From: Stephen Hemminger <shemminger@vyatta.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jesse Gross <jesse@nicira.com>,
davem@davemloft.net, netdev@vger.kernel.org
Subject: Re: [PATCH 3/3] vxlan: virtual extensible lan
Date: Thu, 4 Oct 2012 08:12:14 -0700 [thread overview]
Message-ID: <20121004081214.7f5a48fe@nehalam.linuxnetplumber.net> (raw)
In-Reply-To: <1349332490.16011.16.camel@edumazet-glaptop>
On Thu, 04 Oct 2012 08:34:50 +0200
Eric Dumazet <eric.dumazet@gmail.com> wrote:
> On Wed, 2012-10-03 at 21:02 -0700, Stephen Hemminger wrote:
>
> >
> > Since port is always a pair, there is no need to restrict range, unless
> > there was a broken firewall in the way. One bug there is that random32()
> > can return 0 which is not a valid port number. A better fallback
> > would be a hash of the MAC header.
>
> But using up to 65536 values for the port means that if vxlan traffic
> crosses a statefull firewall (eg netfilter with conntrack), this might
> need 65536 contexts/sessions.
This is UDP, there is no usable state to be found.
But as a practical matter it only needs to be wide enough to hit the
number of receive channels. Therefore even 64 is probably enough for
most people.
> So random32() is not needed.
>
> What might be needed is additional parameters for a vxlan tunnel, to
> give an optional range for the source port.
It could be per vxlan without a lot of pain. or just derive it value
from existing ephermeral port range.
next prev parent reply other threads:[~2012-10-04 15:12 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20121001223232.566037595@vyatta.com>
2012-10-01 22:32 ` [PATCH 1/3] netlink: add attributes to fdb interface Stephen Hemminger
2012-10-01 22:40 ` David Miller
2012-10-01 22:32 ` [PATCH 2/3] igmp: export symbol ip_mc_leave_group Stephen Hemminger
2012-10-01 22:40 ` David Miller
2012-10-01 22:32 ` [PATCH 3/3] vxlan: virtual extensible lan Stephen Hemminger
2012-10-01 22:40 ` David Miller
2012-10-04 1:54 ` Jesse Gross
2012-10-04 4:02 ` Stephen Hemminger
2012-10-04 6:34 ` Eric Dumazet
2012-10-04 15:12 ` Stephen Hemminger [this message]
2012-10-04 16:25 ` Jesse Gross
2012-10-04 4:39 ` [RFC] vxlan: use ether header as fallback hash Stephen Hemminger
2012-10-04 4:57 ` Eric Dumazet
2012-10-04 5:06 ` Stephen Hemminger
2012-10-04 16:27 ` Jesse Gross
2012-10-04 16:43 ` Stephen Hemminger
2012-10-04 17:06 ` Jesse Gross
2012-10-04 17:07 ` Eric Dumazet
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