT ></TD ></TR ></TABLE ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1587" ></A >11.2.4.4. gc_interval</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 30</P ></LI ></UL ><P >More to be filled.</P ></DIV ></DIV ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A NAME="AEN1595" ></A >11.2.5. neigh/interface/*</H2 ><P >Change special settings per interface for neighbor detection.</P ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1598" ></A >11.2.5.1. anycast_delay</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 100</P ></LI ></UL ><P >More to be filled.</P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1606" ></A >11.2.5.2. gc_stale_time</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 60</P ></LI ></UL ><P >More to be filled.</P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1614" ></A >11.2.5.3. proxy_qlen</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 64</P ></LI ></UL ><P >More to be filled.</P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1622" ></A >11.2.5.4. unres_qlen</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 3</P ></LI ></UL ><P >More to be filled.</P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1630" ></A >11.2.5.5. app_solicit</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 0</P ></LI ></UL ><P >More to be filled.</P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1638" ></A >11.2.5.6. locktime</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 0</P ></LI ></UL ><P >More to be filled.</P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1646" ></A >11.2.5.7. retrans_time</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 100</P ></LI ></UL ><P >More to be filled.</P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1654" ></A >11.2.5.8. base_reachable_time</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 30</P ></LI ></UL ><P >More to be filled.</P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1662" ></A >11.2.5.9. mcast_solicit</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 3</P ></LI ></UL ><P >More to be filled.</P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1670" ></A >11.2.5.10. ucast_solicit</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 3</P ></LI ></UL ><P >More to be filled</P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1678" ></A >11.2.5.11. delay_first_probe_time</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 5</P ></LI ></UL ><P >More to be filled.</P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1686" ></A >11.2.5.12. proxy_delay</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 80</P ></LI ></UL ><P >More to be filled.</P ></DIV ></DIV ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A NAME="AEN1694" ></A >11.2.6. route/*</H2 ><P >Change global settings for routing.</P ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1697" ></A >11.2.6.1. flush</H3 ><P >Removed in newer kernel releases - more to be filled.</P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1700" ></A >11.2.6.2. gc_interval</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 30</P ></LI ></UL ><P >More to be filled.</P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1708" ></A >11.2.6.3. gc_thresh</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 1024</P ></LI ></UL ><P >More to be filled.</P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1716" ></A >11.2.6.4. mtu_expires</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 600</P ></LI ></UL ><P >More to be filled.</P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1724" ></A >11.2.6.5. gc_elasticity</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 0</P ></LI ></UL ><P >More to be filled.</P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1732" ></A >11.2.6.6. gc_min_interval</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 5</P ></LI ></UL ><P >More to be filled.</P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1740" ></A >11.2.6.7. gc_timeout</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 60</P ></LI ></UL ><P >More to be filled.</P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1748" ></A >11.2.6.8. min_adv_mss</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 12</P ></LI ></UL ><P >More to be filled.</P ></DIV ><DIV CLASS="SECT3" ><H3 CLASS="SECT3" ><A NAME="AEN1756" ></A >11.2.6.9. max_size</H3 ><P ></P ><UL ><LI ><P >Type: INTEGER</P ></LI ><LI ><P >Default: 4096</P ></LI ></UL ><P >More to be filled.</P ></DIV ></DIV ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="x1371.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="proc-sys-net-ipv4..html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >How to access the /proc-filesystem</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="chapter-kernel-settings.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >IPv6-related entries in /proc/sys/net/ipv4/</TD ></TR ></TABLE ></DIV ></BODY ></HTML >
