Merge pull request #1163 from remibergsma/arping-to-gw

Send arping to the gateway instead of our own addressWe need to send an Unsolicited ARP to the gateway, instead of our own address. We now encounter problems when people deploy/destroy/deploy and get the same public ip.

Packets arrive, but with incorrect / cached mac and are ignored by the routervm kernel.
Run arping manually to update the arp-cache on the gateway and things start to work.

Then we discovered the `arping` is actually done, but sent to its own address. Therefore the gateway doesn't pick it up. We only saw this happening when rapid deploy tools are used, like Terraform that do deploy/destroy/deploy and might get the same ip but on a new router having a new mac.

```
2015-12-03 18:07:25,589  CsHelper.py execute:160 Executing: arping -c 1 -I eth1 -A -U -s 192.168.23.8 192.168.23.1
```

The integration tests seem happy, although the full run is still ongoing:

```
=== TestName: test_01_create_redundant_VPC_2tiers_4VMs_4IPs_4PF_ACL | Status : SUCCESS ===
```

Thanks @sspans for helping trouble shoot this. Ping @wilderrodrigues can you review please?

* pr/1163:
  CLOUDSTACK-9097 Make public ip work immediately

Signed-off-by: Remi Bergsma <github@remi.nl>

systemvm/patches/debian/config/opt/cloud/bin/cs/CsAddress.py

@@ -588,7 +588,7 @@ class CsIP:
 
     def arpPing(self):
         cmd = "arping -c 1 -I %s -A -U -s %s %s" % (
-            self.dev, self.address['public_ip'], self.address['public_ip'])
+            self.dev, self.address['public_ip'], self.address['gateway'])
         CsHelper.execute(cmd)
 
     # Delete any ips that are configured but not in the bag