Move network device between Linux network namespaces
In Linux, set up 2 network namespaces, ns1 and ns2. ip netns list can view the 2 network namespaces.
If I move one network device from Linux root namespace to ns1 then from ns1 to ns2, then delete ns2, I expect that the network device can move back to ns1.
The actual result is that eth1 is back to Linux root network namespace. I'm not sure whether it's as expected.
Here is the detail test scenario:
ip netns add ns1ip netns add ns2ip link set eth1 netns ns1ip netns exec ns1 ip link set eth1 netns ns2ip netns del ns2
Expected result: eth1 will be in ns1
Actual result: eth1 is back in Linux root namespace 1
Question: is there any method to realize such scenario to make sure device can be back to ns1 not Linux root network namespace 1?
linux network-namespaces
edited Feb 1 at 23:54
guntbert
1,06111017
asked Jun 15 '18 at 7:52
Pamela MeiPamela Mei
61
add a comment |
In Linux, set up 2 network namespaces, ns1 and ns2. ip netns list can view the 2 network namespaces.
If I move one network device from Linux root namespace to ns1 then from ns1 to ns2, then delete ns2, I expect that the network device can move back to ns1.
The actual result is that eth1 is back to Linux root network namespace. I'm not sure whether it's as expected.
Here is the detail test scenario:
ip netns add ns1ip netns add ns2ip link set eth1 netns ns1ip netns exec ns1 ip link set eth1 netns ns2ip netns del ns2
Expected result: eth1 will be in ns1
Actual result: eth1 is back in Linux root namespace 1
Question: is there any method to realize such scenario to make sure device can be back to ns1 not Linux root network namespace 1?
linux network-namespaces
edited Feb 1 at 23:54
guntbert
1,06111017
asked Jun 15 '18 at 7:52
Pamela MeiPamela Mei
61
Make ns2 a child of ns1.
– Patrick
Jun 15 '18 at 12:28
To overcome this limitation, you could have an event loop running (on the output of)ip monitor linkto detect the reapparition of the device on the initial net namespace, and immediately cast it to ns1. Interface's name could be different from the former in some cases of renaming or naming conflict.
– A.B
Jan 7 at 18:45
add a comment |
In Linux, set up 2 network namespaces, ns1 and ns2. ip netns list can view the 2 network namespaces.
If I move one network device from Linux root namespace to ns1 then from ns1 to ns2, then delete ns2, I expect that the network device can move back to ns1.
The actual result is that eth1 is back to Linux root network namespace. I'm not sure whether it's as expected.
Here is the detail test scenario:
ip netns add ns1ip netns add ns2ip link set eth1 netns ns1ip netns exec ns1 ip link set eth1 netns ns2ip netns del ns2
Expected result: eth1 will be in ns1
Actual result: eth1 is back in Linux root namespace 1
Question: is there any method to realize such scenario to make sure device can be back to ns1 not Linux root network namespace 1?
linux network-namespaces
edited Feb 1 at 23:54
guntbert
1,06111017
asked Jun 15 '18 at 7:52
Pamela MeiPamela Mei
61
In Linux, set up 2 network namespaces, ns1 and ns2. ip netns list can view the 2 network namespaces.
If I move one network device from Linux root namespace to ns1 then from ns1 to ns2, then delete ns2, I expect that the network device can move back to ns1.
The actual result is that eth1 is back to Linux root network namespace. I'm not sure whether it's as expected.
Here is the detail test scenario:
ip netns add ns1ip netns add ns2ip link set eth1 netns ns1ip netns exec ns1 ip link set eth1 netns ns2ip netns del ns2
Expected result: eth1 will be in ns1
Actual result: eth1 is back in Linux root namespace 1
Question: is there any method to realize such scenario to make sure device can be back to ns1 not Linux root network namespace 1?
linux network-namespaces
linux network-namespaces
edited Feb 1 at 23:54
guntbert
1,06111017
asked Jun 15 '18 at 7:52
Pamela MeiPamela Mei
61
edited Feb 1 at 23:54
guntbert
1,06111017
asked Jun 15 '18 at 7:52
Pamela MeiPamela Mei
61
edited Feb 1 at 23:54
guntbert
1,06111017
edited Feb 1 at 23:54
guntbert
1,06111017
edited Feb 1 at 23:54
guntbert
1,06111017
1,06111017
asked Jun 15 '18 at 7:52
Pamela MeiPamela Mei
61
asked Jun 15 '18 at 7:52
Pamela MeiPamela Mei
61
asked Jun 15 '18 at 7:52
Pamela MeiPamela Mei
61
61
Make ns2 a child of ns1.
– Patrick
Jun 15 '18 at 12:28
To overcome this limitation, you could have an event loop running (on the output of)ip monitor linkto detect the reapparition of the device on the initial net namespace, and immediately cast it to ns1. Interface's name could be different from the former in some cases of renaming or naming conflict.
– A.B
Jan 7 at 18:45
add a comment |
Make ns2 a child of ns1.
– Patrick
Jun 15 '18 at 12:28
To overcome this limitation, you could have an event loop running (on the output of)ip monitor linkto detect the reapparition of the device on the initial net namespace, and immediately cast it to ns1. Interface's name could be different from the former in some cases of renaming or naming conflict.
– A.B
Jan 7 at 18:45
Make ns2 a child of ns1.
– Patrick
Jun 15 '18 at 12:28
Make ns2 a child of ns1.
– Patrick
Jun 15 '18 at 12:28
To overcome this limitation, you could have an event loop running (on the output of)
ip monitor link to detect the reapparition of the device on the initial net namespace, and immediately cast it to ns1. Interface's name could be different from the former in some cases of renaming or naming conflict.– A.B
Jan 7 at 18:45
To overcome this limitation, you could have an event loop running (on the output of)
ip monitor link to detect the reapparition of the device on the initial net namespace, and immediately cast it to ns1. Interface's name could be different from the former in some cases of renaming or naming conflict.– A.B
Jan 7 at 18:45
add a comment |
1 Answer
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As far as I know, there is no way to enforce "physical" network interfaces return to a different network namespace than the root network namespace. Contrary to Patrick's comment, the Linux kernel considers network namespace to be flat (see ioctl_ns - ioctl() operations for Linux namespaces, which explicitly mentions only PID and user namespaces to be hierarchical).
Because there is no hierarchy for network namespaces defined (which would be difficult to apply to IP stacks, addresses, and route tables), Linux has the return-to-home rule which moves network interfaces back into the network namespace joined/created by init(1).
All ip netns add ... does is create a new network namespace by calling unshare() and then bind-mounts it into /run/netns/ns1 to keep it floating alive. The next ip nets add ... starts anew, mount-binding another network namespace into /run/netns/ns2. Two completely unrelated network namespaces.
answered Jun 25 '18 at 21:08
TheDiveOTheDiveO
25811
add a comment |
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As far as I know, there is no way to enforce "physical" network interfaces return to a different network namespace than the root network namespace. Contrary to Patrick's comment, the Linux kernel considers network namespace to be flat (see ioctl_ns - ioctl() operations for Linux namespaces, which explicitly mentions only PID and user namespaces to be hierarchical).
Because there is no hierarchy for network namespaces defined (which would be difficult to apply to IP stacks, addresses, and route tables), Linux has the return-to-home rule which moves network interfaces back into the network namespace joined/created by init(1).
All ip netns add ... does is create a new network namespace by calling unshare() and then bind-mounts it into /run/netns/ns1 to keep it floating alive. The next ip nets add ... starts anew, mount-binding another network namespace into /run/netns/ns2. Two completely unrelated network namespaces.
answered Jun 25 '18 at 21:08
TheDiveOTheDiveO
25811
add a comment |
As far as I know, there is no way to enforce "physical" network interfaces return to a different network namespace than the root network namespace. Contrary to Patrick's comment, the Linux kernel considers network namespace to be flat (see ioctl_ns - ioctl() operations for Linux namespaces, which explicitly mentions only PID and user namespaces to be hierarchical).
Because there is no hierarchy for network namespaces defined (which would be difficult to apply to IP stacks, addresses, and route tables), Linux has the return-to-home rule which moves network interfaces back into the network namespace joined/created by init(1).
All ip netns add ... does is create a new network namespace by calling unshare() and then bind-mounts it into /run/netns/ns1 to keep it floating alive. The next ip nets add ... starts anew, mount-binding another network namespace into /run/netns/ns2. Two completely unrelated network namespaces.
answered Jun 25 '18 at 21:08
TheDiveOTheDiveO
25811
add a comment |
As far as I know, there is no way to enforce "physical" network interfaces return to a different network namespace than the root network namespace. Contrary to Patrick's comment, the Linux kernel considers network namespace to be flat (see ioctl_ns - ioctl() operations for Linux namespaces, which explicitly mentions only PID and user namespaces to be hierarchical).
Because there is no hierarchy for network namespaces defined (which would be difficult to apply to IP stacks, addresses, and route tables), Linux has the return-to-home rule which moves network interfaces back into the network namespace joined/created by init(1).
All ip netns add ... does is create a new network namespace by calling unshare() and then bind-mounts it into /run/netns/ns1 to keep it floating alive. The next ip nets add ... starts anew, mount-binding another network namespace into /run/netns/ns2. Two completely unrelated network namespaces.
answered Jun 25 '18 at 21:08
TheDiveOTheDiveO
25811
As far as I know, there is no way to enforce "physical" network interfaces return to a different network namespace than the root network namespace. Contrary to Patrick's comment, the Linux kernel considers network namespace to be flat (see ioctl_ns - ioctl() operations for Linux namespaces, which explicitly mentions only PID and user namespaces to be hierarchical).
Because there is no hierarchy for network namespaces defined (which would be difficult to apply to IP stacks, addresses, and route tables), Linux has the return-to-home rule which moves network interfaces back into the network namespace joined/created by init(1).
All ip netns add ... does is create a new network namespace by calling unshare() and then bind-mounts it into /run/netns/ns1 to keep it floating alive. The next ip nets add ... starts anew, mount-binding another network namespace into /run/netns/ns2. Two completely unrelated network namespaces.
answered Jun 25 '18 at 21:08
TheDiveOTheDiveO
25811
edited Jun 26 '18 at 17:38
answered Jun 25 '18 at 21:08
TheDiveOTheDiveO
25811
answered Jun 25 '18 at 21:08
TheDiveOTheDiveO
25811
answered Jun 25 '18 at 21:08
TheDiveOTheDiveO
25811
25811
add a comment |
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Make ns2 a child of ns1.
– Patrick
Jun 15 '18 at 12:28
To overcome this limitation, you could have an event loop running (on the output of)
ip monitor linkto detect the reapparition of the device on the initial net namespace, and immediately cast it to ns1. Interface's name could be different from the former in some cases of renaming or naming conflict.– A.B
Jan 7 at 18:45