Date: Mon, 20 Dec 2010 19:10:12 +0200 From: John Hay <jhay@meraka.org.za> To: Hiroki Sato <hrs@FreeBSD.org> Cc: jhay@FreeBSD.org, jhb@FreeBSD.org, freebsd-net@FreeBSD.org Subject: Re: IFT_L2VLAN and IPv6 link-local addresses Message-ID: <20101220171012.GB86149@zibbi.meraka.csir.co.za> In-Reply-To: <20101221.005458.144703395.hrs@allbsd.org> References: <20101220061057.GA36160@zibbi.meraka.csir.co.za> <201012200807.57670.jhb@freebsd.org> <20101221.005458.144703395.hrs@allbsd.org>
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Hi Hiroki,
On Tue, Dec 21, 2010 at 12:54:58AM +0900, Hiroki Sato wrote:
> John Baldwin <jhb@freebsd.org> wrote
> in <201012200807.57670.jhb@freebsd.org>:
>
> jh> On Monday, December 20, 2010 1:10:57 am John Hay wrote:
> jh> > Hi,
> jh> >
> jh> > I see that on FreeBSD-8 if you use IPv6 inside vlans, the local part of
> jh> > the address (bottom 64 bits) is based on the MAC address of the first
> jh> > ethernet interface on the system. It was not like this in my old -7,
> jh> > machine, so I looked around a bit. It looks like it is because vlans were
> jh> > changed to report their type as IFT_L2VLAN. So I made this patch to the
> jh> > IPv6 code that fix it for me:
> jh> >
> jh> > Index: sys/netinet6/in6_ifattach.c
> jh> > ===================================================================
> jh> > RCS file: /home/ncvs/src/sys/netinet6/in6_ifattach.c,v
> jh> > retrieving revision 1.74.2.3
> jh> > diff -u -U 5 -r1.74.2.3 in6_ifattach.c
> jh> > --- sys/netinet6/in6_ifattach.c 6 May 2010 06:44:19 -0000 1.74.2.3
> jh> > +++ sys/netinet6/in6_ifattach.c 15 Dec 2010 18:33:45 -0000
> jh> > @@ -265,10 +265,11 @@
> jh> > addrlen = sdl->sdl_alen;
> jh> >
> jh> > /* get EUI64 */
> jh> > switch (ifp->if_type) {
> jh> > case IFT_ETHER:
> jh> > + case IFT_L2VLAN:
> jh> > case IFT_FDDI:
> jh> > case IFT_ISO88025:
> jh> > case IFT_ATM:
> jh> > case IFT_IEEE1394:
> jh> > #ifdef IFT_IEEE80211
> jh> >
> jh> > Anything against me committing it? Am I missing something? Should it be
> jh> > sorted differently? Should it also be merged?
> jh>
> jh> This looks correct. Please fix and MFC. I haven't merged the kernel changes
> jh> to change the type of IFT_ for vlan's yet as I was worried about applications
> jh> such as this needing to be updated (such as dhcpd for example). I had thought
> jh> that I had not merged the kernel change to 8 though, that it was just in 9?
>
> Agreed with the fix, but I think both 7.X and 8.X pick the first IF's
> address anyway. Which log message did you get, "borrow interface
> identifier from..." or "...got interface identifier from itself"
> when net.inet6.icmp6.nd6_debug=1 on 7.X and 8.X, respectively?
You are correct. I forgot that in the 7.x network layout, the ipv6
networks were not in vlans. I just tried it on my old 7.2-PRE box:
sysctl net.inet6.icmp6.nd6_debug=1
ifconfig vlan0 create vlandev em2 vlan 1200
ifconfig vlan0 up
ifconfig vlan0
vlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
options=3<RXCSUM,TXCSUM>
ether 00:11:43:dc:fd:78
inet6 fe80::21b:21ff:fe13:2650%vlan0 prefixlen 64 tentative scopeid 0x6
media: Ethernet autoselect (1000baseTX <full-duplex>)
status: active
vlan: 1200 parent interface: em2
The last part of dmesg:
vlan0: borrow interface identifier from em0
vlan0: ifid: 02:1b:21:ff:fe:13:26:50
vlan0: starting DAD for fe80:6::21b:21ff:fe13:2650
vlan0: DAD complete for fe80:6::21b:21ff:fe13:2650 - no duplicates found
I also had a better look at if_vlan.c. John's IFT_L2VLAN changes has not
been merged, as he remembered. :-)
The line
ifp->if_type = IFT_L2VLAN;
has been there for a long time and his changes only change sdl->sdl_type
in any case.
John
--
John Hay -- jhay@meraka.csir.co.za / jhay@FreeBSD.org
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