I have an open stack VM instance having two NICs added from same Sub-Net. Both nics are configured for DHCP. When i start VM instance it gets one DHCP ip on each interface. I am able to ping this VM instance from other VM intance on same network and other VM from inside this VM instance. Problem comes when i assign floating IP to one of the interface. I am able to access VM from floating IP if Floating IP is assigned to the interface which has the default gateway.
i have two interface eth0 ad eth1 and having private DHCP ip assigned
[#] ifconfig|egrep "Link encap|inet addr"
eth0 Link encap:Ethernet HWaddr FA:16:3E:44:CA:E5
inet addr:10.0.0.13 Bcast:10.0.0.255 Mask:255.255.255.0
eth1 Link encap:Ethernet HWaddr FA:16:3E:DA:95:C5
inet addr:10.0.0.155 Bcast:10.0.0.255 Mask:255.255.255.0
Following is routing table:
[#] netstat -ar
Destination Gateway Genmask Flags MSS Window irtt Iface
10.0.0.0 * 255.255.255.0 U 0 0 0 eth0
10.0.0.0 * 255.255.255.0 U 0 0 0 eth1
link-local * 255.255.0.0 U 0 0 0 eth0
link-local * 255.255.0.0 U 0 0 0 eth1
default host-10-0-0-1.s 0.0.0.0 UG 0 0 0 eth1
If I associate some floating IP with private IP '10.0.0.155' (assigned to eth1) and default gateway is also configured out of eth1 as shown in routing table above then I am able to access VM by floating IP. But if I associate floating IP with private IP '10.0.0.13' (assigned to eth0) then I am not able to access VM by floating IP. Now if I delete this default route and add new route with same gateway but this time use interface eth0. Then on attaching floating IP with IP '10.0.0.13' (assigned to eth0) I can access VM but now not able to access VM if I assign floating IP to private IP '10.0.0.1155' (assigned to eth1).
