I can ping all IPs in my DHCP pool!

asked 2017-01-01 23:29:05 -0500

AmirV gravatar image

updated 2017-01-02 00:17:42 -0500

I have three launched VMs:

root@controller:/home/controller_admin/Desktop# openstack server list
+------------------------+------+--------+-----------------------+------------+
| ID                     | Name | Status | Networks              | Image Name |
+------------------------+------+--------+-----------------------+------------+
| c85ca518-b05f-         | vm1  | ACTIVE | provider=172.16.0.105 | cirros     |
| 46f9-9053-0e897da50d1e |      |        |                       |            |
| b5294b65-5a6e-4b1c-    | vm2  | ACTIVE | provider=172.16.0.103 | cirros     |
| ab8e-46fc39ad1e0b      |      |        |                       |            |
| 3a4342e5-8209-49ae-    | vm0  | ACTIVE | provider=172.16.0.107 | cirros     |
| 8c22-317133cc67ba      |      |        |                       |            |
+------------------------+------+--------+-----------------------+------------+

Also, I have 4 ports: 1 for DHCP and 3 for VMs:

root@controller:/home/controller_admin/Desktop# neutron port-list
+-------------------------------------+------+-------------------+--------------------------------------+
| id                                  | name | mac_address       | fixed_ips                            |
+-------------------------------------+------+-------------------+--------------------------------------+
| 53a71d07-4d31-41c7-bd2a-            |      | fa:16:3e:79:53:d2 | {"subnet_id": "98c191e0-23ea-4778-8c |
| fa1026286611                        |      |                   | d8-2e1b98d38559", "ip_address":      |
|                                     |      |                   | "172.16.0.100"}                      |
| 5b53851c-                           |      | fa:16:3e:99:4a:47 | {"subnet_id": "98c191e0-23ea-4778-8c |
| cc37-4477-9474-9470fe034b03         |      |                   | d8-2e1b98d38559", "ip_address":      |
|                                     |      |                   | "172.16.0.105"}                      |
| 660b7074-9ced-4264-9244-4dc60ec6e58 |      | fa:16:3e:ee:46:b8 | {"subnet_id": "98c191e0-23ea-4778-8c |
| 1                                   |      |                   | d8-2e1b98d38559", "ip_address":      |
|                                     |      |                   | "172.16.0.103"}                      |
| 8b6bfc26-eb41-4372-92df-            |      | fa:16:3e:96:9c:04 | {"subnet_id": "98c191e0-23ea-4778-8c |
| 6a74ec169a4b                        |      |                   | d8-2e1b98d38559", "ip_address":      |
|                                     |      |                   | "172.16.0.107"}                      |
+-------------------------------------+------+-------------------+--------------------------------------+

The problem is I can ping ALL the unassigned IP addresses (e.g. 172.16.0.200 or 172.16.0.250):

root@controller:/home/controller_admin/Desktop# ping 172.16.0.200
PING 172.16.0.200 (172.16.0.200) 56(84) bytes of data.
64 bytes from 172.16.0.200: icmp_seq=1 ttl=248 time=26.6 ms
64 bytes from 172.16.0.200: icmp_seq=2 ttl=248 time=28.2 ms
64 bytes from 172.16.0.200: icmp_seq=3 ttl=248 time=294 ms
64 bytes from 172.16.0.200: icmp_seq=4 ttl=248 time=25.6 ms

Why is it happening? What is going on??

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Comments

I would start by checking the MAC addresses associated to those IP addresses.

Bernd Bausch gravatar imageBernd Bausch ( 2017-01-02 04:20:32 -0500 )edit

Elaborate please. I can't see the issue with the Mac Addresses.

AmirV gravatar imageAmirV ( 2017-01-02 05:25:46 -0500 )edit

I cannot understand the network topology. You use flat provider networking? Normally, from controller you need router to connect on vms. Have a layer 3 router configure? About @Bernd suggestion is to check if the reply of ping comes from corrct mac address, you can check with tcpdump or with arp.

tze gravatar imagetze ( 2017-01-02 11:23:32 -0500 )edit

Yes my provider is flat. I simply use a physical switch to form the provider network. I dont have any vrouters. I have configured a provider network and one subnet.

AmirV gravatar imageAmirV ( 2017-01-02 12:01:27 -0500 )edit

Your private subnet (on controller) is 172.16.0.0/24 or something else? Routing table (on controller)?

tze gravatar imagetze ( 2017-01-02 15:45:21 -0500 )edit