[Babel-users] preferred source address vs babel

[Juliusz Chroboczek]

> The packets never traverse the 2a02-network yet it is showing up in the
> traceroute and that way the 2a02 addresses are leaking into the mesh
> revealing information about the node that should not be revealed.
> Sacondly packets originating from the node like DNS may leave the node
> with an inappropriate ipv6 address and could possibly be routed out
> through the wan interface of the node.

I understand what you're trying to do.  I want to understand why.

Which interface is the address in 2a02 installed on?  If it's a different
interface, then according to RFC 6724 Section 5 rule 5, the other address
should be chosen.  If the address is installed on the same interface, then
I'd like to understand why.

>> I have no objection (and I'd be glad to apply a well-written patch that
>> does that), but I don't think this should be necessary.

> I opened a PR for this

https://github.com/jech/babeld/pull/15

As I've said there, I don't think it should be a command-line option -- it
should live in the configuration file.  If people want to put it on the
command-line, they should be using "-C".

What's more, I don't think it makes sense for it to be a global option,
since with multiple interfaces you don't usually want to use the same
address with all interfaces.  I can see the following:

  - it could be an interface option, in which case it would apply to all
    routes going out through that interface;
  - it could be a filter option, in which case it would apply to matching
    routes.

Perhaps the list could chime in?

-- Juliusz