Date: Sun, 27 Oct 2002 14:54:38 -0800 From: Lars Eggert <larse@ISI.EDU> To: Lars Eggert <larse@ISI.EDU> Cc: Luigi Rizzo <rizzo@icir.org>, net@FreeBSD.ORG Subject: Re: Bridging when one interface has no carrier Message-ID: <3DBC6EAE.8090301@isi.edu> In-Reply-To: <3D61224B.2020902@isi.edu> References: <3D61224B.2020902@isi.edu> <20020819102951.A38869@iguana.icir.org> <3DB885BD.8010203@isi.edu>
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[-- Attachment #1 --] Lars Eggert wrote: > This causes the problem decribed in PR kern/41632 > (http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/41632), where dhcpd > "listens" on interface A which is bridged to interface B. When A has no > carrier, DHCP requests arriving on B are ignored. When A has a carrier, > dhcp will get a copy of the packet when it is bridge-forwarded out A, so > the problem doesn't occur then. > > Attached is a rough patch to if_ethersubr.c that fixes the problem. That patch (new version attached) turned out to only fix part of the problem. When bridge-forwarding packets to an interface without a carrier, they start to fill up its outbout queue. Once the queue is full, new packets that are routed to that interfaces won't be bridged anymore. This happens in the example above with dhcpd. DHCP requests come in on B and get bridge-forwarded to A (filling up A's outbound queue). dhcpd generates responses, which are sent via A and then bridge-forwarded to B. Once A's outbound queue is full, those responses fall on the floor. Attached is an ugly hack that fixes this in my setup. The next issue is bridge interactions with IPv6 stateless autoconf. IPv6 doesn't like link-local addresses appearing on (apparently) different interfaces... Lars -- Lars Eggert <larse@isi.edu> USC Information Sciences Institute [-- Attachment #2 --] 0 *H 01 0 + 0 *H 080fErtcvE.0 *H 01 0 UZA10U Western Cape10U Cape Town10U Thawte Consulting1(0&U Certification Services Division1$0"UThawte Personal Freemail CA1+0) *H personal-freemail@thawte.com0 000830000000Z 040827235959Z01 0 UZA10U Western Cape10U Cape Town10 U Thawte1 0U Certificate Services1(0&U Personal Freemail RSA 2000.8.3000 *H 0 32c %E>nx'gڈD)c5*mp<ܮto034qmOe KaU5u'rװ |CBPQ<9TIf - ki N0L0)U "0 0 10UPrivateLabel1-2970U 0 0 U 0 *H 1KG]qSl]y=&b""I'{9$ *8PUl LGl X1B li+@]jy.%݊ Z<D&iHΥbb090%A0 *H 01 0 UZA10U Western Cape10U Cape Town10 U Thawte1 0U Certificate Services1(0&U Personal Freemail RSA 2000.8.300 020824185339Z 030824185339Z0T10 UEggert1 0 U*Lars10U Lars Eggert1 0 *H larse@isi.edu0"0 *H 0 6Fxΰ7a ED&0+Dj)ֽXCUcnleijmz~S0J jWV~ 1^({IݛLjӖ ao:bP}WLVܱ욗cD ɖ_Kv.A(W4 9;Z8-uXE 6b @_0%#d` Rto5 L0R`w@7 r Hcc U 3%7 N_o V0T0*+e!0 00L2uMyffBNUbNJJcdZ2s0U 0 larse@isi.edu0 U 0 0 *H ]Ȕ,fK< cj RZeLa n@Z6,= fK?yO#8+ Ni*LSfpQg <(aӒ$kTx_AL1>ގ|S090%A0 *H 01 0 UZA10U Western Cape10U Cape Town10 U Thawte1 0U Certificate Services1(0&U Personal Freemail RSA 2000.8.300 020824185339Z 030824185339Z0T10 UEggert1 0 U*Lars10U Lars Eggert1 0 *H larse@isi.edu0"0 *H 0 6Fxΰ7a ED&0+Dj)ֽXCUcnleijmz~S0J jWV~ 1^({IݛLjӖ ao:bP}WLVܱ욗cD ɖ_Kv.A(W4 9;Z8-uXE 6b @_0%#d` Rto5 L0R`w@7 r Hcc U 3%7 N_o V0T0*+e!0 00L2uMyffBNUbNJJcdZ2s0U 0 larse@isi.edu0 U 0 0 *H ]Ȕ,fK< cj RZeLa n@Z6,= fK?yO#8+ Ni*LSfpQg <(aӒ$kTx_AL1>ގ|S10001 0 UZA10U Western Cape10U Cape Town10 U Thawte1 0U Certificate Services1(0&U Personal Freemail RSA 2000.8.30%A0 + 0 *H 1 *H 0 *H 1 021027225439Z0# *H 1Nvn`̮ItӢWbo(0R *H 1E0C0 *H 0*H 0 *H @0+0 *H (0 +71001 0 UZA10U Western Cape10U Cape Town10 U Thawte1 0U Certificate Services1(0&U Personal Freemail RSA 2000.8.30%A0 *H 101 0 UZA10U Western Cape10U Cape Town10 U Thawte1 0U Certificate Services1(0&U Personal Freemail RSA 2000.8.30%A0 *H \^E;AMH 6Yz|k`m42}z(Jcm,e\ 5|W$\ؽSHw;L ${bFF)9q#H炷VbҸz_$?s (N퍀! wP] i:z!ځ+`w P7+Lk ._C"GJ1 U: !wWD
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