NetworkNamespaces

Network NameSpaces

Network NameSpaces это способ виртуализации сетевого стека в Linux

В пределах одной физической ноды можно получить:

• отдельную таблицу маршрутизации
• отдельную arp-таблицу
• iptables
• виртуальные устройства или реальные со своими шейперами.

Простой пример

Вот простой роутрер (ноут), один линк через WiFi

ip link show

ip link show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN qlen 1000
    link/ether 00:1d:72:d2:2e:41 brd ff:ff:ff:ff:ff:ff
3: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
    link/ether 00:21:5d:40:2d:7a brd ff:ff:ff:ff:ff:ff
4: lxcbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN 
    link/ether 5a:c4:11:2e:48:99 brd ff:ff:ff:ff:ff:ff

(lxcbr0) - бридж для LXC, никак не мешает. Проверить наличие неймспейсов:

ip netns show

... ничего нет.
Добавляем 2 неймспейса

ip netns add R0
ip netns add R1

Проверяем:

ip netns list 
R1
R0

Добавляем 2 виртуальных линка (veth == virtual eth)

ip link add name ve0a type veth peer name ve0b
ip link add name ve1a type veth peer name ve1b

ip link show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN qlen 1000
    link/ether 00:1d:72:d2:2e:41 brd ff:ff:ff:ff:ff:ff
3: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
    link/ether 00:21:5d:40:2d:7a brd ff:ff:ff:ff:ff:ff
4: lxcbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN 
    link/ether 5a:c4:11:2e:48:99 brd ff:ff:ff:ff:ff:ff
20: ve0b: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
    link/ether 2e:0c:69:1a:43:d1 brd ff:ff:ff:ff:ff:ff
21: ve0a: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
    link/ether b2:21:f3:95:e3:f6 brd ff:ff:ff:ff:ff:ff
22: ve1b: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
    link/ether 16:a4:78:2e:1f:56 brd ff:ff:ff:ff:ff:ff
23: ve1a: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
    link/ether 2a:62:f9:4f:c1:6c brd ff:ff:ff:ff:ff:ff

Добавилось 4 виртуальных интерфейса или они же 2 виртуальных линка
Далее переносим виртуальные езернеты с индексом b внутрь name spaces

ip link set dev ve0b netns R0
ip link set dev ve1b netns R1

Как можно видеть ниже - интерфейсы перестали быть видны:

ip link show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN qlen 1000
    link/ether 00:1d:72:d2:2e:41 brd ff:ff:ff:ff:ff:ff
3: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
    link/ether 00:21:5d:40:2d:7a brd ff:ff:ff:ff:ff:ff
4: lxcbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN 
    link/ether 5a:c4:11:2e:48:99 brd ff:ff:ff:ff:ff:ff
21: ve0a: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
    link/ether b2:21:f3:95:e3:f6 brd ff:ff:ff:ff:ff:ff
23: ve1a: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
    link/ether 2a:62:f9:4f:c1:6c brd ff:ff:ff:ff:ff:ff

ip netns exec R0  ip link show
ip netns exec R1  ip link show
ip netns exec R0  ip addr add 172.19.0.1/24 dev ve0b
ip netns exec R1  ip addr add 172.20.0.1/24 dev ve1b

ip netns exec R0  ip link set up dev ve0b
ip netns exec R1  ip link set up dev ve1b

ip netns exec R0 ifconfig 
ip netns exec R1 ifconfig 
<PRE>

<PRE>
ip addr add 172.19.0.2/24 dev ve0a
ip addr add 172.20.0.2/24 dev ve1a
ip link set up dev ve0a
ip link set up dev ve1a

Связанные темы

http://wiki.sirmax.noname.com.ua/index.php/LXC