I've installed Juno on Ubuntu 14.04.2 LTS and instances can't get IP from DHCP. No errors in logs.

Network Node

root@network:~# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
    valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 00:50:56:b1:79:07 brd ff:ff:ff:ff:ff:ff
    inet 10.8.1.131/24 brd 10.8.1.255 scope global eth0
    valid_lft forever preferred_lft forever
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 00:50:56:b1:2e:45 brd ff:ff:ff:ff:ff:ff
    inet 10.0.1.21/24 brd 10.0.1.255 scope global eth1
    valid_lft forever preferred_lft forever
4: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq master ovs-system state UP group default qlen 1000
    link/ether 00:50:56:b1:12:ba brd ff:ff:ff:ff:ff:ff
5: ovs-system: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default
    link/ether be:0e:db:dc:3d:56 brd ff:ff:ff:ff:ff:ff
6: br-ex: <BROADCAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default
    link/ether 00:50:56:b1:12:ba brd ff:ff:ff:ff:ff:ff
9: br-int: <BROADCAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default
    link/ether d6:bf:05:38:7d:43 brd ff:ff:ff:ff:ff:ff
13: phy-br-ex: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master ovs-system state UP group default qlen 1000
    link/ether 1a:74:47:c1:1b:1b brd ff:ff:ff:ff:ff:ff
14: int-br-ex: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master ovs-system state UP group default qlen 1000
    link/ether 9e:ae:d6:8e:e3:b0 brd ff:ff:ff:ff:ff:ff
15: br-tun: <BROADCAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default
    link/ether c6:7b:a3:9b:ea:4e brd ff:ff:ff:ff:ff:ff

root@network:~# ip netns
qrouter-eb218066-143d-42b4-ba90-0f719defde66
qdhcp-38639607-391a-4622-ac0e-37d5a32ced1b

root@network:~# ip netns exec qrouter-eb218066-143d-42b4-ba90-0f719defde66 ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
    valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
    valid_lft forever preferred_lft forever
16: qr-3a45f5b8-01: <BROADCAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default
    link/ether fa:16:3e:a8:55:0b brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.1/24 brd 192.168.1.255 scope global qr-3a45f5b8-01
    valid_lft forever preferred_lft forever
    inet6 fe80::f816:3eff:fea8:550b/64 scope link
    valid_lft forever preferred_lft forever ...