ipsec: add ipv6 support for ipsec tunnel interface

Change-Id: I6a76907dc7bed2a81282b63669bea2219d6903c9
Signed-off-by: Kingwel Xie <kingwel.xie@ericsson.com>
Signed-off-by: Neale Ranns <neale.ranns@cisco.com>
diff --git a/src/vnet/ipsec/ipsec_cli.c b/src/vnet/ipsec/ipsec_cli.c
index 2020e79..0f47c7b 100644
--- a/src/vnet/ipsec/ipsec_cli.c
+++ b/src/vnet/ipsec/ipsec_cli.c
@@ -721,12 +721,11 @@
       goto done;
     }
 
-  if (ipv6_set)
-    return clib_error_return (0, "currently only IPv4 supported");
-
   if (ipv4_set && ipv6_set)
     return clib_error_return (0, "both IPv4 and IPv6 addresses specified");
 
+  a.is_ip6 = ipv6_set;
+
   clib_memcpy (a.local_crypto_key, lck.data, lck.len);
   a.local_crypto_key_len = lck.len;
   clib_memcpy (a.remote_crypto_key, rck.data, rck.len);