[Babel-users] Sroamd: Protocol Documentation?

[Nick]

Okay, I found this design description that is very helpful. :)
https://www.mail-archive.com/babel-users@alioth-lists.debian.net/msg00662.html

> Design
> ======
>
> Every sroamd node acts as a WiFi AP, as DHCPv4 server and as an IPv6 RA
> server.  There is a replicated database, flooded between all sroamd nodes,
> that contains, for each mobile node:
>
>    - the IPv4 address it has been assigned;
>    - the IPv6 prefix that it has been assigned;
>    - its current location.
>
> This information is used to announce a route to the mobile node over
> Babel, which ensures that traffic destined to the mobile client gets to
> it.  Traffic from the mobile node, on the other hand, is routed using
> a simple hack (idea stolen from PMIPv4): all the sroamd nodes have the
> same IPv4 address, the same link-local IPv6 address; a gratuitious ARP and
> ND is sent to each node as soon as it associates to an AP in order to
> update its neighbour tables tables.
>
> Interestingly, the algorithm is intrinsically racy: agreeing on the mobile
> node's location is a distributed consensus problem, and therefore
> theoretically impossible.  In other words, in the absence of a global
> clock the nodes sroamd nodes might, occasionally, disagree on the location
> of a mobile node.  We solve this issue by detecting this situation (grep
> for "conflict" in flood.c), and pinging the node at both locations.  Note
> that I haven't proved the algorithm correct, so there might be some edge
> cases I haven't thought about.

On 7/20/21 11:00 AM, Nick wrote:
> Hi,
> is there protocol documentation on how sroamd works? I looked into the 
> README.md but the text was rather short.
>
> Bests,
> Nick
>
>
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