Some years ago Christopher wrote two posts
(2016,
2015)
about the IPv6-related characteristics of the WiFi network at Cisco Live
Europe. To somewhat continue this tradition and for mere technical interest I
had a look at some properties of this year’s setting.
There were two SSIDs of interest: a dual-stacked one (“CiscoLive2019”) and one
with v6-only plus NAT64 (“CL-NAT64”). For some background on the underlying
infrastructure components you might look at this
thread
by Nicolas Darchis from the NOC or
at this tweet
from Dominik Pickhardt. Some stats on
IPv6 usage at CLEUR can be
found here.
Enno and I spent the first day on Cisco Live Europe in Berlin today attending
the “Advanced Practical Knowledge for Enterprise Deploying IPv6” technical
breakout held by Tim Martin and
Jim Bailey.
It was a good breakout session, and thanks again Tim for the honorable mention
of our work in your slides! We really appreciate it. Like
last year,
we were curious how the Wifi network was setup this year as I face a
corresponding task for Troopers in March,
with some
major changes
in comparison to the last years. The Wifi infastructure in Berlin looked very
similar to the one from last year in Milan, we had the “standard” Cisco Live
SSID as well as an IPv6-only (with NAT64 as translation mechanism) SSID. The
standard SSID looked identical to last year with the exception that now the
RA Throttling
feature on the WLC was active from the beginning! Neither the M nor the O flag
are set which means that my client has to use the legacy protocol to resolve
AAAA records. As I am running Windows, it does not support
RA option 25 but the option wasn’t
included in the RAs anyway. The preference was configured to the default
“medium”. One thing I noticed, but haven’t had a chance to ask
Andrew Yourtchenko, was that for the legacy
(IPv4) connection they use HSRPv2 as an FHRP protocol (indicated by the MAC
address
00:00:0c:9f:f0:01
I received from the gateway) but for IPv6 I received Router Advertisements from
two different MAC addresses (which both belong to Cisco, so I don’t think anyone
sent spoofed RAs). I am curious about the reasoning for this approach 🙂
What i also encountered was that the Peer-to-Peer Blocking feature was
apparently not enabled on the SSID as I was able to enumerate approx. 1600
active clients at the time. No worries, I haven’t done anything else, just was
curious whether the feature was activated or not…
Given that Enno and I are network geeks, and that I am responsible for setting
up the Troopers Wifi network I was curious
which components might be used at Cisco Live and which IPv6 related
configuration was done for the Wifi network to ensure a reliable network and
reduce the chatty nature of IPv6. Andrew Yourtchenko
(@ayourtch) already did an amazing job last year
at Cisco Live Europe explaining in detail (at the time
session BRKEWN-2666) the
intricacies of IPv6 in Wifi networks, and how to optimize IPv6 for these
networks. He was also a great inspiration for me when setting up the
Troopers Wifi network
a couple of weeks later. Thank You!