* Re: IPv6 and private net with masquerading not working correctly [not found] ` <55C4ABF6.3080407@wiesinger.com> @ 2015-08-10 17:39 ` Cong Wang 2015-10-25 7:52 ` Gerhard Wiesinger 0 siblings, 1 reply; 2+ messages in thread From: Cong Wang @ 2015-08-10 17:39 UTC (permalink / raw) To: Gerhard Wiesinger; +Cc: LKML, Linux Kernel Network Developers, netfilter-devel (Cc'ing netdev and netfilter-devel) On Fri, Aug 7, 2015 at 6:00 AM, Gerhard Wiesinger <lists@wiesinger.com> wrote: > On 06.08.2015 20:43, Gerhard Wiesinger wrote: >> >> Hello, >> >> I'm having the following problem with IPv6 and a private internal LAN >> which will be masqueraded to the public internet (I don't want to have >> public IPs in the LAN because of some static IPs and tracking) . Rules are >> generated by shorewall. >> >> Problem is that ICMP6 packets source address is not translated by the >> kernel on the reply when MTU has to be discovered because of too big packets >> and limited MTU capabilities on the path (happens also on tcp6 which works >> thereofore not correctly). >> >> # From an internal host on net fd00:1234:5678::/64 >> ping6 -s 2000 2a02:1234:5678:7::2 >> >> /etc/shorewall6/masq >> EXT_IF fc00::/7 >> >> ip6tables rule: >> MASQUERADE all * * fc00::/7 ::/0 >> >> # Internal interface >> IP6 fd00:1234:5678::9 > 2a02:1234:5678:7::2: frag (0|1432) ICMP6, echo >> request, seq 1, length 1432 >> IP6 fd00:1234:5678::9 > 2a02:1234:5678:7::2: frag (1432|576) >> IP6 2a02:1234:5678:9abc::115 > fd00:1234:5678::9: ICMP6, packet too big, >> mtu 1440, length 1240 >> >> # External interface >> IP6 2001:1234:5678:9abc::1 > 2a02:1234:5678:7::2: frag (0|1432) ICMP6, >> echo request, seq 1, length 1432 >> IP6 2001:1234:5678:9abc::1 > 2a02:1234:5678:7::2: frag (1432|576) >> IP6 2a02:1234:5678:9abc::115 > 2001:1234:5678:9abc::1: ICMP6, packet too >> big, mtu 1440, length 1240 >> >> Looks to me like a a major kernel bug. >> Kernel version is: 4.1.3-201.fc22.x86_64 from Fedora 22 >> >> Any ideas? >> > > Any comments? > > Ciao, > Gerhard > > -- > http://www.wiesinger.com/ > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ ^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: IPv6 and private net with masquerading not working correctly 2015-08-10 17:39 ` IPv6 and private net with masquerading not working correctly Cong Wang @ 2015-10-25 7:52 ` Gerhard Wiesinger 0 siblings, 0 replies; 2+ messages in thread From: Gerhard Wiesinger @ 2015-10-25 7:52 UTC (permalink / raw) To: LKML, Linux Kernel Network Developers, netfilter-devel; +Cc: Cong Wang Any update on this issue? Thank you. Ciao, Gerhard On 10.08.2015 19:39, Cong Wang wrote: > (Cc'ing netdev and netfilter-devel) > > On Fri, Aug 7, 2015 at 6:00 AM, Gerhard Wiesinger <lists@wiesinger.com> wrote: >> On 06.08.2015 20:43, Gerhard Wiesinger wrote: >>> Hello, >>> >>> I'm having the following problem with IPv6 and a private internal LAN >>> which will be masqueraded to the public internet (I don't want to have >>> public IPs in the LAN because of some static IPs and tracking) . Rules are >>> generated by shorewall. >>> >>> Problem is that ICMP6 packets source address is not translated by the >>> kernel on the reply when MTU has to be discovered because of too big packets >>> and limited MTU capabilities on the path (happens also on tcp6 which works >>> thereofore not correctly). >>> >>> # From an internal host on net fd00:1234:5678::/64 >>> ping6 -s 2000 2a02:1234:5678:7::2 >>> >>> /etc/shorewall6/masq >>> EXT_IF fc00::/7 >>> >>> ip6tables rule: >>> MASQUERADE all * * fc00::/7 ::/0 >>> >>> # Internal interface >>> IP6 fd00:1234:5678::9 > 2a02:1234:5678:7::2: frag (0|1432) ICMP6, echo >>> request, seq 1, length 1432 >>> IP6 fd00:1234:5678::9 > 2a02:1234:5678:7::2: frag (1432|576) >>> IP6 2a02:1234:5678:9abc::115 > fd00:1234:5678::9: ICMP6, packet too big, >>> mtu 1440, length 1240 >>> >>> # External interface >>> IP6 2001:1234:5678:9abc::1 > 2a02:1234:5678:7::2: frag (0|1432) ICMP6, >>> echo request, seq 1, length 1432 >>> IP6 2001:1234:5678:9abc::1 > 2a02:1234:5678:7::2: frag (1432|576) >>> IP6 2a02:1234:5678:9abc::115 > 2001:1234:5678:9abc::1: ICMP6, packet too >>> big, mtu 1440, length 1240 >>> >>> Looks to me like a a major kernel bug. >>> Kernel version is: 4.1.3-201.fc22.x86_64 from Fedora 22 >>> >>> Any ideas? >>> >> Any comments? >> >> Ciao, >> Gerhard >> >> -- >> http://www.wiesinger.com/ >> >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> Please read the FAQ at http://www.tux.org/lkml/ > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ ^ permalink raw reply [flat|nested] 2+ messages in thread
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