netdev - Re: (usagi-users 04056) Re: ping6 is sent out from wrong interface

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 26 Jun 2008 09:48:26 +0900
From:	Naohiro Ooiwa <nooiwa@...aclelinux.com>
To:	Fey Marcus <Fey@...g.de>
CC:	usagi-users@...linux-ipv6.org,
	YOSHIFUJI Hideaki / 吉藤英明 
	<yoshfuji@...ux-ipv6.org>, netdev@...r.kernel.org,
	usagi-users@...ux-ipv6.org
Subject: Re: (usagi-users 04056) Re: ping6 is sent out from wrong interface

Hi Marcus

Thank you for your comment.

>>
>> Thank you for your quick reply.
>>
>>> It's due to routing.
>> For the reason of selecting 'eth0', I agree.
>> But, I think the device is specified before looking up the 
>> routing table in this case.
> 
> Well, ping's man page reads: 
> ---
>        -I interface address
>               Set source address to specified interface  address.  Argument
>               may  be  numeric  IP  address or name of device. When pinging
>               IPv6 link-local address this option is required.
> ---
> 
> So you only set the address, not the interface to be used for sending.

Then, the man page doesn't match with the implementation.

> 
>>> ...with eth0 being preferred over eth1 for multicast packets.
>>> You could add a dedicated route for ff02::/16 to make the 
>> kernel output the packet via eth1.
>>
>> This works when using only "eth1" for multicasts.
>> When multiple I/Fs are connected to separate networks, this 
>> scheme requires changing the route every time a user need to 
>> send ping to different network.
>>
> 
> Ok, my proposition was a bit too general. It would probably be better to set up routes for the exact addresses. So in your case to ff02::1. 
> 
> Of course, if you wish to send the same packet via several interfaces within a short time, this would still result in adding and deleting the routes over and over again.
> 
>> I think kernel can solve this problem better.
>>
> 
> I don't think this would be intended....
> 

I was just confused by the difference of
source address things between IPv4 and IPv6.

Regards,
Naohiro Ooiwa


--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html