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Set up Apache2 web server on two instances with shared ip

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This article describes how to run an Apache2 web server on a pair of cloud servers with a
shared public IPv4 IP address. The shared IP address ensures that users of services don't
need to change addresses when the second server seamlessly takes over from the first after
the first server goes down.

The use case in this article shows an Apache web server deployed on two
cloud servers running the Ubuntu operating system with a shared IP address on
PublicNet that is used to reach the web servers. A heartbeat is used as the
protocol to determine which cloud server is currently the owner of the
shared IP address and will respond to a web request.

The following sections show you how to:

  • Create two servers in the same publicIPZoneId

  • Create a shared IP address and associate the shared IP address
    with both servers

  • Configure apache2 and set up the heartbeat on the servers

  • Test the configuration

Before you begin

You should have an authentication token and the ability to use cURL in your environment.

Create two servers in the same publicIPZoneId

Perform the following steps from your local computer.

  1. Boot the primary server. Save the server ID for future reference.

    Request:

     curl -s https://dfw.servers.api.rackspacecloud.com/v2/5831008/servers
    -X POST -H "Content-Type: application/json"
    -H "X-Auth-Token: $token"
    -d " {"server": {"name": "isol1", "imageRef": "adb78bf4-81ae-4dce-a417-8eb2b7f7f0c3", "flavorRef": "2", "max_count": 1, "min_count": 1, "networks": [{"uuid": "00000000-0000-0000-0000-000000000000"}, {"uuid": "11111111-1111-1111-1111-111111111111"}, {"uuid": "7af32f1c-85de-44c5-be68-4b1465566683"}]}}"

    Response:

     {"server": {
     "OS-DCF:diskConfig": "AUTO",
     "id": "96bbd712-0f64-4146-bfb2-b2bd91f20319",
     "links": [
        {"href": "https://dfw.servers.api.rackspacecloud.com/v2/5831008/servers/96bbd712-0f64-4146-bfb2-b2bd91f20319", "rel": "self"},
        {"href": "https://dfw.servers.api.rackspacecloud.com/5831008/servers/96bbd712-0f64-4146-bfb2-b2bd91f20319", "rel": "bookmark"}
     ],
     "adminPass": "P6dW6YLk4pLQ"
  }
 }

  2. Get the details for the primary server. Save the publicIPZoneId for future
    reference.

    Request:

     curl -s https://dfw.servers.api.rackspacecloud.com/v2/5831008/servers/96bbd712-0f64-4146-bfb2-b2bd91f20319
    -X GET -H "Content-Type: application/json"
    -H "X-Auth-Token: $token"

    Response:

     {"server": {
     "OS-DCF:diskConfig": "AUTO",
     "OS-EXT-STS:power_state": 1,
     "OS-EXT-STS:task_state": null,
     "OS-EXT-STS:vm_state": "active",
     "RAX-PUBLIC-IP-ZONE-ID:publicIPZoneId": "8487ac8920752e042b0c70a4f9e064157ed2e051728fe2beb6bff09f",
     "accessIPv4": "10.23.233.113",
     "accessIPv6": "2001:4801:787f:205:a8bb:ccff:fe00:108",
     "addresses": {
        "private": [
           {"addr": "10.183.232.104","version": 4}
        ],
        "public": [
           {"addr": "10.23.233.113","version": 4},
           {"addr": "2001:4801:787f:205:a8bb:ccff:fe00:108","version": 6}
        ]
     },
     "config_drive": "",
     "created": "2015-07-27T20:02:48Z",
     "flavor": {
        "id": "2",
        "links": [
           {"href": "https://dfw.servers.api.rackspacecloud.com/5831008/flavors/2","rel": "bookmark"}
        ]
     },
     "hostId": "e8eec5e7fca548316dc32ac57010fbb23e035088c4625e4e92804e52",
     "id": "96bbd712-0f64-4146-bfb2-b2bd91f20319",
     "image": {
        "id": "adb78bf4-81ae-4dce-a417-8eb2b7f7f0c3",
        "links": [
           {"href": "https://dfw.servers.api.rackspacecloud.com/5831008/images/adb78bf4-81ae-4dce-a417-8eb2b7f7f0c3","rel": "bookmark"}
        ]
     },
     "key_name": null,
     "links": [
        {"href": "https://dfw.servers.api.rackspacecloud.com/v2/5831008/servers/96bbd712-0f64-4146-bfb2-b2bd91f20319","rel": "self"},
        {"href": "https://dfw.servers.api.rackspacecloud.com/5831008/servers/96bbd712-0f64-4146-bfb2-b2bd91f20319","rel": "bookmark"}
     ],
     "metadata": {},
     "name": "isol1",
     "progress": 100,
     "status": "ACTIVE",
     "tenant_id": "5831008",
     "updated": "2015-07-27T20:03:46Z",
     "user_id": "207638"
  }

    }

  3. Boot the replica server in same publicIPZoneId as the primary server by using
    a scheduler hint. Save the server ID for future reference.

    Request:

     curl -vv -s -k https://dfw.servers.api.rackspacecloud.com/v2/5831008/servers
    -X POST -H "Content-Type: application/json"
    -H "X-Auth-Token: $token"
    -d "{"server":{"name": "isol2","imageRef": "adb78bf4-81ae-4dce-a417-8eb2b7f7f0c3","os:scheduler_hints": {"public_ip_zone:near":
      ["96bbd712-0f64-4146-bfb2-b2bd91f20319"]
    },
    "flavorRef": "2",
    "max_count": 1,
    "min_count": 1,
    "networks":
      [
        {"uuid": "00000000-0000-0000-0000-000000000000"
        },
        {"uuid": "11111111-1111-1111-1111-111111111111"
        },
        {"uuid": "7af32f1c-85de-44c5-be68-4b1465566683"
        }
       ]
     }
   }”

    Response:

     {"server": {
     "OS-DCF:diskConfig": "AUTO",
     "id": "ffec9d55-2d54-4718-bc3a-0d47fb8c52c1",
     "links": [
        {"href": "https://dfw.servers.api.rackspacecloud.com/v2/5831008/servers/ffec9d55-2d54-4718-bc3a-0d47fb8c52c1", "rel": "self"},
        {"href": "https://dfw.servers.api.rackspacecloud.com/5831008/servers/ffec9d55-2d54-4718-bc3a-0d47fb8c52c1", "rel": "bookmark"}
     ],
     "adminPass": "q5dmoSkbYLF6"
  }
 }

  4. Get the details for the replica server and confirm that the replica server is in
    the same publicIPZoneId as the primary server.

    Request:

    curl -s https://dfw.servers.api.rackspacecloud.com/v2/5831008/servers/ffec9d55-2d54-4718-bc3a-0d47fb8c52c1
    -X GET -H "Content-Type: application/json"
    -H "X-Auth-Token: $token"

    Response:

     {"server": {
     "OS-DCF:diskConfig": "AUTO",
     "OS-EXT-STS:power_state": 1,
     "OS-EXT-STS:task_state": null,
     "OS-EXT-STS:vm_state": "active",
     "RAX-PUBLIC-IP-ZONE-ID:publicIPZoneId": "8487ac8920752e042b0c70a4f9e064157ed2e051728fe2beb6bff09f",
     "accessIPv4": "10.23.233.89",
     "accessIPv6": "2001:4801:787f:205:a8bb:ccff:fe00:e4",
     "addresses": {
        "private": [
           {"addr": "10.183.232.82","version": 4}
        ],
        "public": [
           {"addr": "2001:4801:787f:205:a8bb:ccff:fe00:e4","version": 6},
           {"addr": "10.23.233.89","version": 4}
        ]
     },
     "config_drive": "",
     "created": "2015-07-27T20:03:36Z",
     "flavor": {
        "id": "2",
        "links": [
           {"href": "https://qe-ord.servers.api.rackspacecloud.com/5831008/flavors/2","rel": "bookmark"}
        ]
     },
     "hostId": "5f4b7f1f0870880a910c4028f53c642730be6fdfa0cf5f9b7f3d126e",
     "id": "ffec9d55-2d54-4718-bc3a-0d47fb8c52c1",
     "image": {
        "id": "adb78bf4-81ae-4dce-a417-8eb2b7f7f0c3",
        "links": [
           {"href": "https://qe-ord.servers.api.rackspacecloud.com/5831008/images/adb78bf4-81ae-4dce-a417-8eb2b7f7f0c3","rel": "bookmark"}
        ]
     },
     "key_name": null,
     "links": [
        {"href": "https://qe-ord.servers.api.rackspacecloud.com/v2/5831008/servers/ffec9d55-2d54-4718-bc3a-0d47fb8c52c1","rel": "self"},
        {"href": "https://qe-ord.servers.api.rackspacecloud.com/5831008/servers/ffec9d55-2d54-4718-bc3a-0d47fb8c52c1","rel": "bookmark"}
     ],
     "metadata": {},
     "name": "isol2",
     "progress": 100,
     "status": "ACTIVE",
     "tenant_id": "5831008",
     "updated": "2015-07-27T20:04:39Z",
     "user_id": "207638"
  }
 }

Create a shared IP address and associate it with both servers

Perform the following steps from your local computer.

  1. Get port IDs for both servers. Filter the list ports operation by the
    PublicNet (network ID that is all zeroes). Find the sections of the response where the value of device_id matches the primary server, and save the corresponding ID (which is the port ID) for future reference. Do the same thing for the replica server.

    Request:

     curl -s https://dfw.networks.api.rackspacecloud.com/v2.0/ports?network_id=00000000-0000-0000-0000-000000000000
    -X GET
    -H "X-Auth-Token: $token" | python -m json.tool

    Response:

     {"ports": [
     {
        "admin_state_up": true,
        "device_id": "96bbd712-0f64-4146-bfb2-b2bd91f20319",
        "device_owner": "compute:None",
        "fixed_ips": [
           {
             "ip_address": "2001:4801:787f:205:a8bb:ccff:fe00:108",
             "subnet_id": "e170e323-b232-4bd7-9d75-14d82546c5d6"
           },
           {
              "ip_address": "10.23.233.113",
              "subnet_id": "535ca638-a358-4d02-8271-1e6f795f8a0c"
           }
        ],
        "id": "0b5a23ec-be78-4ea3-9251-b64444236c1d",
        "mac_address": "AA:BB:CC:00:01:08",
        "name": "",
        "network_id": "00000000-0000-0000-0000-000000000000",
        "security_groups": [],
        "status": "ACTIVE",
        "tenant_id": "5831008"
     },
     {
        "admin_state_up": true,
        "device_id": "ffec9d55-2d54-4718-bc3a-0d47fb8c52c1",
        "device_owner": "compute:None",
        "fixed_ips": [
           {
              "ip_address": "2001:4801:787f:205:a8bb:ccff:fe00:e4",
              "subnet_id": "e170e323-b232-4bd7-9d75-14d82546c5d6"
           },
           {
              "ip_address": "10.23.233.89",
              "subnet_id": "535ca638-a358-4d02-8271-1e6f795f8a0c"
           }
        ],
        "id": "a1bb7074-9ccc-4bc0-991e-7847de374af3",
        "mac_address": "AA:BB:CC:00:00:E4",
        "name": "",
        "network_id": "00000000-0000-0000-0000-000000000000",
        "security_groups": [],
        "status": "ACTIVE",
        "tenant_id": "5831008"
     }
  ],
  "ports_links": [
     {
        "href": "https://localhost:9696/v2.0/ports?network_id=00000000-0000-0000-0000-000000000000&marker=0b5a23ec-be78-4ea3-9251-b64444236c1d&page_reverse=True",
        "rel": "previous"
     }
  ]

    }

  2. Provision the IP address on the PublicNet ports for the primary and replica
    servers. For future reference, note the IP address and the IP address ID in the response.

    Request:

     curl -s https://dfw.networks.api.rackspacecloud.com/v2.0/ip_addresses
    -X POST -H "Content-Type: application/json"
    -H "X-Auth-Token: $token"
    -d " {"ip_address":{"network_id": "00000000-0000-0000-0000-000000000000","port_ids": ["a1bb7074-9ccc-4bc0-991e-7847de374af3", "0b5a23ec-be78-4ea3-9251-b64444236c1d"],"tenant_id": "5831008","version": 4}}"

    Response:

     {
   "ip_address":
     {
       "subnet_id": "535ca638-a358-4d02-8271-1e6f795f8a0c",
       "version": 4,
       "address": "10.23.233.31",
       "network_id": "00000000-0000-0000-0000-000000000000",
       "tenant_id": "5831008",
       "port_ids":
         [
          "a1bb7074-9ccc-4bc0-991e-7847de374af3",
          "0b5a23ec-be78-4ea3-9251-b64444236c1d"
         ],
       "type": "shared",
       "id": "e201f500-6d57-4901-b7a0-3842a3a32207"
      }
 }

  3. Confirm that both server ports share the IP address.

    Request:

     curl
 -s https://dfw.networks.api.rackspacecloud.com/v2.0/ip_addresses
 -X GET -H "Content-Type: application/json"
 -H "X-Auth-Token: $token"

    Response:

     "ip_addresses":
   {
     [
       {
         "address": "2001:4801:787f:205:a8bb:ccff:fe00:108",
         "id": "068652fe-33e2-44b6-9ad3-c0362e5d7e18",
         "network_id": "00000000-0000-0000-0000-000000000000",
         "port_ids":
           [
             "0b5a23ec-be78-4ea3-9251-b64444236c1d"
           ],
         "subnet_id": "e170e323-b232-4bd7-9d75-14d82546c5d6",
         "tenant_id": "5831008",
         "type": "fixed",
         "version": 6
       },
       {
        "address": "10.183.232.82",
        "id": "59202862-7b4c-4bad-bcef-6c33dcfc29d7",
        "network_id": "11111111-1111-1111-1111-111111111111",
        "port_ids":
          [
            "3d1269a5-090b-4fe7-b839-4dafc8b42425"
          ],
        "subnet_id": "d1c63a31-1501-46f2-aebf-992cdb5bf372",
        "tenant_id": "5831008",
        "type": "fixed",
        "version": 4
         },
       {
        "address": "10.23.233.31",
        "id": "e201f500-6d57-4901-b7a0-3842a3a32207",
        "network_id": "00000000-0000-0000-0000-000000000000",
        "port_ids":
          [
           "0b5a23ec-be78-4ea3-9251-b64444236c1d",
           "a1bb7074-9ccc-4bc0-991e-7847de374af3"
          ],
        "subnet_id": "535ca638-a358-4d02-8271-1e6f795f8a0c",
        "tenant_id": "5831008",
        "type": "shared",
        "version": 4
       },
       {
        "address": "10.23.233.89",
        "id": "f2263b79-221d-46c0-9436-2b4bf98df227",
        "network_id": "00000000-0000-0000-0000-000000000000",
        "port_ids":
          [
           "a1bb7074-9ccc-4bc0-991e-7847de374af3"
          ],
        "subnet_id": "535ca638-a358-4d02-8271-1e6f795f8a0c",
        "tenant_id": "5831008",
        "type": "fixed",
        "version": 4
       }
     ]
   }

  4. Associate the shared IP address with the primary server.

    Request:

     curl
   -vv
   -s
   -k
   https://dfw.servers.api.rackspacecloud.com/v2/5831008/servers/96bbd712-0f64-4146-bfb2-b2bd91f20319/ip_associations/e201f500-6d57-4901-b7a0-3842a3a32207
   -X PUT -H "Content-Type: application/json"
   -H "X-Auth-Token: $token"

    Response:

     {
  "ip_association":
    {
      "id": "e201f500-6d57-4901-b7a0-3842a3a32207",
      "address": "10.23.233.31"
    }
 }

  5. Associate the shared IP address with the replica server.

    Request:

     curl
   -vv
   -s
   -k
   https://dfw.servers.api.rackspacecloud.com/v2/5831008/servers/ffec9d55-2d54-4718-bc3a-0d47fb8c52c1/ip_associations/e201f500-6d57-4901-b7a0-3842a3a32207
   -X PUT
   -H "Content-Type: application/json" <br>
   -H "X-Auth-Token: $token"

    Response:

     {
   "ip_association":
     {
       "id": "e201f500-6d57-4901-b7a0-3842a3a32207",
       "address": "10.23.233.31"
     }
 }

Configure Apache2 and set up the heartbeat on the servers

Perform the following steps on the primary and replica servers. Each step
indicates where to perform the step.

  1. (Primary) Install Apache on the primary server by running the following
    commands:

     sudo apt-get update
 sudo apt-get install heartbeat
 sudo apt-get install apache2

  2. (Primary) Create the /etc/heartbeat/authkeys file on the primary server
    and enter the following text. The contents are the same for the primary server and the replica server. Substitute your own passphrase.

    File contents:

     auth 1
 1 sha1 YourSecretPassPhrase

  3. (Primary) Set the correct permissions on the /etc/heartbeat/authkeys
    file:

     chmod 600 /etc/heartbeat/authkeys

  4. (Primary) Create the /etc/heartbeat/haresources file on the primary
    server and enter the following contents (with your primary server public IP address). The contents are the same for the primary server and the replica server.

    File contents:

     primary-instance-hostname 10.23.233.113/24

  5. (Primary) Create the /etc/heartbeat/ha.cf file on primary server and
    enter the following text. The lines with comments are the ones that have to be modified.

    File contents:

     logfacility daemon
 keepalive 2
 deadtime 15
 warntime 5
 initdead 120
 udpport 694
 ucast eth0 10.23.233.89 # The IP address of the replica instance on public net
 auto_failback on
 node primary-instance-hostname # primary-instance-hostname is the name displayed by uname -n in the primary instance
 node replica-instance-hostname # replica-instance-hostname is the name displayed by uname -n in the replica instance
 respawn hacluster /usr/lib/heartbeat/ipfail
 use_logd yes

  6. (Replica) Install Apache on the replica server by running the following
    commands:

     sudo apt-get update
 sudo apt-get install heartbeat
 sudo apt-get install apache2

  7. (Replica) Create the /etc/heartbeat/authkeys file on the replica server
    and enter the following text. The contents are the same for the primary server and the replica server. Substitute your own passphrase.

    File contents:

     auth 1
 1 sha1 YourSecretPassPhrase

  8. (Replica) Set the correct permissions on the /etc/heartbeat/authkeys
    file.

     chmod 600 /etc/heartbeat/authkeys

  9. (Replica) Create the /etc/heartbeat/haresources file on the replica
    server and populate it with the shared IP address (with you primary server public IP address). The contents are the same for the primary server and the replica server.

    File contents:

     primary-instance-hostname 10.23.233.113/24

  10. (Replica) Create the /etc/heartbeat/ha.cf file on the replica server and
    enter the following text. The lines with comments are the ones that have to be modified.

    File contents:

    logfacility daemon
keepalive 2
deadtime 15
warntime 5
initdead 120
udpport 694
ucast eth0 10.23.233.89 # The ip address of the primary instance on public net
auto_failback on
node primary-instance-hostname# primary-instance-hostname is the name displayed by uname -n in the primary instance
node replica-instance-hostname # replica-instance-hostname is the name displayed by uname -n in the replica instance
respawn hacluster /usr/lib/heartbeat/ipfail use_logd yes

  11. (Replica) Restart the heartbeat on the replica server by running the following
    command:

    sudo service heartbeat restart

  12. (Primary) Set up Apache to respond with the hostname on the primary server
    by running the following command:

    echo `hostname` > /var/www/html/index.html

  13. (Replica) Set up Apache to respond with the hostname on the replica server by
    running the following command:

    echo `hostname` > /var/www/html/index.html

  14. (Primary) Restart Apache on the primary server by running the following
    command:

    sudo service apache2 restart

  15. (Replica) Restart Apache on the replica server by running the following
    command:

    sudo service apache2 restart

Test the configuration

Perform the following steps on the primary and replica servers and your
local computer. Each step indicates where to perform the step.

  1. (Primary) Validate the eth0 interface configured with the shared IP address
    on the primary server by running the following command:

     ifconfig

    Response:

     eth0 Link encap:Ethernet HWaddr aa:bb:cc:00:00:e4
 inet addr:10.23.233.89 Bcast:10.23.233.255 Mask:255.255.255.0
 inet6 addr: fe80::a8bb:ccff:fe00:e4/64 Scope:Link
 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
 RX packets:23989 errors:0 dropped:0 overruns:0 frame:0
 TX packets:6016 errors:0 dropped:0 overruns:0 carrier:0
 collisions:0 txqueuelen:1000
 RX bytes:27487494 (27.4 MB) TX bytes:805941 (805.9 KB)

 eth0:0 Link encap:Ethernet HWaddr aa:bb:cc:00:00:e4
 inet addr:10.23.233.31 Bcast:10.23.233.255 Mask:255.55.255.0
 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

 eth1 Link encap:Ethernet HWaddr aa:bb:cc:00:00:e5
 inet addr:10.183.232.82 Bcast:10.183.239.255 Mask:255.255.248.0
 inet6 addr: fe80::a8bb:ccff:fe00:e5/64 Scope:Link
 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
 RX packets:739 errors:0 dropped:0 overruns:0 frame:0
 TX packets:615 errors:0 dropped:0 overruns:0 carrier:0
 collisions:0 txqueuelen:1000
 RX bytes:52142 (52.1 KB) TX bytes:85084 (85.0 KB)

 lo Link encap:Local Loopback
 inet addr:127.0.0.1 Mask:255.0.0.0

 inet6 addr: ::1/128 Scope:Host
 UP LOOPBACK RUNNING MTU:65536 Metric:1
 RX packets:46268 errors:0 dropped:0 overruns:0 frame:0
 TX packets:46268 errors:0 dropped:0 overruns:0 carrier:0
 collisions:0 txqueuelen:0
 RX bytes:15678190 (15.6 MB) TX bytes:15678190 (15.6 MB)

  2. (Local computer) Browse to the shared IP address, which connects you to the
    primary server, by using a web browser with the shared IP address in the address bar. The browser displays
    the primary server's instance name.

  3. (Local computer) Use SSH to connect to the primary server by running the
    following command (substituting your username and your primary server IP address):

     ssh username@primary_server_ip_address

  4. (Primary) Find the gateway address by running the following command. Save
    the gateway address for future reference.

    route | grep default

  5. (Primary) Turn off the eth0 interface by running the following command:

    sudo ifconfig eth0 down

  6. (Local computer) Use SSH to connect to the replica server by running the
    following command (substituting your username and your replica server IP address):

    ssh username@replica_server_ip_address

  7. (Local computer) After a few moments, browse to the shared IP address,
    which connects you to the replica server, by using a web browser with the shared IP address in the address bar. The browser displays the replica server's instance name.

  8. (Replica) Validate the eth0 interface configured with shared IP address on
    the replica server by running the following command:

     sudo ifconfig

    Response:

     eth0 Link encap:Ethernet HWaddr aa:bb:cc:00:01:08
 inet addr:10.23.233.113 Bcast:10.23.233.255 Mask:255.255.255.0
 inet6 addr: fe80::a8bb:ccff:fe00:108/64 Scope:Link
 inet6 addr: 2001:4801:787f:205:a8bb:ccff:fe00:108/64 Scope:Global
 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
 RX packets:24551 errors:0 dropped:0 overruns:0 frame:0
 TX packets:6662 errors:0 dropped:0 overruns:0 carrier:0
 collisions:0 txqueuelen:1000
 RX bytes:27526381 (27.5 MB) TX bytes:848469 (848.4 KB)

 eth0:0 Link encap:Ethernet HWaddr aa:bb:cc:00:01:08
 inet addr:10.23.233.31 Bcast:10.23.233.255 Mask:255.255.255.0
 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

 eth1 Link encap:Ethernet HWaddr aa:bb:cc:00:01:09
 inet addr:10.183.232.104 Bcast:10.183.239.255 Mask:255.255.248.0
 inet6 addr: fe80::a8bb:ccff:fe00:109/64 Scope:Link
 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
 RX packets:0 errors:0 dropped:0 overruns:0 frame:0
 TX packets:16 errors:0 dropped:0 overruns:0 carrier:0
 collisions:0 txqueuelen:1000
 RX bytes:0 (0.0 B) TX bytes:1296 (1.2 KB)

 lo Link encap:Local Loopback
 inet addr:127.0.0.1 Mask:255.0.0.0
 inet6 addr: ::1/128 Scope:Host
 UP LOOPBACK RUNNING MTU:65536 Metric:1
 RX packets:778 errors:0 dropped:0 overruns:0 frame:0
 TX packets:778 errors:0 dropped:0 overruns:0 carrier:0
 collisions:0 txqueuelen:0
 RX bytes:256853 (256.8 KB) TX bytes:256853 (256.8 KB)

  9. (Primary) Turn on the eth0 interface by running the following command:

    sudo ifconfig eth0 up

  10. (Primary) Restore the shared IP address to the primary instance by running
    the following command (using the gateway address from step 4):

     route add default gw <gateway-address>

Updated about 1 year ago