[ovs-discuss] GRE over IPv6 configuration

[Eli Britstein]

On 6/4/2019 8:24 PM, Ben Pfaff wrote:
> On Tue, Jun 04, 2019 at 03:13:02PM +0000, Eli Britstein wrote:
>> Hello,
>>
>> I would like to configure a GRE tunnel over IPv6, on a Linux system.
>> However, I encounter the following:
>>
>> My command:
>> ovs-vsctl add-port br1 gre6 -- set interface gre6 type=ip6gre
>> options:remote_ip= 2001:db8:0:f102::11 options:key=55
>>
>> Output:
>> ovs-vsctl: Error detected while setting up 'gre6': could not add network
>> device gre6 to ofproto (Address family not supported by protocol).  See
>> ovs-vswitchd log for details.
>> ovs-vsctl: The default log directory is "/var/log/openvswitch".
>>
>> In the log:
>> bridge|WARN|could not add network device gre6 to ofproto (Address family
>> not supported by protocol)
>>
>> I notice that if I want to define a ip6gretap with “ip link”, there is a
>> need to use “-6” option, to set the correct family.
>>
>> Is there a way to note the correct family (though I think should be
>> implicit by “ip6gre”)? Or maybe some other configuration?
> OVS doesn't have an "ip6gre" interface type.  Just use "gre".

I see it does in lib/netdev-vport.c, line 1222. Isn't that ip6gre?

Anyway, indeed trying with just "gre" the configuration passes OK. 
However, I don't see any traffic on the other machine.

         Port "gre6"
             Interface "gre6"
                 type: gre
                 options: {key="55", local_ip="2001:db8:0:f102::f0", 
remote_ip="2001:db8:0:f102::f1"}

$ ping 2001:db8:0:f102::f1
PING 2001:db8:0:f102::f1(2001:db8:0:f102::f1) 56 data bytes
64 bytes from 2001:db8:0:f102::f1: icmp_seq=1 ttl=64 time=0.440 ms
64 bytes from 2001:db8:0:f102::f1: icmp_seq=2 ttl=64 time=0.072 ms

I even configured an explicit OF rule to redirect to the gre6 port. I 
see it is hit, but still no traffic.

Do I have to configure explicit routes or something of that kind?