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This is the Chinese FAQ. Some part have not finish yet.
1999-01-31 00:20:34 +01:00
<!-- $Id: network.sgml,v 1.1.1.1 1999-01-30 23:20:34 vanilla Exp $ -->
<!-- The FreeBSD Documentation Project -->
<!-- Translate into Chinese by wing@cc.nsysu.edu.tw -->
<!-- English Version: 1.18 -->
<sect>
<heading>Networking<label id="networking"></heading>
<sect1>
<heading><3E><><EFBFBD><EFBFBD><EFBFBD>Ө<EFBFBD><D3A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD>䦳<EFBFBD><E4A6B3><EFBFBD>L<EFBFBD>Ϻж}<7D><> (diskless booting) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>?</heading>
<p><3E>L<EFBFBD>Ϻж}<7D><><EFBFBD>N<EFBFBD>O<EFBFBD><4F> FreeBSD <20>D<EFBFBD><44><EFBFBD>q<EFBFBD><71><EFBFBD><EFBFBD><EFBFBD>W<EFBFBD>}<7D><>,<2C>åB<C3A5>q<EFBFBD><71><EFBFBD><EFBFBD><EFBFBD>W<EFBFBD><57> server <20>WŪ<57><C5AA>
<20><><EFBFBD>L<EFBFBD><4C><EFBFBD>n<EFBFBD><6E><EFBFBD>ɮ<EFBFBD>,<2C>ӫD<D3AB>ѥD<D1A5><44><EFBFBD><EFBFBD><EFBFBD>w<EFBFBD>ФW<D0A4><57><EFBFBD>o<EFBFBD>o<EFBFBD><6F><EFBFBD>ɮסC <20>ԲӪ<D4B2><D3AA><EFBFBD><EFBFBD>ƥi<C6A5>H<EFBFBD>Ѧ<EFBFBD>
its hard disk. For full details, please read
<url url="../handbook/diskless.html"
name="FreeBSD <20><><EFBFBD>U<EFBFBD><55><EFBFBD>L<EFBFBD>Ϻж}<7D><><EFBFBD>g">
<sect1>
<heading>
FreeBSD <20><><EFBFBD>D<EFBFBD><44><EFBFBD>i<EFBFBD>H<EFBFBD><48><EFBFBD>@<40>Y<EFBFBD>Ӻ<EFBFBD><D3BA><EFBFBD><EFBFBD>W<EFBFBD><57><EFBFBD><EFBFBD><EFBFBD>Ѿ<EFBFBD> (router) <20><> ?
</heading>
<p><3E>ѩ<EFBFBD><D1A9><EFBFBD><EFBFBD>ں<EFBFBD><DABA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>зǤƩM<C6A9>{<7B><><EFBFBD>]<5D>p<EFBFBD><70><EFBFBD>R<EFBFBD><52><EFBFBD>g<EFBFBD>礧<EFBFBD><E7A4A7>,<2C>ڭ<EFBFBD>
<20><><EFBFBD><EFBFBD><EFBFBD>b FreeBSD <20>t<EFBFBD>Τ<EFBFBD><CEA4>ثʥ]<5D><><EFBFBD><EFBFBD> (packet fowarding) <20><><EFBFBD>\<5C><><EFBFBD>C<EFBFBD>A<EFBFBD>i<EFBFBD>H
<20>N<EFBFBD>o<EFBFBD>ӥ\<5C>ॴ<EFBFBD>},<2C>u<EFBFBD>n<EFBFBD>N<EFBFBD>o<EFBFBD><6F><EFBFBD>ܼƳ]<5D>w<EFBFBD><77>
<tt/YES/ <20>b <htmlurl url="http://www.freebsd.org/cgi/man.cgi?rc.conf"
name="rc.conf"><3E>o<EFBFBD><6F><EFBFBD>ɮפ<C9AE>
<verb>
gateway_enable=YES # Set to YES if this host will be a gateway
</verb>
<p><3E>o<EFBFBD>ӿﶵ<D3BF>|<7C>N <htmlurl
url="http://www.freebsd.org/cgi/man.cgi?sysctl" name="sysctl"> <20>ܼƳ]<5D>w
<tt/net.inet.ip.forwarding/ <20><> <tt/1/.
<p><3E>b<EFBFBD>j<EFBFBD><6A><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>p<EFBFBD>U, <20>A<EFBFBD>٥<EFBFBD><D9A5><EFBFBD><EFBFBD>A<EFBFBD>]<5D>@<40>ӳB<D3B3>z routing <20><><EFBFBD>{<7B><>,<2C>i<EFBFBD>D<EFBFBD><44><EFBFBD><EFBFBD><EFBFBD>W<EFBFBD><57><EFBFBD><EFBFBD><EFBFBD>L
<20>D<EFBFBD><44><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>A<EFBFBD><41> router <20>]<5D>w<EFBFBD><77><EFBFBD><EFBFBD><EFBFBD><EFBFBD>; FreeBSD
<20>X<EFBFBD>t<EFBFBD>ɫK<C9AB><4B><EFBFBD><EFBFBD><EFBFBD>@<40>ӼзǪ<D0B7> BSD routing <20>{<7B><>
<htmlurl url="http://www.freebsd.org/cgi/man.cgi?routed"
name="routed">, <20>p<EFBFBD>G<EFBFBD>A<EFBFBD><41><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>]<5D>w<EFBFBD>󬰽<EFBFBD><F3ACB0BD><EFBFBD>,<2C>A<EFBFBD>i<EFBFBD>H<EFBFBD>ոլ<D5B8>
<em/GaTeD/ (<28>i<EFBFBD>H<EFBFBD>H FTP <20>覡<EFBFBD><E8A6A1> <tt/ftp.gated.Merit.EDU/ <20>U<EFBFBD><55>)
<20>o<EFBFBD>ӵ{<7B><><EFBFBD><EFBFBD> 3_5Alpha7 <20><><EFBFBD>䴩 FreeBSD .
<p><3E>ڭ̦<DAAD><CCA6><EFBFBD><EFBFBD>n<EFBFBD>i<EFBFBD>D<EFBFBD>A,<2C>N<EFBFBD><4E><EFBFBD>O FreeBSD <20>H<EFBFBD>o<EFBFBD>ؤ覡<D8A4>]<5D>w<EFBFBD><77><EFBFBD><EFBFBD>
, <20><><EFBFBD>٬O<D9AC>L<EFBFBD>k<EFBFBD><6B><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Internet <20><> router <20><><EFBFBD>зǩw<C7A9>q
;<3B><><EFBFBD>L, <20>N<EFBFBD><4E><EFBFBD>`<60>ϥΦӨ<CEA6><D3A8><EFBFBD><EFBFBD>w<EFBFBD>g<EFBFBD><67><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>I<EFBFBD>ϥΪ̪<CEAA><CCAA>ݨD<DDA8>F<EFBFBD>C
<sect1>
<heading><3E>ڥi<DAA5>H<EFBFBD>z<EFBFBD>L FreeBSD <20>N<EFBFBD>ڪ<EFBFBD> Win95 <20><><EFBFBD><EFBFBD><EFBFBD>s<EFBFBD>W Internet <20><>?</heading>
<p><3E>򥻤W, <20>|<7C>ݳo<DDB3>ذ<EFBFBD><D8B0>D<EFBFBD><44><EFBFBD>H<EFBFBD>b<EFBFBD>a<EFBFBD>̦ܤ֦<DCA4><D6A6><EFBFBD><EFBFBD>x<EFBFBD>q<EFBFBD><71>, <20>@<40>x<EFBFBD>] FreeBSD
<20>t<EFBFBD>~<7E>@<40>x<EFBFBD>] Win95; <20>o<EFBFBD>ӥD<D3A5>N<EFBFBD>O<EFBFBD>N FreeBSD <20>D<EFBFBD><44><EFBFBD>s<EFBFBD>W Internet
,<2C>M<EFBFBD><4D><EFBFBD>z<EFBFBD>L<EFBFBD>o<EFBFBD>x FreeBSD <20>D<EFBFBD><44>,<2C><><EFBFBD>] Win95 <20><><EFBFBD>q<EFBFBD><71><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>W<EFBFBD><57><EFBFBD>C
<20>o<EFBFBD>Ӱ<EFBFBD><D3B0>D<EFBFBD><44><EFBFBD>O<EFBFBD>e<EFBFBD>@<40>Ӱ<EFBFBD><D3B0>D<EFBFBD><44><EFBFBD>@<40>ӯS<D3AF>ҡC
<p><3E>o<EFBFBD>䦳<EFBFBD><E4A6B3><EFBFBD>n<EFBFBD><6E><EFBFBD><EFBFBD><EFBFBD><EFBFBD>,<2C>ЧA<D0A7><41><EFBFBD><EFBFBD><EFBFBD><EFBFBD> FreeBSD <20><><EFBFBD>D<EFBFBD><44><EFBFBD>]<5D>w<EFBFBD><77>
<url url="http://www.ssimicro.com/~jeremyc/ppp.html"
name="PPP Dialup Router">
<p><bf/<2F>`<60>N:/ <20>b<EFBFBD>o<EFBFBD>ت<EFBFBD><D8AA>p<EFBFBD>U<EFBFBD>A<EFBFBD>ܤ֭n<D6AD><6E><EFBFBD><EFBFBD><EFBFBD>ӥH<D3A5>W<EFBFBD><57><EFBFBD>T<EFBFBD>w IP addresses
, <20><><EFBFBD>ɬO<C9AC>T<EFBFBD>ӥH<D3A5>W<EFBFBD>Χ<EFBFBD><CEA7>h<EFBFBD><68> IP <20>P<EFBFBD>ɨϥ<C9A8>, <20><><EFBFBD>A<EFBFBD><41><EFBFBD>ݨD<DDA8>өw<D3A9>C
<20>p<EFBFBD>G<EFBFBD>A<EFBFBD>S<EFBFBD><53><EFBFBD>T<EFBFBD>w<EFBFBD><77> IP <20>i<EFBFBD>H<EFBFBD>ϥ<EFBFBD>,<2C>A<EFBFBD>i<EFBFBD>H<EFBFBD>Ҽ{<7B>ϥ<EFBFBD> private IP
<20>l<EFBFBD><6C><EFBFBD><EFBFBD>,<2C>æw<C3A6><77> <bf/proxies/ <20>Ҧp
<url url="http://squid.nlanr.net/Squid/" name="SQUID"> <20>άO
<url url="http://www.tis.com/" name="the TIS firewall toolkit">
<20>b<EFBFBD>A<EFBFBD><41> FreeBSD <20>D<EFBFBD><44><EFBFBD>W<EFBFBD>C
<p><3E>t<EFBFBD>~<7E>i<EFBFBD>H<EFBFBD>Ѧ<EFBFBD> <ref id="natd">.
<sect1>
<heading>
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڦb compile ISC <20>̷s<CCB7><73><EFBFBD><EFBFBD> BIND <20>{<7B><><EFBFBD>ɦѬO<D1AC><4F><EFBFBD><EFBFBD>?
</heading>
<p><3E>b ``<tt/cdefs.h/'' <20>ɮפ<C9AE><D7A4><EFBFBD><EFBFBD>w<EFBFBD>q<EFBFBD>P FreeBSD <20>t<EFBFBD>Τ<EFBFBD><CEA4><EFBFBD><EFBFBD><EFBFBD>
<20><><EFBFBD>ɮשw<D7A9>q<EFBFBD><71><EFBFBD>ҽĬ<D2BD><C4AC>C<EFBFBD><43><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
<tt>compat/include/sys/cdefs.h</tt> <20>屼<EFBFBD>N<EFBFBD>i<EFBFBD>H<EFBFBD>F<EFBFBD>C
<sect1>
<heading>FreeBSD <20>䴩 SLIP <20>M PPP <20><>?</heading>
<p><3E>O<EFBFBD><4F><EFBFBD>C <20>A<EFBFBD>i<EFBFBD>H<EFBFBD>d<EFBFBD>d man pages <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
<htmlurl url="http://www.freebsd.org/cgi/man.cgi?slattach"
name="slattach">, <htmlurl
url="http://www.freebsd.org/cgi/man.cgi?sliplogin" name="sliplogin">,
<htmlurl url="http://www.freebsd.org/cgi/man.cgi?pppd" name="pppd"> <20>H<EFBFBD><48>
<htmlurl url="http://www.freebsd.org/cgi/man.cgi?ppp" name="ppp"> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>.
<tt/pppd/ <20>M <tt/ppp/ <20><><EFBFBD><EFBFBD><EFBFBD>Ѽ<EFBFBD><D1BC>i<EFBFBD>μ<EFBFBD><CEBC>X<EFBFBD><58><EFBFBD>\<5C><><EFBFBD>C
<htmlurl url="http://www.freebsd.org/cgi/man.cgi?sliplogin"
name="Sliplogin"> <20>M<EFBFBD><4D><EFBFBD>B<EFBFBD>z<EFBFBD><7A><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>J<EFBFBD><4A><EFBFBD>\<5C><>,<2C><>
<htmlurl url="http://www.freebsd.org/cgi/man.cgi?slattach"
name="slattach"> <20>B<EFBFBD>z<EFBFBD><7A><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>X<EFBFBD><58><EFBFBD>\<5C><><EFBFBD>C
<p><3E>o<EFBFBD>ǵ{<7B><><EFBFBD><EFBFBD><EFBFBD>ԲӪ<D4B2><D3AA><EFBFBD><EFBFBD><EFBFBD>,<2C>A<EFBFBD>i<EFBFBD>H<EFBFBD>b
<url url="../handbook/handbook.html" name="handbook"><3E><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>:
<itemize>
<item><url url="../handbook/slips.html"
name="SLIP (server <20><>) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>">
<item><url url="../handbook/slipc.html"
name="SLIP (client <20><>) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>">
<item><url url="../handbook/ppp.html"
name="PPP (kernel <20>Ҧ<EFBFBD>) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>">
<item><url url="../handbook/userppp.html"
name="PPP (<28>ϥΪ̼Ҧ<CCBC>) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>">
</itemize>
<p><3E>p<EFBFBD>G<EFBFBD>A<EFBFBD>u<EFBFBD><75><EFBFBD>ǥ<EFBFBD>"shell account"<22><><EFBFBD>覡<EFBFBD>W<EFBFBD><57><EFBFBD><EFBFBD><EFBFBD><EFBFBD>,
<20>A<EFBFBD>i<EFBFBD><69><EFBFBD>|<7C>Q<EFBFBD>ݬ<EFBFBD> <htmlurl
url="http://www.freebsd.org/cgi/ports.cgi?^slirp" name="slirp">
<20>o<EFBFBD>ӳn<D3B3><6E><EFBFBD>C <20><><EFBFBD>i<EFBFBD>H<EFBFBD><48><EFBFBD>A<EFBFBD><41><EFBFBD>q<EFBFBD><71><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>s<EFBFBD>W (<28>Y<EFBFBD><59>) <20>A<EFBFBD><41>,
<20>Ҧp ftp <20>M http <20><><EFBFBD><EFBFBD><EFBFBD>C
<sect1>
<heading>
FreeBSD <20>䴩 NAT <20><> Masquerading <20><>?<label id="natd">
</heading>
<p><3E>p<EFBFBD>G<EFBFBD>A<EFBFBD><41><EFBFBD>@<40>Ӫ<EFBFBD><D3AA>ݪ<EFBFBD><DDAA>l<EFBFBD><6C><EFBFBD><EFBFBD>(<28><><EFBFBD>@<40>x<EFBFBD>H<EFBFBD>W<EFBFBD><57><EFBFBD><EFBFBD><EFBFBD><EFBFBD>), <20><><EFBFBD>O<EFBFBD>A<EFBFBD><41> Internet provider
<20>o<EFBFBD>u<EFBFBD><75><EFBFBD>t<EFBFBD>@<40><> IP number <20><><EFBFBD>A
(<28>Ϊ̧A<CCA7>u<EFBFBD><75><EFBFBD>t<EFBFBD><74><EFBFBD>@<40>ӰʺA<CABA><41> IP number), <20>A<EFBFBD>i<EFBFBD>H<EFBFBD>Ѧ<EFBFBD>
<htmlurl url="http://www.freebsd.org/cgi/man.cgi?natd" name="natd">
<20>o<EFBFBD>ӵ{<7B><><EFBFBD>C <tt/Natd/ <20><><EFBFBD>A<EFBFBD>i<EFBFBD>H<EFBFBD>z<EFBFBD>L<EFBFBD>o<EFBFBD>@<40><> IP number <20><><EFBFBD><EFBFBD><EFBFBD>Ӥl<D3A4><6C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>q<EFBFBD><71><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
<20>s<EFBFBD>W internet <20>C
<p><htmlurl url="http://www.freebsd.org/cgi/man.cgi?ppp"
name="ppp"> <20>o<EFBFBD>ӵ{<7B><><EFBFBD>]<5D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>\<5C><> , <20>p<EFBFBD>G<EFBFBD>A<EFBFBD>U
<tt/-alias/ <20>o<EFBFBD>ӿﶵ<D3BF><EFB6B5><EFBFBD>ܡC <htmlurl
url="http://www.freebsd.org/cgi/man.cgi?libalias" name="alias library">
<20>b<EFBFBD>o<EFBFBD><6F><EFBFBD>ӳB<D3B3>z<EFBFBD>覡<EFBFBD><E8A6A1><EFBFBD><EFBFBD><EFBFBD>|<7C>Q<EFBFBD>ϥΨ<CFA5><CEA8>C
<sect1>
<heading>
<20>ڤ<EFBFBD><DAA4><EFBFBD><EFBFBD>ϥ<EFBFBD> ppp ,<2C>ڰ<EFBFBD><DAB0><EFBFBD><EFBFBD>F<EFBFBD><46><EFBFBD><EFBFBD><EFBFBD><EFBFBD> ?<label id="userppp">
</heading>
<p><3E>A<EFBFBD><41><EFBFBD>ӥ<EFBFBD><D3A5>ݬ<EFBFBD> <htmlurl
url="http://www.freebsd.org/cgi/man.cgi?ppp" name="ppp man page"> <20>M
<url url="../handbook/userppp.html"
name="ppp <20>ϥλ<CFA5><CEBB><EFBFBD>">. <20>ϥΥH<CEA5>U<EFBFBD><55><EFBFBD>O<EFBFBD>ӥ<EFBFBD><D3A5>}<7D>O<EFBFBD><4F> (logging) <20><><EFBFBD>\<5C><>
<verb>
set log Phase Chat Connect Carrier lcp ipcp ccp command
</verb>
<p><3E>o<EFBFBD>өR<D3A9>O<EFBFBD>i<EFBFBD>H<EFBFBD>b <bf/ppp/ command prompt <20>Ϊ̬O<CCAC>b
<tt>/etc/ppp/ppp.conf</tt> <20>պA<D5BA>ɮפ<C9AE><D7A4>[<5B>J<EFBFBD>C
(<28>[<5B>b <bf>default</bf> section <20><><EFBFBD>}<7D>Y<EFBFBD>̦n).
<20>T<EFBFBD>w<EFBFBD>b <htmlurl
url="http://www.freebsd.org/cgi/man.cgi?syslog.conf"
name="/etc/syslog.conf"> <20>̭<EFBFBD><CCAD><EFBFBD><EFBFBD>o<EFBFBD><6F><EFBFBD>@<40><>:
<verb>
!ppp
*.* /var/log/ppp.log
</verb>
<p><3E>ӥB<tt>/var/log/ppp.log</tt> <20>o<EFBFBD><6F><EFBFBD>ɮצs<D7A6>b<EFBFBD>C <20>p<EFBFBD><70><EFBFBD>@<40><>
<20>A<EFBFBD>i<EFBFBD>H<EFBFBD>q log <20>ɮפ<C9AE><D7A4><EFBFBD><EFBFBD>D<EFBFBD>쩳<EFBFBD>o<EFBFBD>ͤF<CDA4><46><EFBFBD><EFBFBD><EFBFBD>Ʊ<EFBFBD><C6B1>C
<20><><EFBFBD><EFBFBD><EFBFBD>ξ<EFBFBD><CEBE><EFBFBD><EFBFBD>ɮת<C9AE><D7AA><EFBFBD><EFBFBD>e<EFBFBD>A<EFBFBD>ݤ<EFBFBD><DDA4><EFBFBD>, <20>p<EFBFBD>G<EFBFBD>A<EFBFBD>n<EFBFBD>V<EFBFBD>H<EFBFBD>D<EFBFBD>Ϫ<EFBFBD><CFAA><EFBFBD>
, <20>ϧA<CFA7><41><EFBFBD>H<EFBFBD>|<7C>ݱo<DDB1><6F><EFBFBD><EFBFBD><EFBFBD>C
<p><3E>p<EFBFBD>G<EFBFBD>A<EFBFBD>t<EFBFBD>ΤW<CEA4><57><EFBFBD><EFBFBD><EFBFBD><EFBFBD> ppp <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> "set log"
<20><><EFBFBD><EFBFBD><EFBFBD>O<EFBFBD><4F><EFBFBD><EFBFBD>, <20>A<EFBFBD><41><EFBFBD>ӥh<D3A5>U<EFBFBD><55>
<url url="http://www.freebsd.org/~brian" name="<22>̷s<CCB7><73><EFBFBD><EFBFBD>">.
<20>o<EFBFBD>Ӫ<EFBFBD><D3AA><EFBFBD><EFBFBD>b FreeBSD 2.1.5 <20>H<EFBFBD>W<EFBFBD><57><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>i<EFBFBD>H<EFBFBD>ϥΡC
<sect2>
<heading><3E>ڤ@<40><><EFBFBD><EFBFBD> ppp ,<2C><><EFBFBD>N<EFBFBD><4E><EFBFBD>b<EFBFBD><62><EFBFBD>䤣<EFBFBD>ʤF</heading>
<p><3E>|<7C>o<EFBFBD>ͳo<CDB3>ر<EFBFBD><D8B1>γq<CEB3>`<60>O<EFBFBD>A<EFBFBD><41> hostname <20>S<EFBFBD><53><EFBFBD><EFBFBD><EFBFBD>k<EFBFBD>ѥX<D1A5>ӡC <20>ѨM<D1A8>o<EFBFBD>Ӱ<EFBFBD><D3B0>D
<20>̦n<CCA6><6E><EFBFBD><EFBFBD><EFBFBD>k<EFBFBD>O<EFBFBD>T<EFBFBD>w <tt>/etc/hosts</tt> <20>|<7C>Q<EFBFBD>A<EFBFBD><41> resolver <20>Ĥ@<40>ӰѦҨ<D1A6><D2A8>C
<20>A<EFBFBD>i<EFBFBD>H<EFBFBD>ק<EFBFBD><tt>/etc/host.conf</tt>
<20>åB<C3A5><42><tt>hosts</tt> <20><><EFBFBD><EFBFBD><EFBFBD>̫e<CCAB><65>. <20><><EFBFBD><EFBFBD>, <20>u<EFBFBD>n<EFBFBD><6E><EFBFBD>A<EFBFBD><41><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>W<EFBFBD>٩<EFBFBD><D9A9><EFBFBD>
<tt>/etc/hosts</tt> <20>̭<EFBFBD><CCAD>N<EFBFBD>i<EFBFBD>H<EFBFBD>F<EFBFBD>C <20>p<EFBFBD>G<EFBFBD>A<EFBFBD>S<EFBFBD><53>
local network <20><><EFBFBD><EFBFBD>, <20>ק<EFBFBD> <tt>localhost</tt> <20>o<EFBFBD>@<40><>:
<verb>
127.0.0.1 foo.bar.com foo localhost
</verb>
<20>_<EFBFBD>h, <20>N<EFBFBD><4E><EFBFBD>A<EFBFBD>D<EFBFBD><44><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>T<EFBFBD>[<5B>J<EFBFBD>ɮפ<C9AE><D7A4>C <20>A<EFBFBD>i<EFBFBD>H<EFBFBD>Ѧ<EFBFBD>
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> man pages <20>H<EFBFBD><48><EFBFBD>o<EFBFBD>i<EFBFBD>@<40>B<EFBFBD><42><EFBFBD><EFBFBD><EFBFBD>T<EFBFBD>C
<p><3E>p<EFBFBD>G<EFBFBD>A<EFBFBD><41><EFBFBD>Q<EFBFBD><51><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>o<EFBFBD>ǰʧ@, <20>A<EFBFBD><41><EFBFBD>ӥi<D3A5>H<EFBFBD><48><EFBFBD>\<5C><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <tt>ping -c1 `hostname`</tt>
.
<sect2>
<heading>Ppp <20>b -auto <20>Ҧ<EFBFBD><D2A6>U<EFBFBD><55><EFBFBD>༷<EFBFBD><E0BCB7></heading>
<p><3E><><EFBFBD><EFBFBD><EFBFBD>T<EFBFBD>w<EFBFBD>A<EFBFBD><41><EFBFBD><EFBFBD><EFBFBD>w<EFBFBD><77><EFBFBD><EFBFBD> (default route) <20>O<EFBFBD>_<EFBFBD><5F><EFBFBD>]<5D>w<EFBFBD>C <20>U <htmlurl
url="http://www.freebsd.org/cgi/man.cgi?netstat">
name="netstat -rn"> <20>o<EFBFBD>ӫ<EFBFBD><D3AB>O, <20>A<EFBFBD><41><EFBFBD>ӯ<EFBFBD><D3AF><EFBFBD><EFBFBD>ݨ<EFBFBD><DDA8>p<EFBFBD>H<EFBFBD>U<EFBFBD>d<EFBFBD>Ҫ<EFBFBD><D2AA><EFBFBD><EFBFBD><EFBFBD> entries :
<verb>
Destination Gateway Flags Refs Use Netif Expire
default 10.0.0.2 UGSc 0 0 tun0
10.0.0.2 10.0.0.1 UH 0 0 tun0
</verb>
<p>This is assuming that you've used the addresses from the
handbook, the man page or from the ppp.conf.sample file.
If you haven't got a default route, it may be because you're
running an old version of <htmlurl
url="http://www.freebsd.org/cgi/man.cgi?ppp"
name="ppp"> that doesn't understand the
word <tt/HISADDR/ in the ppp.conf file. If your version of
<bf/ppp/ is from before FreeBSD 2.2.5, change the
<verb>
add 0 0 HISADDR
</verb>
<p>line to one saying
<verb>
add 0 0 10.0.0.2
</verb>
<p>Another reason for the default route line being missing is that
you have mistakenly set up a default router in your
<htmlurl url="http://www.freebsd.org/cgi/man.cgi?rc.conf"
name="/etc/rc.conf"> file (this file was called
<tt>/etc/sysconfig</tt> prior to release 2.2.2), and you have
omitted the line saying
<verb>
delete ALL
</verb>
<p>from <tt>ppp.conf</tt>. If this is the case, go back to the
<url url="../handbook/userppp:final.html"
name="Final system configuration"> section of the handbook.
<sect2>
<heading>What does "No route to host" mean</heading>
<p>This error is usually due to a missing
<verb>
MYADDR:
delete ALL
add 0 0 HISADDR
</verb>
<p>section in your <tt>/etc/ppp/ppp.linkup</tt> file. This is
only necessary if you have a dynamic IP address or don't know the
address of your gateway. If you're using interactive mode, you can
type the following after entering <tt/packet mode/ (packet mode is
indicated by the capitalized <bf/PPP/ in the prompt):
<verb>
delete ALL
add 0 0 HISADDR
</verb>
<p>Refer to the <url url="../handbook/userppp:dynamicIP.html"
name="PPP and Dynamic IP addresses"> section of the handbook
for further details.
<sect2>
<heading>My connection drops after about 3 minutes</heading>
<p>The default ppp timeout is 3 minutes. This can be adjusted
with the line
<verb>
set timeout NNN
</verb>
<p>where <bf/NNN/ is the number of seconds of inactivity before the
connection is closed. If <bf/NNN/ is zero, the connection is
never closed due to a timeout. It is possible to put this command in
the <tt>ppp.conf</tt> file, or to type it at the prompt in
interactive mode. It is also possible to adjust it on the fly while
the line is active by connecting to <bf/ppp/s server socket using
<htmlurl url="http://www.freebsd.org/cgi/man.cgi?telnet" name="telnet">
or <htmlurl url="http://www.freebsd.org/cgi/man.cgi?pppctl"
name="pppctl">. Refer to the
<htmlurl url="http://www.freebsd.org/cgi/man.cgi?ppp" name="ppp"> man
page for further details.
<sect2>
<heading>My connection drops under heavy load</heading>
<p>If you have Link Quality Reporting (LQR) configured, it is
possible that too many LQR packets are lost between your
machine and the peer. Ppp deduces that the line must therefore
be bad, and disconnects. Prior to FreeBSD version 2.2.5,
LQR was enabled by default. It is now disabled by default.
LQR can be disabled with the line
<verb>
disable lqr
</verb>
<sect2>
<heading>My connection drops after a random amount of time</heading>
<p>Sometimes, on a noisy phone line or even on a line with
call waiting enabled, your modem may hang up because it
thinks (incorrectly) that it lost carrier.
<p>There's a setting on most modems for determining how tolerant
it should be to temporary losses of carrier. On a USR
Sportster for example, this is measured by the S10 register in
tenths of a second. To make your modem more forgiving, you could
add the following send-expect sequence to your dial string:
<verb>
set dial "...... ATS10=10 OK ......"
</verb>
<p>Refer to your modem manual for details.
<sect2>
<heading>Nothing happens after the Login OK! message</heading>
<p>Prior to FreeBSD version 2.2.5, once the link was established,
<htmlurl url="http://www.freebsd.org/cgi/man.cgi?ppp"
name="ppp"> would wait for the peer to initiate the Line Control
Protocol (LCP). Many ISPs will not initiate negotiations and
expect the client to do so. To force <bf/ppp/ to initiate
the LCP, use the following line:
<verb>
set openmode active
</verb>
<p><bf/Note/: It usually does no harm if both sides initiate
negotiation, so openmode is now active by default. However,
the next section explains when it <bf/does/ do some harm.
<sect2>
<heading>I keep seeing errors about magic being the same</heading>
<p>Occasionally, just after connecting, you may see messages in
the log that say "magic is the same". Sometimes, these
messages are harmless, and sometimes one side or the other
exits. Most ppp implementations cannot survive this problem, and
even if the link seems to come up, you'll see repeated configure
requests and configure acknowledgements in the log file until
ppp eventually gives up and closes the connection.
<p>This normally happens on server machines with slow disks that
are spawning a getty on the port, and executing ppp from a
login script or program after login. I've also heard reports
of it happening consistently when using slirp. The reason is
that in the time taken between getty exiting and ppp starting, the
client-side ppp starts sending Line Control Protocol (LCP)
packets. Because ECHO is still switched on for the port on
the server, the client ppp sees these packets "reflect" back.
<p>One part of the LCP negotiation is to establish a magic number
for each side of the link so that "reflections" can be detected.
The protocol says that when the peer tries to negotiate
the same magic number, a NAK should be sent and a new magic
number should be chosen. During the period that the server
port has ECHO turned on, the client ppp sends LCP packets,
sees the same magic in the reflected packet and NAKs it. It
also sees the NAK reflect (which also means ppp must change
its magic). This produces a potentially enormous number of
magic number changes, all of which are happily piling into
the server's tty buffer. As soon as ppp starts on the server,
it's flooded with magic number changes and almost immediately
decides it's tried enough to negotiate LCP and gives up.
Meanwhile, the client, who no longer sees the reflections,
becomes happy just in time to see a hangup from the server.
<p>This can be avoided by allowing the peer to start negotiating
with the following line in your ppp.conf file:
<verb>
set openmode passive
</verb>
<p>This tells ppp to wait for the server to initiate LCP
negotiations. Some servers however may never initiate negotiations.
If this is the case, you can do something like:
<verb>
set openmode active 3
</verb>
<p>This tells ppp to be passive for 3 seconds, and then to start
sending LCP requests. If the peer starts sending requests during
this period, ppp will immediately respond rather than waiting for
the full 3 second period.
<sect2>
<heading>
LCP negotiations continue 'till the connection is closed
</heading>
<p>There is currently an implementation mis-feature in <bf/ppp/
where it doesn't associate LCP, CCP &amp; IPCP responses with
their original requests. As a result, if one <bf/ppp/
implementation is more than 6 seconds slower than the other side,
the other side will send two additional LCP configuration requests.
This is fatal.
Consider two implementations, <bf/A/ and <bf/B/. <bf/A/ starts
sending LCP requests immediately after connecting and <bf/B/ takes
7 seconds to start. When <bf/B/ starts, <bf/A/ has sent 3 LCP
REQs. We're assuming the line has ECHO switched off, otherwise
we'd see magic number problems as described in the previous section.
<bf/B/ sends a REQ, then an ACK to the first of <bf/A/'s REQs.
This results in <bf/A/ entering the <bf/OPENED/ state and sending
and ACK (the first) back to <bf/B/. In the meantime, <bf/B/ sends
back two more ACKs in response to the two additional REQs sent by
<bf/A/ before <bf/B/ started up. <bf/B/ then receives the first
ACK from <bf/A/ and enters the <bf/OPENED/ state. <bf/A/ receives
the second ACK from <bf/B/ and goes back to the <bf/REQ-SENT/ state,
sending another (forth) REQ as per the RFC. It then receives the
third ACK and enters the <bf/OPENED/ state. In the meantime,
<bf/B/ receives the forth REQ from <bf/A/, resulting in it reverting
to the <bf/ACK-SENT/ state and sending another (second) REQ and
(forth) ACK as per the RFC. <bf/A/ gets the REQ, goes into
<bf/REQ-SENT/ and sends another REQ. It immediately receives the
following ACK and enters <bf/OPENED/.
<p>This goes on 'till one side figures out that they're getting
nowhere and gives up.
<p>The best way to avoid this is to configure one side to be
<bf/passive/ - that is, make one side wait for the other to start
negotiating. This can be done with the
<verb>
set openmode passive
</verb>
command. Care should be taken with this option. You should also
use the
<verb>
set stopped N
</verb>
command to limit the amount of time that <bf/ppp/ waits for the peer
to begin negotiations. Alternatively, the
<verb>
set openmode active N
</verb>
command (where <bf/N/ is the number of seconds to wait before
starting negotiations) can be used. Check the manual page for
details.
<sect2>
<heading>Ppp locks up shortly after connecting</heading>
<p>Prior to version 2.2.5 of FreeBSD, it was possible that your
link was disabled shortly after connection due to <bf/ppp/
mis-handling Predictor1 compression negotiation. This would
only happen if both sides tried to negotiate different
Compression Control Protocols (CCP). This problem is now
corrected, but if you're still running an old version of
<bf/ppp/, the problem can be circumvented with the line
<verb>
disable pred1
</verb>
<sect2>
<heading>Ppp locks up when I shell out to test it</heading>
<p>When you execute the <tt/shell/ or <tt/!/ command, <bf/ppp/
executes a shell (or if you've passed any arguements, <bf/ppp/
will execute those arguements). Ppp will wait for the command
to complete before continuing. If you attempt to use the
ppp link while running the command, the link will appear to have
frozen. This is because <bf/ppp/ is waiting for the command
to complete.
<p>If you wish to execute commands like this, use the
<tt/!bg/ command instead. This will execute the given command
in the background, and ppp can continue to service the link.
<sect2>
<heading>Ppp over a null-modem cable never exits</heading>
<p>There is no way for <bf/ppp/ to automatically determine that
a direct connection has been dropped. This is due to the
lines that are used in a null-modem serial cable. When using
this sort of connection, LQR should always be enabled with
the line
<verb>
enable lqr
</verb>
<p>LQR is accepted by default if negotiated by the peer.
<sect2>
<heading>Why does ppp dial for no reason in -auto mode</heading>
<p>If <bf/ppp/ is dialing unexpectedly, you must determine the
cause, and set up Dial filters (dfilters) to prevent such dialing.
<p>To determine the cause, use the following line:
<verb>
set log +tcp/ip
</verb>
<p>This will log all traffic through the connection. The next
time the line comes up unexpectedly, you will see the reason
logged with a convenient timestamp next to it.
<p>You can now disable dialing under these circumstances. Usually,
this sort of problem arises due to DNS lookups. To prevent
DNS lookups from establishing a connection (this will <bf/not/
prevent <bf/ppp/ from passing the packets through an established
connection), use the following:
<verb>
set dfilter 1 deny udp src eq 53
set dfilter 2 deny udp dst eq 53
set dfilter 3 permit 0/0 0/0
</verb>
<p>This is not always suitable, as it will effectively break your
demand-dial capabilities - most programs will need a DNS lookup
before doing any other network related things.
<p>In the DNS case, you should try to determine what is actually
trying to resolve a host name. A lot of the time,
<htmlurl url="http://www.freebsd.org/cgi/man.cgi?sendmail"
name="sendmail"> is the culprit. You should make sure that you tell
sendmail not to do any DNS lookups in its configuration file. See
the section on <ref id="ispmail" name="Mail Configuration"> for
details on how to create your own configuration file and what should
go into it. You may also want to add the following line to your
<bf/.mc/ file:
<verb>
define(`confDELIVERY_MODE', `d')dnl
</verb>
<p>This will make sendmail queue everything until the queue is
run (usually, sendmail is invoked with ``-bd -q30m'', telling it
to run the queue every 30 minutes) or until a ``sendmail -q''
is done (perhaps from your ppp.linkup file).
<sect2>
<heading>What do these CCP errors mean</heading>
<p>I keep seeing the following errors in my log file:
<verb>
CCP: CcpSendConfigReq
CCP: Received Terminate Ack (1) state = Req-Sent (6)
</verb>
<p>This is because ppp is trying to negotiate Predictor1
compression, and the peer does not want to negotiate any
compression at all. The messages are harmless, but if you
wish to remove them, you can disable Predictor1 compression
locally too:
<verb>
disable pred1
</verb>
<sect2>
<heading>Ppp locks up during file transfers with IO errors</heading>
<p>Under FreeBSD 2.2.2 and before, there was a bug in the tun
driver that prevents incoming packets of a size larger than
the tun interface's MTU size. Receipt of a packet greater than
the MTU size results in an IO error being logged via syslogd.
<p>The ppp specification says that an MRU of 1500 should
<bf>always</bf> be accepted as a minimum, despite any LCP
negotiations, therefore it is possible that should you decrease
the MTU to less than 1500, your ISP will transmit packets of
1500 regardless, and you will tickle this non-feature - locking
up your link.
<p>The problem can be circumvented by never setting an MTU of
less than 1500 under FreeBSD 2.2.2 or before.
<sect2>
<heading>Why doesn't ppp log my connection speed?</heading>
<p>In order to log all lines of your modem ``conversation'',
you must enable the following:
<verb>
set log +connect
</verb>
<p>This will make
<htmlurl url="http://www.freebsd.org/cgi/man.cgi?ppp" name="ppp">
log everything up until the last requested "expect" string.
<p>If you wish to see your connect speed and are using PAP or CHAP
(and therefore don't have anything to "chat" after the CONNECT
in the dial script - no "set login" script), you must make sure that
you instruct ppp to "expect" the whole CONNECT line, something like
this:
<verb>
set dial "ABORT BUSY ABORT NO\\sCARRIER TIMEOUT 4 \"\" ATZ OK-ATZ-OK ATDT\\T TIMEOUT 60 CONNECT \\c \\n"
</verb>
<p>Here, we get our CONNECT, send nothing, then expect a line-feed,
forcing <bf/ppp/ to read the whole CONNECT response.
<sect2>
<heading>Ppp ignores the `\' character in my chat script</heading>
<p>Ppp parses each line in your config files so that it can
interpret strings such as <tt/set phone "123 456 789"/ correctly
(and realize that the number is actually only <bf/one/ argument.
In order to specify a ``"'' character, you must escape it using
a backslash (``\'').
<p>When the chat interpreter parses each argument, it re-interprets
the argument in order to find any special escape sequences such
as ``\P'' or ``\T'' (see the man page). As a result of this
double-parsing, you must remember to use the correct number of
escapes.
<p>If you wish to actually send a ``\'' character to (say) your
modem, you'd need something like:
<verb>
set dial "\"\" ATZ OK-ATZ-OK AT\\\\X OK"
</verb>
<p>resulting in the following sequence:
<verb>
ATZ
OK
AT\X
OK
</verb>
<p>or
<verb>
set phone 1234567
set dial "\"\" ATZ OK ATDT\\T"
</verb>
<p>resulting in the following sequence:
<verb>
ATZ
OK
ATDT1234567
</verb>
<sect2>
<heading>Ppp gets a seg-fault, but I see no <tt/ppp.core/ file</heading>
<p>Ppp (or any other program for that matter) should never
dump core. Because ppp runs with an effective user id of 0,
the operating system will not write ppps core image to disk
before terminating it. If, however ppp <bf/is/ actually
termating due to a segmentation violation or some other
signal that normally causes core to be dumped, <bf/and/ you're
sure you're using the latest version (see the start of this
section), then you should do the following:
<verb>
$ tar xfz ppp-*.src.tar.gz
$ cd ppp*/ppp
$ echo STRIP= >>Makefile
$ echo CFLAGS+=-g >>Makefile
$ make clean all
$ su
# make install
# chmod 555 /usr/sbin/ppp
</verb>
<p>You will now have a debuggable version of ppp installed. You
will have to be root to run ppp as all of its privileges have
been revoked. When you start ppp, take a careful note of what
your current directory was at the time.
<p>Now, if and when ppp receives the segmentation violation, it
will dump a core file called ppp.core. You should then do the
following:
<verb>
$ su
# gdb /usr/sbin/ppp ppp.core
(gdb) bt
.....
(gdb) f 0
.....
(gdb) i args
.....
(gdb) l
.....
</verb>
<p>All of this information should be given alongside your
question, making it possible to diagnose the problem.
<p>If you're familiar with gdb, you may wish to find out some
other bits and pieces such as what actually caused the dump and
the addresses & values of the relevant variables.
<sect2>
<heading>
The process that forces a dial in auto mode never connects
</heading>
<p>This was a known problem with <bf/ppp/ set up to negotiate
a dynamic local IP number with the peer in auto mode. It is
fixed in the latest version - search the man page for <bf/iface/.
<p>The problem was that when that initial program calls
<htmlurl url="http://www.freebsd.org/cgi/man.cgi?connect"
name="connect(2)">, the IP number of the tun interface is
assigned to the socket endpoint. The kernel creates the first
outgoing packet and writes it to the tun device. <bf/Ppp/ then
reads the packet and establishes a connection. If, as a result
of <bf/ppp/s dynamic IP assignment, the interface address is changed,
the original socket endpoint will be invalid. Any subsequent
packets sent to the peer will usually be dropped. Even if
they aren't, any responses will not route back to the originating
machine as the IP number is no longer owned by that machine.
<p>There are several theoretical ways to approach this problem.
It would be nicest if the peer would re-assign the same IP number
if possible <tt/:-)/ The current version of <bf/ppp/ does this,
but most other implementations don't.
<p>The easiest method from our side would be to never change the
tun interface IP number, but instead to change all outgoing packets
so that the source IP number is changed from the interface IP to
the negotiated IP on the fly. This is essentially what the
<tt/iface-alias/ option in the latest version of <bf/ppp/ is
doing (with the help of <htmlurl
url="http://www.freebsd.org/cgi/man.cgi?libalias" name="libalias(3)">
and ppp's <bf/-alias/ switch) - it's maintaining all previous
interface addresses and aliasing them to the last negotiated address.
<p>Another alternative (and probably the most reliable) would be
to implement a system call that changes all bound sockets from one
IP to another. <bf/Ppp/ would use this call to modify the
sockets of all existing programs when a new IP number is
negotiated. The same system call could be used by dhcp clients
when they are forced to re-bind() their sockets.
<p>Yet another possibility is to allow an interface to be brought
up without an IP number. Outgoing packets would be given
an IP number of 255.255.255.255 up until the first SIOCAIFADDR
ioctl is done. This would result in fully binding the socket. It
would be up to <bf/ppp/ to change the source IP number, but only if
it's set to 255.255.255.255, and only the IP number and IP checksum
would need to change. This, however is a bit of a hack as
the kernel would be sending bad packets to an improperly
configured interface, on the assumption that some other mechanism
is capable of fixing things retrospectively.
<sect2>
<heading>Why don't most games work with the -alias switch</heading>
<p>The reason games and the like don't work when libalias is
in use is that the machine on the outside will try to open a
connection or send (unsolicited) UDP packets to the machine
on the inside. The packet alias software doesn't know that
it should send these packets to the interior machine.
<p>To make things work, make sure that the only thing running
is the software that you're having problems with, then either
run tcpdump on the tun interface of the gateway or enable ppp
tcp/ip logging (``set log +tcp/ip'') on the gateway.
<p>When you start the offending software, you should see packets
passing through the gateway machine. When something comes back
from the outside, it'll be dropped (that's the problem). Note
the port number of these packets then shut down the offending
software. Do this a few times to see if the port numbers are
consistent. If they are, then the following line in the relevant
section of /etc/ppp/ppp.conf will make the software functional:
<verb>
alias port proto internalmachine:port port
</verb>
<p>where ``proto'' is either ``tcp'' or ``udp'',
``internalmachine'' is the machine that you want the packets
to be sent to and ``port'' is the destination port number of
the packets.
<p>You won't be able to use the software on other machines
without changing the above command, and running the software
on two internal machines at the same time is out of the question
- after all, the outside world is seeing your entire internal
network as being just a single machine.
<p>If the port numbers aren't consistent, there are three more
options:
<p><bf>1)</bf> Submit support in libalias. Examples of ``special
cases'' can be found in /usr/src/lib/libalias/alias_*.c (alias_ftp.c
is a good prototype). This usually involves reading certain
recognised outgoing packets, identifying the instruction that
tells the outside machine to initiate a connection back to the
internal machine on a specific (random) port and setting up a
``route'' in the alias table so that the subsequent packets
know where to go.
<p>This is the most difficult solution, but it is the best and
will make the software work with multiple machines.
<p><bf>2)</bf> Use a proxy. The application may support socks5
for example, or (as in the ``cvsup'' case) may have a ``passive''
option that avoids ever requesting that the peer open connections
back to the local machine.
<p><bf>3)</bf> Redirect everything to the internal machine using
``alias addr''. This is the sledge-hammer approach.
<sect2>
<heading>What are FCS errors ?</heading>
<p>FCS stands for <bf/F/rame <bf/C/heck <bf/S/equence. Each
ppp packet has a checksum attached to ensure that the data
being received is the data being sent. If the FCS of an
incoming packet is incorrect, the packet is dropped and the
HDLC FCS count is increased. The HDLC error values can be
displayed using the <tt>show hdlc</tt> command.
<p>If your link is bad (or if your serial driver is dropping
packets), you will see the occasional FCS error. This is not
usually worth worrying about although it does slow down the
compression protocols substantially. If you have an external
modem, make sure your cable is properly shielded from
interference - this may eradicate the problem.
<p>If your link freezes as soon as you've connected and you see
a large number of FCS errors, this may be because your link is
not 8 bit clean. Make sure your modem is not using software
flow control (XON/XOFF). If your datalink <bf>must</bf> use
software flow control, use the command
<tt>set accmap 0x000a0000</tt> to tell <bf>ppp</bf> to escape
the ^Q and ^S characters.
<p>Another reason for seeing too many FCS errors may be that
the remote end has stopped talking <bf/PPP/. You may want to
enable <tt/async/ logging at this point to determine if the
incoming data is actually a login or shell prompt. If you
have a shell prompt at the remote end, it's possible to
terminate ppp without dropping the line by using the
<tt>close lcp</tt> command (a following <tt>term</tt> command
will reconnect you to the shell on the remote machine.
<p>If nothing in your log file indicates why the link might
have been terminated, you should ask the remote administrator
(your ISP?) why the session was terminated.
<sect2>
<heading>None of this helps - I'm desperate !</heading>
<p>If all else fails, send as much information as you can,
including your config files, how you're starting <bf/ppp/,
the relevant parts of your log file and the output of the
<htmlurl url="http://www.freebsd.org/cgi/man.cgi?netstat"
name="netstat -rn"> command (before and after connecting) to the
<url url="mailto:freebsd-questions@FreeBSD.org"
name="freebsd-questions@FreeBSD.org"> mailing list or the
<url url="news:comp.unix.bsd.freebsd.misc"
name="comp.unix.bsd.freebsd.misc"> news group, and someone
should point you in the right direction.
<sect1>
<heading>I can't create a <tt>/dev/ed0</tt> device!</heading>
<p>In the Berkeley networking framework, network interfaces are only
directly accessible by kernel code. Please see the
<tt>/etc/rc.network</tt> file and the manual pages for the various
network programs mentioned there for more information. If this
leaves you totally confused, then you should pick up a book
describing network administration on another BSD-related
operating system; with few significant exceptions, administering
networking on FreeBSD is basically the same as on SunOS 4.0 or
Ultrix.
<sect1>
<heading>How can I setup Ethernet aliases?</heading>
<p>Add ``<tt/netmask 0xffffffff/'' to your <htmlurl
url="http://www.freebsd.org/cgi/man.cgi?ifconfig" name="ifconfig">
command-line like the following:
<verb>
ifconfig ed0 alias 204.141.95.2 netmask 0xffffffff
</verb>
<sect1>
<heading>How do I get my 3C503 to use the other network port?</heading>
<p>If you want to use the other ports, you'll have to specify an
additional parameter on the
<htmlurl url="http://www.freebsd.org/cgi/man.cgi?ifconfig"
name="ifconfig"> command line. The
default port is ``<tt/link0/''. To use the AUI port instead of
the BNC one, use ``<tt/link2/''. These flags should be specified
using the ifconfig_* variables in <htmlurl
url="http://www.freebsd.org/cgi/man.cgi?rc.conf" name="/etc/rc.conf">.
<sect1>
<heading>I'm having problems with NFS to/from FreeBSD.</heading>
<p>Certain PC network cards are better than others (to put it
mildly) and can sometimes cause problems with network intensive
applications like NFS.
<p>See <url url="../handbook/nfs.html" name="the Handbook entry on NFS">
for more information on this topic.
<sect1>
<heading>Why can't I NFS-mount from a Linux box?</heading>
<p>Some versions of the Linux NFS code only accept mount requests
from a privileged port; try
<verb>
mount -o -P linuxbox:/blah /mnt
</verb>
<sect1>
<heading>Why can't I NFS-mount from a Sun box?</heading>
<p>Sun workstations running SunOS 4.X only accept mount requests
from a privileged port; try
<verb>
mount -o -P sunbox:/blah /mnt
</verb>
<sect1>
<heading>I'm having problems talking PPP to NeXTStep machines.</heading>
<p>Try disabling the TCP extensions in <htmlurl
url="http://www.freebsd.org/cgi/man.cgi?rc.conf" name="/etc/rc.conf"> by
changing the following variable to NO:
<verb>
tcp_extensions=NO
</verb>
<p>Xylogic's Annex boxes are also broken in this regard and you must
use the above change to connect thru them.
<sect1>
<heading>How do I enable IP multicast support?</heading>
<p>Multicast host operations are fully supported in FreeBSD 2.0 and
later by default. If you want your box to run as a multicast router,
you will need to recompile your kernel with the <tt>MROUTING</tt>
option and run <tt/mrouted/. FreeBSD 2.2 and later will start
<tt/mrouted/ at boot time if the flag <tt/mrouted_enable/ is set
to "YES" in <tt>/etc/rc.conf</tt>.
<p>MBONE tools are available in their own ports category, mbone. If
you are looking for the conference tools <tt/vic/ and <tt/vat/,
look there!
<p>For more information, see the
<url url="http://www.mbone.com/" name="Mbone Information Web">.
<sect1>
<heading>Which network cards are based on the DEC PCI chipset?</heading>
<p>Here is a list compiled by <url url="mailto:gfoster@driver.nsta.org"
name="Glen Foster">, with some more modern additions:
<verb>
Vendor Model
----------------------------------------------
ASUS PCI-L101-TB
Accton ENI1203
Cogent EM960PCI
Compex ENET32-PCI
D-Link DE-530
Dayna DP1203, DP2100
DEC DE435
Danpex EN-9400P3
JCIS Condor JC1260
Linksys EtherPCI
Mylex LNP101
SMC EtherPower 10/100 (Model 9332)
SMC EtherPower (Model 8432)
TopWare TE-3500P
Zynx ZX342
</verb>
<sect1>
<heading>Why do I have to use the FQDN for hosts on my site?</heading>
<p>You will probably find that the host is actually in a different
domain; for example, if you are in foo.bar.edu and you wish to reach
a host called ``mumble'' in the bar.edu domain, you will have to
refer to it by the fully-qualified domain name, ``mumble.bar.edu'',
instead of just ``mumble''.
<p>Traditionally, this was allowed by BSD BIND resolvers. However
the current version of <htmlurl
url="http://www.freebsd.org/cgi/man.cgi?named" name="bind"> that ships
with FreeBSD no longer provides default abbreviations for non-fully
qualified domain names other than the domain you are in.
So an unqualified host <tt>mumble</tt> must either be found
as <tt>mumble.foo.bar.edu</tt>, or it will be searched for
in the root domain.
<p>This is different from the previous behavior, where the
search continued across <tt>mumble.bar.edu</tt>, and
<tt>mumble.edu</tt>. Have a look at RFC 1535 for why this
was considered bad practice, or even a security hole.
<p>As a good workaround, you can place the line
<verb>
search foo.bar.edu bar.edu
</verb>
<p>instead of the previous
<verb>
domain foo.bar.edu
</verb>
<p>into your <htmlurl url="http://www.freebsd.org/cgi/man.cgi?resolv.conf"
name="/etc/resolv.conf"> file. However, make sure that the search order
does not go beyond the ``boundary between local and public
administration'', as RFC 1535 calls it.
<sect1>
<heading>``Permission denied'' for all networking operations.</heading>
<p>If you have compiled your kernel with the <tt/IPFIREWALL/
option, you need to be aware that the default policy as of
2.1.7R (this actually changed during 2.1-STABLE development)
is to deny all packets that are not explicitly allowed.
<p>If you had unintentionally misconfigured your system for
firewalling, you can restore network operability by typing
the following while logged in as root:
<verb>
ipfw add 65534 allow all from any to any
</verb>
<p>You can also set "firewall_type='open'" in <tt>/etc/rc.conf</tt>.
<p>For further information on configuring a FreeBSD firewall,
see the <url url="../handbook/firewalls.html" name="Handbook section">.
<sect1>
<heading>How much overhead does IPFW incur?</heading>
<p>The answer to this depends mostly on your rule set and processor
speed. For most applications dealing with ethernet and small
rule sets, the answer is, negligible. For those of you that need
actual measurements to satisfy your curiosity, read on.
<p>The following measurements were made using 2.2.5-STABLE on
a 486-66. IPFW was modified to measure the time spent within
the <tt/ip_fw_chk/ routine, displaying the results to the console
every 1000 packets.
<p>Two rule sets, each with 1000 rules were tested. The first set
was designed to demonstrate a worst case scenario by repeating the
rule:
<verb>
ipfw add deny tcp from any to any 55555
</verb>
<p>This demonstrates worst case by causing most of IPFW's packet
check routine to be executed before finally deciding that the
packet does not match the rule (by virtue of the port number).
Following the 999th iteration of this rule was an <tt>allow ip
from any to any</tt>.
<p>The second set of rules were designed to abort the rule
check quickly:
<verb>
ipfw add deny ip from 1.2.3.4 to 1.2.3.4
</verb>
<p>The nonmatching source IP address for the above rule causes
these rules to be skipped very quickly. As before, the 1000th
rule was an <tt>allow ip from any to any</tt>.
<p>The per-packet processing overhead in the former case was
approximately 2.703ms/packet, or roughly 2.7 microseconds per
rule. Thus the theoretical packet processing limit with these
rules is around 370 packets per second. Assuming 10Mbps ethernet
and a ~1500 byte packet size, we would only be able to achieve a
55.5% bandwidth utilization.
<p>For the latter case each packet was processed in
approximately 1.172ms, or roughly 1.2 microseconds per rule.
The theoretical packet processing limit here would be about
853 packets per second, which could consume 10Mbps ethernet
bandwidth.
<p>The excessive number of rules tested and the nature of those
rules do not provide a real-world scenario -- they were used only
to generate the timing information presented here. Here are a
few things to keep in mind when building an efficient rule set:
<itemize>
<item>Place an `established' rule early on to handle the
majority of TCP traffic. Don't put any <tt>allow tcp</tt>
statements before this rule.
<item>Place heavily triggered rules earlier in the rule
set than those rarely used (<bf>without changing the
permissiveness of the firewall</bf>, of course). You can see
which rules are used most often by examining the packet counting
statistics with <tt>ipfw -a l</tt>.
</itemize>
<sect1>
<heading>How can I redirect service requests from one machine to another?
</heading>
<p>You can redirect FTP (and other service) request with the 'socket'
package, available in the ports tree in category 'sysutils'.
Simply replace the service's commandline to call socket instead, like so:
<verb>
ftp stream tcp nowait nobody /usr/local/bin/socket socket ftp.foo.com ftp
</verb>
<p>where 'ftp.foo.com' and 'ftp' are the host and port to redirect to,
respectively.
<sect1>
<heading>Where can I get a bandwidth management tool?</heading>
<p>There are two bandwidth management tools available for FreeBSD.
<url url="http://www.csl.sony.co.jp/person/kjc/programs.html"
name="ALTQ"> is available for free; Bandwidth Manager from
<url url="http://www.etinc.com" name="Emerging Technologies"> is
a commercial product.
</sect>
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