v6-only SSID issue

[furry13@…]

Hi guys,

I'm seeing SLAAC issues on v6-only SSID (around lobby area):

furry@Wintermute:~>ifconfig en0
en0: flags=8963<UP,BROADCAST,SMART,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500
    ether 68:a8:6d:12:f7:b2
    inet6 fe80::6aa8:6dff:fe12:f7b2%en0 prefixlen 64 scopeid 0x4
    inet 169.254.107.89 netmask 0xffff0000 broadcast 169.254.255.255
    nd6 options=1<PERFORMNUD>
    media: autoselect
    status: active

Looks like my machine is sending RSes but not getting anything back
(see two captures attached). After a while it stars working...but then
gets broken again..etc..

My MAC address: 68:a8:6d:12:f7:b2
OS: 10.9.4
Location: lobby

-- 
SY, Jen Linkova aka Furry

slaac​

slaac_issue.pcap​

[furry13@…]

Added by email2trac

[furry13@…]

Added by email2trac

[furry13@…]

It looks to me like multicast RAs are getting dropped while being
transmitted over air:


furry@Wintermute:~>sudo tcpdump -i en0 -n  'icmp6'
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on en0, link-type EN10MB (Ethernet), capture size 65535 bytes
17:41:20.964597 IP6 fe80::6aa8:6dff:fe12:f7b2 > ff02::2: ICMP6, router
solicitation, length 16
^^^^^^ - here I ran rtsol en0

17:41:24.965505 IP6 fe80::6aa8:6dff:fe12:f7b2 > ff02::2: ICMP6, router
solicitation, length 16
17:41:28.966506 IP6 fe80::6aa8:6dff:fe12:f7b2 > ff02::2: ICMP6, router
solicitation, length 16
17:41:37.480199 IP6 fe80::6aa8:6dff:fe12:f7b2 > ff02::2: ICMP6, router
solicitation, length 16

17:41:37.541858 IP6 fe80::999:1 > ff02::1: ICMP6, router
advertisement, length 56
^^^^ ...and here an RA came...


On Mon, Jul 21, 2014 at 12:57 PM, IETF Meeting/NOC
<tickets@meeting.ietf.org> wrote:
> #741: v6-only SSID issue
> ----------------------------+---------------------------------
>       Reporter:  furry13@…  |                Owner:  nkukich@…
>           Type:  defect     |               Status:  assigned
>       Priority:  tbd        |            Milestone:  ietf-90
>      Component:  network    |           Resolution:
>       Keywords:             |  My Current Location:
> My MAC  Address:            |                My OS:
> ----------------------------+---------------------------------
> Changes (by llynch@…):
>
>  * owner:  llynch@… => nkukich@…
>  * status:  new => assigned
>  * component:  incoming => network
>  * type:  request => defect
>
>
> --
> Ticket URL: <https://tickets.meeting.ietf.org/ticket/741#comment:1>
> IETF Meeting/NOC <https://tickets.meeting.ietf.org>
> IETF Meeting - NOC pages



-- 
SY, Jen Linkova aka Furry

[anonymous]

We have seen something like this in the past; if you get into a state where you do not see RAs, can you bounce your radio and see if upon re-assoc everything is fine again?

Also I am assuming this is a MAC running some version of OSX?

[furry13@…]

On Mon, Jul 21, 2014 at 7:20 PM, IETF Meeting/NOC
<tickets@meeting.ietf.org> wrote:
> #741: v6-only SSID issue
> ----------------------------+---------------------------------
>       Reporter:  furry13@…  |                Owner:  nkukich@…
>           Type:  defect     |               Status:  assigned
>       Priority:  tbd        |            Milestone:  ietf-90
>      Component:  network    |           Resolution:
>       Keywords:             |  My Current Location:
> My MAC  Address:            |                My OS:
> ----------------------------+---------------------------------
>
> Comment (by anonymous):
>
>  We have seen something like this in the past; if you get into a state
>  where you do not see RAs, can you bounce your radio and see if upon re-
>  assoc everything is fine again?

I tried this, it worked at least in some cases - most likely because
my box sends RS upon re-association.

>  Also I am assuming this is a MAC running some version of OSX?

My MAC address: 68:a8:6d:12:f7:b2
 OS: 10.9.4


-- 
SY, Jen Linkova aka Furry

[furry13@…]

On Mon, Jul 21, 2014 at 7:44 PM, Jen Linkova <furry13@gmail.com> wrote:
>>  We have seen something like this in the past; if you get into a state
>>  where you do not see RAs, can you bounce your radio and see if upon re-
>>  assoc everything is fine again?
>
> I tried this, it worked at least in some cases - most likely because
> my box sends RS upon re-association.

Sometimes re-association helps. However sometimes it does not unless I
keep trying. ~1 hr ago I had to turn wifi off/on 3 times before I
finally got an RA - so 9 RSes had to be sent..
The most recent example:

furry@Wintermute:~/tmp/IETF90>sudo tcpdump -i en0 -n  'icmp6 and
(ip6[40] = 133 or ip6[40] = 134)'
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on en0, link-type EN10MB (Ethernet), capture size 65535 bytes
22:52:14.766178 IP6 fe80::479:9050:2171:f944 > ff02::2: ICMP6, router
solicitation, length 16
22:54:25.992622 IP6 fe80::999:1 > ff02::1: ICMP6, router
advertisement, length 56
22:58:43.195209 IP6 fe80::999:1 > ff02::1: ICMP6, router
advertisement, length 56
23:00:28.278570 IP6 fe80::999:1 > ff02::1: ICMP6, router
advertisement, length 56
23:10:21.539429 IP6 fe80::2677:3ff:fe75:dea4 > ff02::2: ICMP6, router
solicitation, length 16
23:14:26.759095 IP6 fe80::6aa8:6dff:fe12:f7b2 > ff02::2: ICMP6, router
solicitation, length 8
23:14:31.547015 IP6 fe80::6aa8:6dff:fe12:f7b2 > ff02::2: ICMP6, router
solicitation, length 16
23:14:36.274317 IP6 fe80::6aa8:6dff:fe12:f7b2 > ff02::2: ICMP6, router
solicitation, length 16

....ok, 30 mins after the last RA - I don't have IP address anymore.
So I'm turning wifi off anf on again:

23:32:27.569614 IP6 fe80::6aa8:6dff:fe12:f7b2 > ff02::2: ICMP6, router
solicitation, length 8
23:32:32.412634 IP6 fe80::6aa8:6dff:fe12:f7b2 > ff02::2: ICMP6, router
solicitation, length 16
23:32:36.832145 IP6 fe80::6aa8:6dff:fe12:f7b2 > ff02::2: ICMP6, router
solicitation, length 16

...still nothing but 3 mins later RA finally came..

23:35:22.913614 IP6 fe80::999:1 > ff02::1: ICMP6, router
advertisement, length 56

I could not say I'm surprised as I was observing 1-2 sec RTT to the
first hop...so many packets die on the air and multicasts are
particularly vulnerable...But just in case you need some users reports
about the issue....

-- 
SY, Jen Linkova aka Furry

[Rick Alfvin]

Milestone renamed