Questions tagged [network-namespaces]

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1answer
775 views

How to get the Linux network namespace for a tap/tun device referenced in /proc/[PID]/fdinfo/[FD]?

I want to correctly match TAP/TUN devices with the processes they are using, and I want to do this from outside of these processes using TAP/TUN devices (that is, I cannot issue any ioctl()s because I ...
1
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0answers
357 views

NAT box with two external interfaces and two network namespaces

I have an ARM embedded system with kernel 4.9.62 that has two physical interfaces as shown below: ________ +-------...
3
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1answer
787 views

Ping not working in a new C container

I've been working on writing my own Linux container from scratch in C. I've borrowed code from several places and put up a basic version with namespaces & cgroups. Basically, I clone a new ...
4
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1answer
263 views

Is there a file that associates a thread to its network namespace?

/proc/[pid]/ns/net contains a link to the inode representing the network namespace of the process with PID [pid]. Is there something similar for threads? My use case is a multi-threaded application, ...
1
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0answers
267 views

How do you use cgroups from within a network namespace

I just discovered that mount | grep cgroup returns nothing when you are not in the default network namespace. I can't really find any documentation on this except for that "network namespaces isolate ...
0
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1answer
972 views

Route from netns through a veth link

I have created a network namespace (with ip netns add) and a pair of veth links, virt-a and virt-b. The physical link in the root namespace is named eth0. virt-a is in the root namespace and virt-b is ...
1
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0answers
2k views

How to delete network namespace, no pids option available for ip netns [duplicate]

How to clean up network namespace, CentOS 6.5 does not have ip netns pids option, so can't use ip netns pids ns-2001 | xargs kill ip netns list | grep ns-2001 ns-2001 ip netns pids ns-2001 | xargs ...
1
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1answer
263 views

dnsmasq running in namespace can't take queries from within namespace

I've set up a default dnsmasq.conf with essentially no modifications except: listen-address=192.168.42.2 interface=veth1 # Also tried without server=8.8.8.8 And my /etc/hosts looks like this: 127.0....
2
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1answer
1k views

Is it possible to send packets between network namespaces using only TUN/TAP interfaces?

I am trying to understand the difference between different types of (virtual) interfaces (e.g. TUN/TAP, veth etc.) and was studying some of these types within the context of containers. Is it ...
0
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1answer
661 views

Can I lock down access to a TCP port in Linux

I'm trying to secure a single-node Elasticsearch machine. Basically, I want to put Elasticsearch behind a reverse proxy (nginx) and make sure that the only way any user or process can communicate with ...
3
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1answer
906 views

firejail : only let a program access localhost

I have this local network service and this client program needing to access it. I am running them both as an unprivileged user. I am looking for a way to sandbox the client using firejail, in a way ...
0
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1answer
381 views

Can I assign a virtual interface of wireless to a network namespace?

I am trying to make a VPN router while keeping the host itself accessing Internet without VPN. The host has only one NIC which is wireless. So I have added two virtual interfaces via iw phy phy0 ...
0
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1answer
964 views

How to Keep Network Namespace after reboot

I have created a network namespace, but after I have reboot, it've been removed. I don't found an answer at this problem on the internet, so this is why I'm asking you : Is there a way to keep a ...
1
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0answers
586 views

How to run ip netns exec without password?

I'm on arch and am using a network namespace wiredlan for ethernet, using it for LAN based applications and big downloads. I run commands/apps on the netns as: alias runonlan='sudo ip netns exec ...
7
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1answer
2k views

Switching into a network namespace does not change /sys/class/net?

The Linux man page for network namespaces(7) says: Network namespaces provide isolation of the system resources associated with networking: [...], the /sys/class/net directory, [...]. However, ...
0
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0answers
36 views

Linux processes without certain namespaces?

When chromium is running I see processes in /proc/[PID]/ where some of the namespace links inside /proc/[PID]/ns/do link to nothing, that is, they cannot be readlinked and return errors instead. Also ...
2
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1answer
3k views

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 ...
1
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0answers
452 views

iptables-save behaviour in network namespace in linux

My setup: Linux 4.16.13-2-ARCH iproute2 4.16.0-1 iptables 1.6.2-2 Issue: Output of iptables-save is empty inside network namespace. If iptables -L called before, iptables-save provides correct ...
7
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2answers
4k views

Separate DNS configuration in each network namespace

I've set up several network namespaces on my Linux system (kernel version 3.10), and now I want to configure each network namespace to have its own DNS settings. I created resolv.conf files in each /...
2
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1answer
510 views

Access /proc/pid/ns/net without running query process as root?

In a program I'm enumerating network namespaces by scanning /proc/pid/ for ns/net (sym) links. This program runs inside the "root" namespaces (original init) of the host itself. Normally, I need to ...
11
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3answers
10k views

How to find the network namespace of a veth peer ifindex?

Task I need to unambiguously and without "holistic" guessing find the peer network interface of a veth end in another network namespace. Theory ./. Reality Albeit a lot of documentation and also ...
0
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0answers
395 views

Creating an exact copy of a whole process?

fork() forks a process, but it will not copy all of its threads; nor will it create a clone of all its fds: the fds are shared between parent and child. I want a way of do a complete fork. So after I ...
1
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1answer
150 views

network namespace broken after exiting openvpn

I did these: ip netns add vpn ip netns exec vpn ip addr add 127.0.0.1/8 dev lo ip netns exec vpn ip link set lo up ip link add vpn0 type veth peer name vpn1 ip link set vpn0 up ip link set vpn1 ...
6
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1answer
6k views

Connecting two network namespaces via a veth interface pair where each endpoint has the same name

Is there a single (simple) command that will create a veth interface pair and assign each interface to a different network namespace? For example, suppose that I have two namespaces: mynamespace-1 ...
1
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2answers
3k views

Internet connectivity using linux network namespace

I experimenting with Linux namespaces on Ubuntu 17.1 distro. Ultimate goal is to force an application to use a particular network interface via a 3G modem not the intranet wired connection. My PC has ...
1
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0answers
116 views

Limit network interface to specific commands vice versa

I'm using this tutorial: Bind unix program to specific network interface Assume that $NS and $IN is set properly My problem I have two network interfaces and one of them has data limits and I don't ...
2
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0answers
312 views

stp is not working in network namespaces?

Why does the Linux bridge inside of netns sees bpdus but doesn't update topology? I've created a pair of netnses: NS300, NS301, a bridge in each one: br300, br301, a first veth link between the ...
3
votes
2answers
5k views

How to make reachable macvlan aliases in a different namespaces?

I have an interface, name eth0, in my main network namespace another interface, name jail0, in an alternate network namespace (name name0). This namespace is used by a jailed environment. jail0 is a ...
1
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2answers
655 views

NFS mount over network namespaces

Is it possible to use NFS over Linux network namespaces? Does it even make sense? The only related thing in kernel source I found is is commit 7e3fcf61abde nfs: don't share mounts between network ...
6
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2answers
4k views

How do I connect a veth device inside an 'anonymous' network namespace to one outside?

I have a process that has called unshare to create a new network namespace with just itself inside. When it calls execve to launch bash, the ip command shows that I have just an lo device. If I also ...
4
votes
1answer
8k views

How to forward traffic between Linux network namespaces?

I was able to set up a network namespace and start a server that listens on 127.0.0.1 inside the namespace: # ip netns add vpn # ip netns exec vpn ip link set dev lo up # ip netns exec vpn nc -l -s ...
1
vote
1answer
1k views

SNAT to unroutable interface

I set up a virtual ethernet (veth) pair between default namespace and another namespace named RoutableNS as follow: -------------- -------------- - veth0 - -------------- veth1 ...
1
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0answers
514 views

dnsmasq not available from network namespace at first

ubuntu 16.04, dnsmasq 2.75 NOTE: I have dnsmasq running with --hostsdir option so dnsmasq should pick up host entries written to that directory. Steps to reproduce: ... fresh machine boot ... $> ...
1
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1answer
126 views

Prevent application from using all IPs on port (0.0.0.0:34964)

I have two applications that use the same port for network communication (34964). I have control over (source code) the first application and it uses 192.168.0.4:34964. Whereas the other application ...
1
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1answer
2k views

Default kernel parameters on new network namespaces

What are the default kernel parameters, when creating a new network namespace? Is there a way to override them upon creation? I think they are inherited by the parent process. An example using ...
-2
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1answer
626 views

One public IP address per Namespace [closed]

How can I associate one public IP address per Namespace in my Ubuntu 14.04 server? I need to launch one specific process per Namespace then per public IP address. I want to do that: configuration: ...
1
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1answer
236 views

Network Namespace (non) Isolation?

I've been doing some research on Linux and networks in general, and came across namespaces. After reading articles and learning how to set one up, I am confused. I installed an application on my ...
1
vote
1answer
78 views

Networking issue communicating to Virtual Network on ubuntu 16.04

Using ubuntu 16.04. My goal is to run a small service inside of a network namespace(my-network) and communicate with that service from the host. I have created a linux bridge, a new network ...
0
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1answer
688 views

Network namespaces and scripts seem to break $PATH [duplicate]

Assume the following script: $ cat test.sh #!/bin/bash echo $PATH This happens: $ echo $PATH /usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/home/<user>/.local/bin:/home/<user>/bin $ ...
2
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2answers
4k views

Can OpenVPN create the default route if it doesn't exist?

Note This question was originally asked about OpenVPN not setting a default gateway if one did not already exist even if you specify --redirect-gateway local or --redirect-gateway def1. As of 2.4.1, ...
1
vote
1answer
2k views

How to specify a namespace when creating a tun/tap device?

On linux I can create a new tun/tap device in C using something like: int fd = open("/dev/net/tun", O_RDWR); ioctl(fd, TUNSETIFF, (void *)&ifr); This will create a new network interface in the ...
1
vote
1answer
736 views

Why remount of /proc/sys is not global or does not persist in network namespace inside LXC

I have host running RHEL-7.2. Inside that running LXC. Inside LXC creating network namespaces. Inside the namespace changing sysctl variables was failing (as root): $ ip netns add testns $ ip netns ...
5
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1answer
7k views

routing between linux namespaces

I have the following network topology using linux namespaces: .--------.veth0 .--------.veth2 .--------. | ns_snd |------------| ns_mid |------------| ns_rcv | '--------' veth1'-----...
1
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1answer
43 views

linux - context-based access control

I would like to further restrict network traffic based on the source / destination application. To do that, I'm using network namespaces, but is there a better / simpler approach? My approach ...
3
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2answers
4k views

remove link from Linux namespace

I created a namespace in Linux with 'ip netns add foo', created a pair of veth interfaces and moved one in the namespace. I set up IP addresses etc., so that now I can ping my 'foo' namespace from the ...
3
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0answers
1k views

Netlink access inside a network namespace

I'm trying set up an IPsec gateway (strongSwan) on a Raspberry Pi 2. The Pi was already providing a number of services on the LAN using a private IP address. My initial attempt to turn it into an ...
4
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0answers
878 views

How can I constrain a user application to always run in a particular network namespace?

I need to be able to constrain a user application to always run in a particular network namespace. Assume I have previously set up my network configuration as such: ip tuntap add name tap0 mode tap ...
2
votes
2answers
597 views

Starting isolated namespace inside network namespace

I've managed to create two network namespaces (ns1 and ns2) and connect them via veth connection. They can ping each other fine, and even ssh one into another (provided I started sshd). What I would ...
15
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4answers
10k views

port forwarding to application in network namespace with vpn

I was able to set up a network namespace, establish a tunnel with openvpn and start an application that uses this tunnel inside the namespace. So far so good, but this application can be accessed via ...
0
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1answer
528 views

How to add ovs interface back to init namespace from custom one?

Am creating an internal interface tap1 in ovs & add it to a custom namespace ns1. ip netns add ns1 ovs-vsctl --may-exist add-port br0 tap1 ip link set tap1 netns ns1 after am done using the ...