Gateway only desn't work in dual nic environment

[sirio81]

dog node list
  Id Host:Port V-Nodes Zone
   0 192.168.2.59:7000 0 990030016
   1 192.168.10.4:7000 127 67807424
   2 192.168.10.5:7000 128 84584640
   3 192.168.10.6:7000 128 101361856
   4 192.168.10.7:7000 128 118139072

Node id 0 is a gateway only with a single nic
sheep -g /var/lib/sheepdog -c zookeeper:192.168.2.44:2181,192.168.2.45:2181,192.168.2.46:2181

The other nodes have 2 nics
sheep -n /var/lib/sheepdog /mnt/sheep/0 -c zookeeper:192.168.2.44:2181,192.168.2.45:2181,192.168.2.46:2181 -i host=192.168.10.6 port=3333

THE PROBLEM: Dog node list from the gateway only doesn't show any vdi.

In sheep.log I find these alert messages
Jul 04 15:14:13 ALERT [block] do_get_vdis(528) failed to get vdi bitmap from IPv4 ip:192.168.10.4 port:7000
Jul 04 15:14:16 ALERT [block] do_get_vdis(528) failed to get vdi bitmap from IPv4 ip:192.168.10.5 port:7000
Jul 04 15:14:19 ALERT [block] do_get_vdis(528) failed to get vdi bitmap from IPv4 ip:192.168.10.6 port:7000
Jul 04 15:14:22 ALERT [block] do_get_vdis(528) failed to get vdi bitmap from IPv4 ip:192.168.10.7 port:7000

In such scenario, the gateway only should use its nic as a fall back nic.