1. Prepojenie sieťového menného priestoru a hostiteľského systému - pomocou páru veth adaptérov
Anglická verzia tohto dokumentu: 1. Connecting a network namespace to the host system - with a veth pair.
2016 - Linux NET Namespace - Prepojenie sieťového menného priestoru a hostiteľského systému - pomocou páru veth adaptérov
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[1] NET namespace - Prepojenie sietoveho menneho priestoru a hostitelskeho systemu - pomocou paru veth adapterov
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+--------------------+ +--------------------+
| hostOS veth1.1 |=========kabel=========| veth1.2 ns1 | (PID = 2429)
+--------------------+ +--------------------+
hostitelsky system namespace "ns1"
[1.1] - Vytvorime jeden ("ns1") sietovy (NET) menny priestor.
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# ip netns add ns1
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[1.2]TERM2 - V sietovom mennom priestore "ns1" spustime (exec) prikaz "bash". PID = 2429
[1.3]TERM2 - Zistime PID BASH procesu.
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[1.2]TERM2# ip netns exec ns1 bash
[1.3]TERM2# echo $$
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2429
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[1.4] - Vytvorime par virtualnych Ethernet zariadeni, ktore budu predstavovat sietovy kabel s dvoma RJ45
koncovkami, pricom jednu stranu (veth1.2) pripojime do menneho priestoru "ns1" (na zaklade identifikatora
procesu [55718]) a druhu stranu (veth1.1) pripojime do hostitelskeho systemu.
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# ip link add veth1.1 type veth peer name veth1.2 netns 2429
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[1.5] - Overime vytvorenie parov virtualnych zariadeni z kroku [1.4].
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# ip link show
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1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT qlen 1000
link/ether 00:0c:29:9b:30:f4 brd ff:ff:ff:ff:ff:ff
3: veth1.1@if2: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT qlen 1000
link/ether 22:74:36:08:a3:e0 brd ff:ff:ff:ff:ff:ff link-netnsid 0
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[1.6] - Zapneme sietovy adapter "veth1.2" v mennom priestore "ns1" a nastavime na nom IP adresu "10.0.0.1".
[1.7] - Zapneme sietovy adapter "veth1.1" v hostitelskom systeme ako druhu stranu "kabla/koncovky" "veth1.2" a
nastavime na nom IP adresu "10.0.0.2".
[1.8] - Otestujeme sietovu komunikaciu medzi hostOS a sietovym mennym priestorom "ns1".
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[1.6]# ip netns exec ns1 ifconfig veth1.2 10.0.0.1/24 up
[1.7]# ifconfig veth1.1 10.0.0.2/24 up
[1.8]# ping 10.0.0.1
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64 bytes from 10.0.0.1: icmp_seq=1 ttl=64 time=0.075 ms
64 bytes from 10.0.0.1: icmp_seq=2 ttl=64 time=0.093 ms
...
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[1.9] - Zobrazime smerovaciu tabulku pre sietovy menny priestor "ns1".
[1.10] - Zobrazime zoznam sietovych adapterov/liniek pre sietovy menny priestor "ns1".
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[1.9] # ip netns exec ns1 route
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Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
10.0.0.0 0.0.0.0 255.255.255.0 U 0 0 0 veth1.2
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[1.10]# ip netns exec ns1 ip link
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1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN mode DEFAULT qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: veth1.2@if13: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT qlen 1000
link/ether 7e:d3:d9:0a:56:b4 brd ff:ff:ff:ff:ff:ff link-netnsid 0
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