[PATCH net] vxlan: use IANA assigned port

[PATCH net] vxlan: use IANA assigned port

[Stephen Hemminger]

Ken Duda of Arista Networks, one of the VXLAN RFC authors notified
me that IANA has assigned an official port for VXLAN. My initial version
of the driver used the value from CISCO LISP that was also being used by
OpenVswitch.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>


--- a/drivers/net/vxlan.c	2013-04-22 15:44:00.962002827 -0700
+++ b/drivers/net/vxlan.c	2013-04-26 16:29:19.349507680 -0700
@@ -8,7 +8,6 @@
  * published by the Free Software Foundation.
  *
  * TODO
- *  - use IANA UDP port number (when defined)
  *  - IPv6 (not in RFC)
  */
 
@@ -66,7 +65,7 @@ struct vxlanhdr {
 };
 
 /* UDP port for VXLAN traffic. */
-static unsigned int vxlan_port __read_mostly = 8472;
+static unsigned int vxlan_port __read_mostly = 4789;
 module_param_named(udp_port, vxlan_port, uint, 0444);
 MODULE_PARM_DESC(udp_port, "Destination UDP port");
 

Re: [PATCH net] vxlan: use IANA assigned port

[David Miller]

From: Stephen Hemminger <stephen@networkplumber.org>
Date: Fri, 26 Apr 2013 16:33:46 -0700

> Ken Duda of Arista Networks, one of the VXLAN RFC authors notified
> me that IANA has assigned an official port for VXLAN. My initial version
> of the driver used the value from CISCO LISP that was also being used by
> OpenVswitch.
> 
> Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>

So how does this interact with already deployed VXLAN links?

What is the backwards compatability story?  What if one node upgrades
with this patch installed, but all the other nodes are left using
the older port number by default?

Re: [PATCH net] vxlan: use IANA assigned port

[Chris Wright]

* David Miller (davem@davemloft.net) wrote:
> From: Stephen Hemminger <stephen@networkplumber.org>
> Date: Fri, 26 Apr 2013 16:33:46 -0700
> 
> > Ken Duda of Arista Networks, one of the VXLAN RFC authors notified
> > me that IANA has assigned an official port for VXLAN. My initial version
> > of the driver used the value from CISCO LISP that was also being used by
> > OpenVswitch.
> > 
> > Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
> 
> So how does this interact with already deployed VXLAN links?
> 
> What is the backwards compatability story?  What if one node upgrades
> with this patch installed, but all the other nodes are left using
> the older port number by default?

With this patch, I think one node upgrading would need to override
the default vxlan_port module param (falling back to the pre IANA
default) to keep active with the existing overlays.

Re: [PATCH net] vxlan: use IANA assigned port

[David Miller]

From: Chris Wright <chrisw@sous-sol.org>
Date: Fri, 26 Apr 2013 18:51:29 -0700

> * David Miller (davem@davemloft.net) wrote:
>> From: Stephen Hemminger <stephen@networkplumber.org>
>> Date: Fri, 26 Apr 2013 16:33:46 -0700
>> 
>> > Ken Duda of Arista Networks, one of the VXLAN RFC authors notified
>> > me that IANA has assigned an official port for VXLAN. My initial version
>> > of the driver used the value from CISCO LISP that was also being used by
>> > OpenVswitch.
>> > 
>> > Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
>> 
>> So how does this interact with already deployed VXLAN links?
>> 
>> What is the backwards compatability story?  What if one node upgrades
>> with this patch installed, but all the other nodes are left using
>> the older port number by default?
> 
> With this patch, I think one node upgrading would need to override
> the default vxlan_port module param (falling back to the pre IANA
> default) to keep active with the existing overlays.

That's an unacceptable burdon for our users.

We're stuck with the initial port number you've choosen.

People can override to the "official" port if they want to.

Re: [PATCH net] vxlan: use IANA assigned port

[David Miller]

From: Stephen Hemminger <stephen@networkplumber.org>
Date: Fri, 26 Apr 2013 21:53:59 -0700

> The port should be a property anyway.
> That way the value is easier to control. And we can do the transistion
> there.

Works for me.