I'm trying to get this to work with fedora16 right now and it seems that the kernel .config it has: CONFIG_NET_NS=y  so it should have netns support. 

I believe the issue might be an outdated route2 package (iproute-2.6.39-6.fc16.x86_64) . I installed the latest iproute2 package and this is what I'm getting now. 


2012-08-11 15:39:14    DEBUG [quantum.agent.linux.utils] Running command: sudo ip link set tap09158e3a-1c address fa:16:3e:b9:5b:c2
2012-08-11 15:39:14    DEBUG [quantum.agent.linux.utils]
Command: ['sudo', 'ip', 'link', 'set', 'tap09158e3a-1c', 'address', 'fa:16:3e:b9:5b:c2']
Exit code: 0
Stdout: ''
Stderr: ''
2012-08-11 15:39:14    DEBUG [quantum.agent.linux.utils] Running command: sudo ip -o netns list
2012-08-11 15:39:14    DEBUG [quantum.agent.linux.utils]
Command: ['sudo', 'ip', '-o', 'netns', 'list']
Exit code: 0
Stdout: ''
Stderr: ''
2012-08-11 15:39:14    DEBUG [quantum.agent.linux.utils] Running command: sudo ip netns add 6e57a8cd-103c-42a3-be52-6a152d504994
2012-08-11 15:39:14    DEBUG [quantum.agent.linux.utils]
Command: ['sudo', 'ip', 'netns', 'add', '6e57a8cd-103c-42a3-be52-6a152d504994']
Exit code: 0
Stdout: ''
Stderr: ''
2012-08-11 15:39:14    DEBUG [quantum.agent.linux.utils] Running command: sudo ip netns exec 6e57a8cd-103c-42a3-be52-6a152d504994 ip link set lo up
2012-08-11 15:39:15    DEBUG [quantum.agent.linux.utils]
Command: ['sudo', 'ip', 'netns', 'exec', '6e57a8cd-103c-42a3-be52-6a152d504994', 'ip', 'link', 'set', 'lo', 'up']
Exit code: 0
Stdout: ''
Stderr: ''
2012-08-11 15:39:15    DEBUG [quantum.agent.linux.utils] Running command: sudo ip link set tap09158e3a-1c netns 6e57a8cd-103c-42a3-be52-6a152d504994
2012-08-11 15:39:15    DEBUG [quantum.agent.linux.utils]
Command: ['sudo', 'ip', 'link', 'set', 'tap09158e3a-1c', 'netns', '6e57a8cd-103c-42a3-be52-6a152d504994']
Exit code: 0
Stdout: ''
Stderr: ''
2012-08-11 15:39:15    DEBUG [quantum.agent.linux.utils] Running command: sudo ip netns exec 6e57a8cd-103c-42a3-be52-6a152d504994 ip link set tap09158e3a-1c up
2012-08-11 15:39:15    DEBUG [quantum.agent.linux.utils]
Command: ['sudo', 'ip', 'netns', 'exec', '6e57a8cd-103c-42a3-be52-6a152d504994', 'ip', 'link', 'set', 'tap09158e3a-1c', 'up']
Exit code: 1
Stdout: ''
Stderr: 'mount of /sys failed: Device or resource busy\n'
2012-08-11 15:39:15  WARNING [quantum.agent.dhcp_agent] Unable to enable dhcp. Exception:
Command: ['sudo', 'ip', 'netns', 'exec', '6e57a8cd-103c-42a3-be52-6a152d504994', 'ip', 'link', 'set', 'tap09158e3a-1c', 'up']
Exit code: 1
Stdout: ''
Stderr: 'mount of /sys failed: Device or resource busy\n'
2012-08-11 15:39:18    DEBUG [quantum.agent.linux.dhcp] Unable to access /opt/stack/data/dhcp/6e57a8cd-103c-42a3-be52-6a152d504994/pid
2012-08-11 15:39:18    DEBUG [quantum.agent.linux.utils] Running command: sudo cat /proc/None/cmdline
2012-08-11 15:39:18    DEBUG [quantum.agent.linux.utils]
Command: ['sudo', 'cat', '/proc/None/cmdline']
Exit code: 1
Stdout: ''
Stderr: 'cat: /proc/None/cmdline: No such file or directory\n'
2012-08-11 15:39:18    DEBUG [quantum.agent.linux.utils] Running command: sudo ip netns exec 6e57a8cd-103c-42a3-be52-6a152d504994 ip -o link show tap09158e3a-1c
2012-08-11 15:39:18    DEBUG [quantum.agent.linux.utils]
Command: ['sudo', 'ip', 'netns', 'exec', '6e57a8cd-103c-42a3-be52-6a152d504994', 'ip', '-o', 'link', 'show', 'tap09158e3a-1c']
Exit code: 0