I have same issue in a test deployment with only one node.

root@ubuntu01:~# nova-manage service list
Binary           Host                                 Zone             Status     State Updated_At
nova-scheduler   ubuntu01                             internal         enabled    :-)   2013-10-06 16:43:28
nova-conductor   ubuntu01                             internal         enabled    :-)   2013-10-06 16:43:28
nova-network     ubuntu01                             internal         enabled    :-)   2013-10-06 16:43:24
nova-cert        ubuntu01                             internal         enabled    :-)   2013-10-06 16:43:22
nova-consoleauth ubuntu01                             internal         enabled    :-)   2013-10-06 16:43:28
nova-compute     ubuntu01                             nova             enabled    :-)   2013-10-06 16:43:29

root@ubuntu01:~# nova network-show dc6cc0b2-bed5-45af-9dbe-6db52dd9579e
+---------------------+--------------------------------------+
| Property            | Value                                |
+---------------------+--------------------------------------+
| bridge              | br100                                |
| vpn_public_port     | None                                 |
| dhcp_start          | 192.168.210.2                        |
| bridge_interface    | eth0                                 |
| updated_at          | 2013-10-06T15:42:47.000000           |
| id                  | dc6cc0b2-bed5-45af-9dbe-6db52dd9579e |
| cidr_v6             | None                                 |
| deleted_at          | None                                 |
| gateway             | 192.168.210.1                        |
| rxtx_base           | None                                 |
| label               | private                              |
| priority            | None                                 |
| project_id          | None                                 |
| vpn_private_address | None                                 |
| deleted             | 0                                    |
| vlan                | None                                 |
| broadcast           | 192.168.210.255                      |
| netmask             | 255.255.255.0                        |
| injected            | False                                |
| cidr                | 192.168.210.0/24                     |
| vpn_public_address  | None                                 |
| multi_host          | False                                |
| dns2                | None                                 |
| created_at          | 2013-10-06T15:41:01.000000           |
| host                | ubuntu01                             |
| gateway_v6          | None                                 |
| netmask_v6          | None                                 |
| dns1                | 8.8.4.4                              |
+---------------------+--------------------------------------+

root@ubuntu01:~# ifconfig br100
br100     Link encap:Ethernet  direcciónHW 00:0c:29:85:46:af
          Direc. inet:192.168.210.1  Difus.:192.168.210.255  Másc:255.255.255.0
          Dirección inet6: fe80::a007:67ff:fe5e:90e3/64 Alcance:Enlace
          ACTIVO DIFUSIÓN FUNCIONANDO MULTICAST  MTU:1500  Métrica:1
          Paquetes RX:12252 errores:0 perdidos:10 overruns:0 frame:0
          Paquetes TX:12463 errores:0 perdidos:0 overruns:0 carrier:0
          colisiones:0 long.colaTX:0
          Bytes RX:1156170 (1.1 MB)  TX bytes:6932529 (6.9 MB)

My rabbitmq isn't overloaded.