net namespace experiment

Others 2019-07-26 17:14:04 views: null

Net namespace experiment

In Linux, network namespace can be considered an isolated network stack has a separate (NIC, routing forwarding, iptables) environment. Network name space is often used to isolate network equipment and services, only to have the same network device name space, to see each other. network namespace is an important feature for network virtualization, it can create multiple isolated cyberspace, they alone have the network stack information. Whether virtual machines or containers, when running as if in their own separate network

Common Commands

comm command
ip netns add net1 Add namespace net1
ip netns help Getting Help
ip netns del n1 Delete namespace n1
ip netns ls It lists the current existing namespace

NET namespace associated with the instruction is ip netnsfollowed by specific instructions
using the ip netns exec namesubcommand any command can be added later, it represents the corresponding command is executed in the namespace, such as:

root@mininet-vm:/home/mininet# ip netns exec n2 ip addr
1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN group default 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00

It can be performed ip netns exec n2 bashafter all instructions are executed without the need to add a specified namespace inip netns exec name

root@mininet-vm:/home/mininet# ip netns exec n2 ip addr
1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN group default 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
root@mininet-vm:/home/mininet# ip netns exec n2 bash
root@mininet-vm:/home/mininet# ip addr
1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN group default 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
root@mininet-vm:/home/mininet# exit
exit
root@mininet-vm:/home/mininet# ip addr
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 pfifo_fast 
.................

Use ip netns exec n2 bash --rcfile <(echo "PS1=\"namespace ns1>\"")can modify the prefix of the command line.

root@mininet-vm:/home/mininet# ip netns exec n2 bash --rcfile <(echo "PS1=\"namespace n2>\"")
namespace n2>

　namespace communication

Veth pair communicate using

  1. Creating a pair veth pair
    using the command ip link add type vethcreates a pair of veth pair, whose default name is veth0 and veth1, use ip linkto view links
   root@mininet-vm:/home/mininet# ip link
.....
3: ovs-system: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN 
root@mininet-vm:/home/mininet # ip link add type veth
root@mininet-vm:/home/mininet # ip link
....
3: ovs-system: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN 
9: veth0@veth1: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
    link/ether 12:e8:a5:43:c0:43 brd ff:ff:ff:ff:ff:ff
10: veth1@veth0: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
    link/ether 9e:f8:c3:b9:af:ec brd ff:ff:ff:ff:ff:ff
  1. The ends veth pair respectively into two namespace
    using the command ip link set veth0 netns n1and ip link set veth1 netns n2respectively into different namespace veth0 and veth1
oot@mininet-vm:/home/mininet# ip link set veth0 netns n1
root@mininet-vm:/home/mininet# ip link set veth1 netns n2
root@mininet-vm:/home/mininet# ip netns exec n1 ip addr
1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN group default 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
9: veth0@if10: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 12:e8:a5:43:c0:43 brd ff:ff:ff:ff:ff:ff
root@mininet-vm:/home/mininet# ip netns exec n2 ip addr
1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN group default 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
10: veth1@if9: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 9e:f8:c3:b9:af:ec brd ff:ff:ff:ff:ff:ff
  1. Both ends veth pair are arranged ip
    using the command ip link set vethX upand ip addr add 10.0.0.10/24 dev vethXto the ip veth pair, the following results
# namespace 1
namespace ns1> ip link set veth0 up
namespace ns1> ip a
1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN group default 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
9: veth0@if10: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 12:e8:a5:43:c0:43 brd ff:ff:ff:ff:ff:ff
namespace ns1> ip addr add 10.0.10.1/24 dev veth0
namespace ns1> ip a
1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN group default 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
9: veth0@if10: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 12:e8:a5:43:c0:43 brd ff:ff:ff:ff:ff:ff
    inet 10.0.10.x1/24 scope global veth0
       valid_lft forever preferred_lft forever

# namespace 2
namespace n2>ip link set veth1 up
namespace n2>ip addr add 10.0.10/24 dev veth1
namespace n2>ip a
1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN group default 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
10: veth1@if9: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state LOWERLAYERDOWN group default qlen 1000
link/ether 9e:f8:c3:b9:af:ec brd ff:ff:ff:ff:ff:ff
    inet 10.0.10.0/24 scope global veth1
       valid_lft forever preferred_lft forever
  1. Test network connectivity status between two namespace
    are ping attempts in the n1 and n2
namespace ns1> ping 10.0.10.0 -c 1
PING 10.0.10.0 (10.0.10.0) 56(84) bytes of data.
64 bytes from 10.0.10.0: icmp_seq=1 ttl=64 time=0.035 ms
namespace n2>ping 10.0.10.1 -c 1
PING 10.0.10.1 (10.0.10.1) 56(84) bytes of data.
64 bytes from 10.0.10.1: icmp_seq=1 ttl=64 time=0.040 ms

  1. The topology follows
    20190725185608.png
    veth pair may be used for communication between two namespace, but is not suitable for use in the passage between the plurality namespace

    Use bridge communication

  2. In the above experimental basis, re-create the two namespace: n3, n4
root@mininet-vm:/home/mininet# ip netns add n3
root@mininet-vm:/home/mininet# ip netns add n4
root@mininet-vm:/home/mininet# ip netns ls
n4
n3
n1
n2
  1. Create a bridge
root@mininet-vm:/home/mininet# ip link add br0 type bridge
root@mininet-vm:/home/mininet# 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 pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:1e:27:79 brd ff:ff:ff:ff:ff:ff
    inet 192.168.117.128/24 brd 192.168.117.255 scope global eth0
       valid_lft forever preferred_lft forever
3: ovs-system: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default 
    link/ether 72:f5:e5:5d:4d:ed brd ff:ff:ff:ff:ff:ff
11: br0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default 
    link/ether 76:d8:06:1a:b9:84 brd ff:ff:ff:ff:ff:ff
  1. Veth pair using the bridge and n3, n4, n1 communication
    create three pairs veth pair
root@mininet-vm:/home/mininet# ip link add type veth
root@mininet-vm:/home/mininet# ip link add type veth
root@mininet-vm:/home/mininet# ip link add type veth
root@mininet-vm:/home/mininet# ip a
...
11: br0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default 
    link/ether 76:d8:06:1a:b9:84 brd ff:ff:ff:ff:ff:ff
12: veth0@veth1: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether ea:98:b6:3c:46:60 brd ff:ff:ff:ff:ff:ff
13: veth1@veth0: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether f2:f6:d8:6b:31:1f brd ff:ff:ff:ff:ff:ff
14: veth2@veth3: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 4a:7d:af:18:67:14 brd ff:ff:ff:ff:ff:ff
15: veth3@veth2: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether ca:b6:e4:eb:b7:15 brd ff:ff:ff:ff:ff:ff
16: veth4@veth5: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether f2:b3:5f:0e:3d:09 brd ff:ff:ff:ff:ff:ff
17: veth5@veth4: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 76:0c:87:b1:16:80 brd ff:ff:ff:ff:ff:ff

The br0 and n1, n3, n4 connection
at this time if the veth0 join n1, then will complain, because there has been a veth0 n1, veth can be replaced with other names.
The discharge veth pair of instructions as br0ip link set dev veth3 master br0

  1. The communication state between the test n1-n4
    ping operation fails different namespace.
    Toss this problem for a long time, then there are more than a few times to configure it. It should be before missing a few steps, complete steps should include the following steps:

    # 启动网桥（网桥只需要启动一次就行）
ip link set br0 up
# 创建vethpair
ip link add br-1 type veth peer name 1-br
#将vethpair分配给网桥和namespace
ip link set br-1 master br0
ip link set 1-br netns n1
#启动veth
ip link set br-1 up
ip netns exec n1 ip link set 1-br up
# 为namespace中的veth设置ip
  ip netns exec n1 ip addr add 10.0.10.2/24 dev 1-br

    Re-tested and found three namespace can ping each other.

ip corresponding to the above-described bridge veth fact be omitted

  1. The topology below

    ### internal namespace namespace external communication with
    default, the network namespace are isolated, not ping network outside the namespace namespace, can get through the network status veth pair.
    When veth pair within the namespace end, at one end of the external namespace, namespace can ping veth pair located outside but can not ping with other networks.

    Reference material

    https://cizixs.com/2017/02/10/network-virtualization-network-namespace/

Guess you like

Origin www.cnblogs.com/yezhh/p/11248897.html
Recommended
Ranking
#2019110700005
What materials and procedures are required for patent transfer
What is the blockchain Ethereum triplet state root transaction root receipt root
Front-end study notes 04 --- About the insertion of html pictures and videos
Documents required for the filing of WeChat Mini Programs in special industries, the filing process of WeChat Mini Programs in special industries, how to file WeChat Mini Programs in special industries
2017 Qingdao-site tournament I The Squared Mosquito Coil
[BZOJ3165][HEOI2013]Segment (line segment tree without marking)
Kettle series: KettleEasyExpand, an open source Kettle universal plugin by Ma Jinju
The latest tutorial on making framework for iOS
DAX Section 6: Statistical Functions
Daily
More
2024-05-14(9)
2024-05-13(8)
2024-05-12(28)
2024-05-11(32)
2024-05-10(34)
2024-05-09(32)
2024-05-08(18)
2024-05-07(34)
2024-05-06(6)
2024-05-05(0)

Code World

© 2018 codetd.com