Subject: Re: ipv6 secondary ips and default ipv6 ip for new outbound connections

From: Brian Haley <[email-masked]>
Date: Mon, 21 Mar 2011 22:14:39 -0400

On 03/18/2011 11:35 PM, Jim Westfall wrote:
> Brian Haley <[email-masked]> wrote [03.18.11]:
>> On 03/18/2011 07:03 PM, Jim Westfall wrote:
>>> Hi
>>>
>>> On ipv4 the first ip added to a nic will be used as the source ip for 
>>> new outbound connections.  Any additional ips, in the same netblock, 
>>> will be added as secondaries.
>>>
>>> ipv6 seems to have the opposite behavior.  The last ipv6 ip added to a 
>>> nic is be used for new outbound connections.

<snip>

>> According to commit 8a6ce0c083f5736e90dabe6d8ce077e7dd0fa35f it's done this
>> way for backward-compatibility - we used to always put new addresses at the
>> front, then we started sorting them by scope.  I couldn't find in the archives
>> who needed the backward-compatible behavior (it was way back in 2006), but
>> Yoshifuji proposed it and I Acked it.
>>
>> You could see if this patch helps you out, but I'm not sure if changing this
>> would break someone else, you'd have to see about putting a knob to control
>> this.
>>
>> -Brian
>>
>> diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
>> index 3daaf3c..8c7d5a5 100644
>> --- a/net/ipv6/addrconf.c
>> +++ b/net/ipv6/addrconf.c
>> @@ -577,7 +577,7 @@ ipv6_link_dev_addr(struct inet6_dev *idev, struct inet6_ifaddr *ifp)
>>  	list_for_each(p, &idev->addr_list) {
>>  		struct inet6_ifaddr *ifa
>>  			= list_entry(p, struct inet6_ifaddr, if_list);
>> -		if (ifp_scope >= ipv6_addr_src_scope(&ifa->addr))
>> +		if (ifp_scope > ipv6_addr_src_scope(&ifa->addr))
>>  			break;
>>  	}
>>  
> 
> Hi
> 
> Your patch fixes it for me.

Then we need to get Yoshifuji to Ack it since he wanted the previous behavior of
newest-added being first.

-Brian