Subject: Re: [RFC PATCH net-next 1/1] ipv6: add support of ECMP

From: Nicolas Dichtel <[email-masked]>
Date: Wed, 12 Sep 2012 11:53:51 +0200

Le 12/09/2012 11:42, YOSHIFUJI Hideaki a écrit :
> Hello.
> 
> YOSHIFUJI Hideaki wrote:
>> Hello.
>>
>> Nicolas Dichtel wrote:
>>> This patch adds the support of equal cost multipath for IPv6.
>>>
>>> The patch is based on a previous work from
>>> Luc Saillard <[email-masked]>.
>>>
>>> Signed-off-by: Nicolas Dichtel <[email-masked]>
>> :
>>> +config IPV6_MULTIPATH
>>> +	bool "IPv6: equal cost multipath for IPv6 routing"
>>> +	depends on IPV6
>>> +	default y
>>> +	---help---
>>> +	  Enable this option to support ECMP for IPv6.
>>> +	  If unsure, say N.
>>> +
>>> +choice
>>> +	prompt "IPv6: choose Multipath algorithm"
>>> +	depends on IPV6_MULTIPATH
>>> +	default IPV6_MULTIPATH_ROUTE
>>> +	---help---
>>> +	  Define the method to select route between each possible path.
>>> +
>>> +	config IPV6_MULTIPATH_ROUTE
>>> +	bool "IPv6: MULTIPATH flow algorithm"
>>> +	---help---
>>> +	  Multipath routes are chosen according to hash of packet header to
>>> +	  ensure a flow keeps the same route.
>>> +
>>> +	config IPV6_MULTIPATH_RR
>>> +	bool "IPv6: MULTIPATH round robin algorithm"
>>> +	---help---
>>> +	  Multipath routes are chosen according to Round Robin.
>>> +
>>> +	config IPV6_MULTIPATH_RANDOM
>>> +	bool "IPv6: MULTIPATH random algorithm"
>>> +	---help---
>>> +	  Multipath routes are chosen in a random fashion.
>>> +endchoice
>>
>> We should use hash-based algorithm by default,
>> according to RFC4311.  See also RFC6438.
> 
> Sorry, I missed something and misunderstood.
> 
> 
> I prefer "HASH" of "FLOW" instead of "ROUTE"
> because it select route by "hash" or "flow"
> (as other options mean; by "round-robin"(RR) or by "random"(RANDOM)).
Ok.

> 
> And, please clearly specify that it is the recommended
> the default and recommended algorithm.
> (We may have references to RFCs.)
Ok.

> 
> Default is "y" but description says "if unsure, say N."
> This is not good.
Yes, good catch.

> 
> 
> Of course, we may want to take "flow label" into account
> when calculating hash (RFC6438).
Ok, I will add it. I wait for others comments.

Regards,
Nicolas