[Babel-users] atomic updates and ipv6 cache flushing issues

[Dave Taht]

On Sun, May 5, 2013 at 5:57 AM, Leen Besselink <leen at consolejunkie.net> wrote:
> On Sun, May 05, 2013 at 05:11:26AM -0700, Dave Taht wrote:
>> Robert bradley has been working on making atomic route updates work
>> and possibly better route cache flushing.
>>
>> His current branch merges just fine with babeld head, and has tested
>> it on 3.5, 3.7 and 3.8, but I have not tested it thoroughly yet
>> myself.
>>
>> get the patchset from: git://github.com/rb12345/babeld.git
>>
>>
>
> Hi,
>
> I've been watching from a far what Babel has been doing and I find it all very interresting.
>
> Also I have some test VMs I'm running to see how Babel works and seen this bahaviour as well.
>
> I hope to find the time to give this code a try.
>
> My questions are some what related:
>
> Now that Linux 3.8 has support for IPv6 ECMP is there any plan to use that again to make updates
> more attomic or even support multipath directly. Because that is what I've been interrested in.
>
> If I remember correctly Dave Täht also mentioned he would like to see someone implement it.

It's not ECMP for ipv6 I'm looking to see solved for multiple routing
protocols, but the multiple ipv6 prefixes/multiple exits source
routing problem. Take the case where you have one network but two
gateways.

GW A                                  GW B
2001:db8:2::1/48                   2001:db8:1::1/48
         |                                        |
        --your-hosts-on-your-network--

Both gateways distribute both prefixes to all clients, so they have
their choice of prefix to use for any given connection attempt.

Solving for a single default gw in a routing protocol in this case
won't work, as packets sourced from 2001:db8:1:X won't go out
2001:db8:2:X and vice versa.

The homenet folk demonstrated this form of ipv6 multihoming working
(using a version of OSPF and BIRD, I believe) at the last ietf. It was
very cool (to me at least) to see openwrt used in all three of the
bits and bytes demos.

http://www.ietf.org/blog/2013/04/bits-n-bytes-on-video/

-- 
Dave Täht

Fixing bufferbloat with cerowrt: http://www.teklibre.com/cerowrt/subscribe.html