DevStack Version: stein OS Version: Ubuntu 16.04 xenial The floating ip is not reachable from my local network

Private network : 192.168.1.0/24 with GW 192.168.1.1
Public network (External network) :10.162.3.240/28  with GW 10.162.3.241

Even though I've specified  the gateway of the external network as 10.162.3.241, this ip is no where assigned 

Below are the router interface details.

root@packstack1:/opt/stack/logs# ip netns exec qrouter-4cef2a19-3cf0-4b28-b791-ebcc3ba98dce ifconfig
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:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

qg-71af9eeb-83 Link encap:Ethernet  HWaddr fa:16:3e:8b:4f:45
          inet addr:10.162.3.245  Bcast:10.162.3.255  Mask:255.255.255.240
          inet6 addr: fe80::f816:3eff:fe8b:4f45/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:24 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1
          RX bytes:0 (0.0 B)  TX bytes:1712 (1.7 KB)

qr-c8482326-e2 Link encap:Ethernet  HWaddr fa:16:3e:00:df:5c
          inet addr:192.168.1.1  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::f816:3eff:fe00:df5c/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1450  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:13 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1
          RX bytes:0 (0.0 B)  TX bytes:990 (990.0 B)

External Network DHCP Namespace
=============================
root@packstack1:/opt/stack/logs# ip netns exec qdhcp-5fc0fe3f-18b0-46a1-8245-325291718e25 ifconfig
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:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

tap9e857f1c-a3 Link encap:Ethernet  HWaddr fa:16:3e:42:32:d2
          inet addr:10.162.3.242  Bcast:10.162.3.255  Mask:255.255.255.240
          inet6 addr: fe80::f816:3eff:fe42:32d2/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:5 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1
          RX bytes:0 (0.0 B)  TX bytes:438 (438.0 B)

 - Private network namespace
===========================
root@packstack1:/opt/stack/logs# ip netns exec qdhcp-7d016c87-b2cb-4bdd-87fc-be79c5ca2a6a ifconfig
lo        Link encap:Local Loopback ...