Re: ipv6: default route for link local address is not added while assigning a address

On Friday 10 January 2014 10:46 PM, Hannes Frederic Sowa wrote:

On Fri, Jan 10, 2014 at 05:33:08PM +0100, Nicolas Dichtel wrote:

quoted

CC: netdev

Le 10/01/2014 13:20, sohny thomas a écrit :

quoted

Default route for link local address is configured automatically if
NETWORKING_IPV6=yes is in ifcfg-eth*.
When the route table for the interface is flushed and a new address is
added to
the same device with out removing linklocal addr, default route for link
local
address has to added by default.

I would say that removing the link local route but not the link local
address
is a configuration problem.
If you remove a connected route but not the associated address, you will
have
the same problem.

We have some user accessible routes that are essential for IPv6 stack
to work at all. So I don't know if I can agree with that.

Maybe flush is a bit too aggressive?

Hi ,

Thank you for the inputs.

In the test for ipv6 default address selection , we are testing the rule
2 as specified in RFC 6724

   If Scope(SA) < Scope(SB): If Scope(SA) < Scope(D), then prefer SB
     and otherwise prefer SA.
     Similarly, if Scope(SB) < Scope(SA): If Scope(SB) < Scope(D), then
     prefer SA and otherwise prefer SB.

Test:

   Check 04:
      Destination: ff08::2(OS)
      Candidate Source Addresses: fec0::1(SS) or LLA(LS)
      Result: fec0::1(SS)

      Scope(LLA) < Scope(fec0::1): If Scope(LLA) < Scope(ff08::2),  yes, 
prefer fec0::1


Now in the test its flushing all the routes and adding an address ,
which in causes to add route into the routing table including the link
local routes.
Earlier in 2.6.32 it used to work fine now due to the above mentioned
check-in this is not happening

Of course we can still just delete a route and add , but even if we
delete the link local route, IMHO i think it should update the LLA route
when the interface is next added an address or bought up which ever is
the case.

Regards,
Sohny