Cara Mengonfigurasi Teaming Antarmuka Jaringan di CentOS/RHEL 7 dan 8

Tim antarmuka jaringan diperkenalkan dari CentOS/RHEL 7 sebagai alternatif yang lebih dapat diperluas dan skalabel untuk ikatan jaringan. Postingan ini menjelaskan cara mengonfigurasi kerja sama jaringan di CentOS/RHEL 7/8.

Contoh yang diberikan didasarkan pada sistem Oracle Linux 8.2 (mesin virtual tamu Oracle VirtualBox 6.1) dengan dua antarmuka jaringan menggunakan NetworkManager.
Secara khusus, Antarmuka Baris Perintah Manajer Jaringan (nmcli) terutama digunakan dengan opsi yang ditentukan dalam disingkat/dipendekkan formulir.

1. Konfigurasi Pra-Tim Asli

Berikut ini menunjukkan konfigurasi jaringan pra-tim asli:

# dnf list | grep team | grep anaconda
NetworkManager-team.x86_64        1:1.22.8-4.el8                 @anaconda
libteam.x86_64                    1.29-1.el8                     @anaconda
teamd.x86_64                      1.29-1.el8                     @anaconda

# lspci | grep -i eth
00:03.0 Ethernet controller: Intel Corporation 82540EM Gigabit Ethernet Controller (rev 02)
00:08.0 Ethernet controller: Intel Corporation 82540EM Gigabit Ethernet Controller (rev 02)

# nmcli dev
DEVICE  TYPE      STATE      CONNECTION
enp0s3  ethernet  connected  enp0s3
enp0s8  ethernet  connected  enp0s8
lo      loopback  unmanaged  --

# nmcli con
NAME    UUID                                  TYPE      DEVICE
enp0s3  XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX  ethernet  enp0s3
enp0s8  XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX  ethernet  enp0s8

# ls -l /etc/sysconfig/network-scripts/*
-rw-r--r-- 1 root root 334 Aug 21 13:29 /etc/sysconfig/network-scripts/ifcfg-enp0s3
-rw-r--r-- 1 root root 334 Aug 21 13:30 /etc/sysconfig/network-scripts/ifcfg-enp0s8

# cat /etc/sysconfig/network-scripts/ifcfg-enp0s3
  1 MACADDR=[MAC_ADDR1]
  2 MTU=1500
  3 TYPE=Ethernet
  4 PROXY_METHOD=none
  5 BROWSER_ONLY=no
  6 BOOTPROTO=dhcp
  7 DEFROUTE=yes
  8 IPV4_FAILURE_FATAL=no
  9 IPV6INIT=yes
  10 IPV6_AUTOCONF=yes
  11 IPV6_DEFROUTE=yes
  12 IPV6_FAILURE_FATAL=no
  13 IPV6_ADDR_GEN_MODE=stable-privacy
  14 NAME="enp0s3"
  15 UUID=XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
  16 DEVICE=enp0s3
  17 ONBOOT=yes

# cat /etc/sysconfig/network-scripts/ifcfg-enp0s8
  1 MACADDR=[MAC_ADDR2]
  2 MTU=1500
  3 TYPE=Ethernet
  4 PROXY_METHOD=none
  5 BROWSER_ONLY=no
  6 BOOTPROTO=dhcp
  7 DEFROUTE=yes
  8 IPV4_FAILURE_FATAL=no
  9 IPV6INIT=yes
  10 IPV6_AUTOCONF=yes
  11 IPV6_DEFROUTE=yes
  12 IPV6_FAILURE_FATAL=no
  13 IPV6_ADDR_GEN_MODE=stable-privacy
  14 NAME="enp0s8"
  15 UUID=XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
  16 DEVICE=enp0s8
  17 ONBOOT=yes

# ip addr
...
2: enp0s3:  mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether  brd ff:ff:ff:ff:ff:ff
    inet /24 brd  scope global dynamic noprefixroute enp0s3
       valid_lft 86059sec preferred_lft 86059sec
    inet6 fe80::ca99:46d3:1765:f02b/64 scope link noprefixroute
       valid_lft forever preferred_lft forever
3: enp0s8:  mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether  brd ff:ff:ff:ff:ff:ff
    inet /24 brd  scope global dynamic noprefixroute enp0s8
       valid_lft 86121sec preferred_lft 86121sec
    inet6 fe80::36d0:6bd3:5152:83dc/64 scope link noprefixroute
       valid_lft forever preferred_lft forever

2. Hapus koneksi jaringan yang ada

Hapus koneksi enp0s3 dan enp0s8 yang ada sebagai berikut. Ini dibuat kembali sebagai budak tim dalam langkah-langkah berikut.

# nmcli con show
NAME    UUID                                  TYPE      DEVICE
enp0s3  XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX  ethernet  enp0s3
enp0s8  XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX  ethernet  enp0s8

# nmcli con del XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
Connection 'enp0s3' (XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX) successfully deleted.
# nmcli con del XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
Connection 'enp0s8' (XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX) successfully deleted.

# nmcli dev
DEVICE  TYPE      STATE         CONNECTION
enp0s3  ethernet  disconnected  --
enp0s8  ethernet  disconnected  --
lo      loopback  unmanaged     --

# ls -l /etc/sysconfig/network-scripts/
total 0
#

3. Buat koneksi tim master

Buat koneksi tim master. Misalnya:

# nmcli con add type team con-name team0 ifname team0 config '{"runner": {"name": "activebackup"}, "link_watch": {"name": "ethtool"}}'
Connection 'team0' (XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX) successfully added.

Di atas, mode team running (runner) adalah activebackup dan team link monitor/watcher (link_watch) adalah ethtool. Nilai pelari alternatif dan link_watch meliputi:

• pelari :loadbalance, roundrobin, lap, broadcast, random.
• link_watch :arp_ping, nsna_ping

NetworkManager membuat file konfigurasi antarmuka berikut:

# cat /etc/sysconfig/network-scripts/ifcfg-team0
  1 TEAM_CONFIG="{\"runner\": {\"name\": \"activebackup\"}, \"link_watch\": {\"name\": \"ethtool\"}}"
  2 PROXY_METHOD=none
  3 BROWSER_ONLY=no
  4 BOOTPROTO=dhcp
  5 DEFROUTE=yes
  6 IPV4_FAILURE_FATAL=no
  7 IPV6INIT=yes
  8 IPV6_AUTOCONF=yes
  9 IPV6_DEFROUTE=yes
 10 IPV6_FAILURE_FATAL=no
 11 IPV6_ADDR_GEN_MODE=stable-privacy
 12 NAME=team0
 13 UUID=XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
 14 DEVICE=team0
 15 ONBOOT=yes
 16 DEVICETYPE=Team

# nmcli con
NAME   UUID                                  TYPE  DEVICE
team0  XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX  team  team0

# nmcli dev
DEVICE  TYPE      STATE                                  CONNECTION
team0   team      connecting (getting IP configuration)  team0
enp0s3  ethernet  disconnected                           --
enp0s8  ethernet  disconnected                           --
lo      loopback  unmanaged

4. Secara opsional, tetapkan alamat IP statis ke tim

Secara opsional, tetapkan alamat IP statis, gateway, DNS, dll. ke koneksi tim. Misalnya:

# nmcli con mod team0 ipv4.addresses [IP3]/24
# nmcli con mod team0 ipv4.gateway [IP4]
# nmcli con mod team0 ipv4.dns [IP5]
# nmcli con mod team0 ipv4.method manual
# nmcli con mod team0 connection.autoconnect yes

NetworkManager memodifikasi file konfigurasi antarmuka tim berikut:

# cat /etc/sysconfig/network-scripts/ifcfg-team0
  1 TEAM_CONFIG="{\"runner\": {\"name\": \"activebackup\"}, \"link_watch\": {\"name\": \"ethtool\"}}"
  2 PROXY_METHOD=none
  3 BROWSER_ONLY=no
  4 BOOTPROTO=none
  5 DEFROUTE=yes
  6 IPV4_FAILURE_FATAL=no
  7 IPV6INIT=yes
  8 IPV6_AUTOCONF=yes
  9 IPV6_DEFROUTE=yes
 10 IPV6_FAILURE_FATAL=no
 11 IPV6_ADDR_GEN_MODE=stable-privacy
 12 NAME=team0
 13 UUID=XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
 14 DEVICE=team0
 15 ONBOOT=yes
 16 DEVICETYPE=Team
 17 IPADDR=[IP3]
 18 PREFIX=24
 19 GATEWAY=[IP4]
 20 DNS1=[IP5]

Tim akan menggunakan DHCP jika tidak ada alamat IP statis yang ditetapkan.

5. Konfigurasi dan tambahkan budak ke tim

Konfigurasi dan tambahkan budak ke tim. Misalnya:

# nmcli con add type team-slave con-name team0-slave0 ifname enp0s3 master team0
Connection 'team0-slave0' (XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX) successfully added.
# nmcli con add type team-slave con-name team0-slave1 ifname enp0s8 master team0
Connection 'team0-slave1' (XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX) successfully added.

# nmcli conn
NAME          UUID                                  TYPE      DEVICE
team0         XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX  team      team0
team0-slave0  XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX  ethernet  enp0s3
team0-slave1  XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX  ethernet  enp0s8

# nmcli dev
DEVICE  TYPE      STATE      CONNECTION
team0   team      connected  team0
enp0s3  ethernet  connected  team0-slave0
enp0s8  ethernet  connected  team0-slave1
lo      loopback  unmanaged  --

NetworkManager membuat file konfigurasi antarmuka budak tim berikut:

# cat /etc/sysconfig/network-scripts/ifcfg-team0-slave0
  1 NAME=team0-slave0
  2 UUID=XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
  3 DEVICE=enp0s3
  4 ONBOOT=yes
  5 TEAM_MASTER=team0
  6 DEVICETYPE=TeamPort

# cat /etc/sysconfig/network-scripts/ifcfg-team0-slave1
  1 NAME=team0-slave1
  2 UUID=XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
  3 DEVICE=enp0s8
  4 ONBOOT=yes
  5 TEAM_MASTER=team0
  6 DEVICETYPE=TeamPort

Ketika setidaknya satu budak ditambahkan ke tim, antarmuka (tim0) dibawa dan dapat diakses.

# ip addr
...
2: enp0s3: [BROADCAST,MULTICAST,UP,LOWER_UP] mtu 1500 qdisc fq_codel master team0 state UP group default qlen 1000
    link/ether [MAC1] brd ff:ff:ff:ff:ff:ff
3: enp0s8: [BROADCAST,MULTICAST,UP,LOWER_UP] mtu 1500 qdisc fq_codel master team0 state UP group default qlen 1000
    link/ether [MAC1] brd ff:ff:ff:ff:ff:ff
6: team0: [BROADCAST,MULTICAST,UP,LOWER_UP] mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether [MAC1] brd ff:ff:ff:ff:ff:ff
    inet [IP3]/24 brd [IP6] scope global dynamic noprefixroute team0
       valid_lft 86045sec preferred_lft 86045sec
    inet6 fe80::5b1f:554a:1928:8575/64 scope link noprefixroute
       valid_lft forever preferred_lft forever

Perhatikan bahwa semua antarmuka tim/tim menggunakan alamat MAC yang sama yaitu alamat MAC dari anggota slave tim pertama.

6. Mulai ulang tim

Mulai ulang tim agar alamat IP statis, dll. diterapkan. Misalnya:

# nmcli con down team0 && nmcli con up team0

7. Identifikasi antarmuka budak aktif/tidak aktif saat ini

Identifikasi antarmuka budak aktif dan tidak aktif saat ini menggunakan teamdctl(8). Misalnya:

# teamdctl team0 state
setup:
  runner: activebackup
ports:
  enp0s3
    link watches:
      link summary: up
      instance[link_watch_0]:
        name: ethtool
        link: up
        down count: 0
  enp0s8
    link watches:
      link summary: up
      instance[link_watch_0]:
        name: ethtool
        link: up
        down count: 0
runner:
  active port: enp0s3

8. Aktifkan mode promiscuous untuk antarmuka jaringan

Beberapa teknologi virtualisasi, seperti Oracle VM VirtualBox, memerlukan mode promiscuous untuk diaktifkan pada antarmuka jaringan yang ditetapkan untuk tamu, serta di dalam tamu agar failover/failback slave berperilaku dengan benar. Mengaktifkan mode promiscuous pada antarmuka jaringan pada sistem fisik juga mungkin diperlukan.

Untuk Oracle VM VirtualBox, mode promiscuous dapat diaktifkan untuk antarmuka tamu sebagai berikut:
– Oracle VM VirtualBox Manager> [GUEST]> Settings> Network> Adapter 1|… ] Advanced ] Promiscuous Mode:Allow All

Mode promiscuous dapat diaktifkan dalam sistem CentOS/RHEL 7 secara dinamis dan statis menggunakan layanan kustom sebagai berikut:

Dinamis, tidak persisten:

# ip link set enp0s3 promisc on
# ip link set enp0s8 promisc on

Statis, persisten:

Buat file unit sistem khusus dengan konten berikut, mis.:

# cat /usr/lib/systemd/system/promiscuous.service
  1 [Unit]
  2 Description=Bring up network interfaces in promiscuous mode upon boot
  3 After=network.target
  4
  5 [Service]
  6 Type=oneshot
  7 ExecStart=/usr/sbin/ip link set dev enp0s3 promisc on
  8 ExecStart=/usr/sbin/ip link set dev enp0s8 promisc on
  9 ExecStop=/usr/sbin/ip link set dev enp0s3 promisc off
 10 ExecStop=/usr/sbin/ip link set dev enp0s8 promisc off
 11 TimeoutStartSec=0
 12 RemainAfterExit=yes
 13
 14 [Install]
 15 WantedBy=default.target

Beri tahu systemd tentang layanan baru. Misalnya:

# systemctl daemon-reload

Aktifkan dan mulai layanan/unit baru mis.:

# systemctl enable promiscuous
Created symlink /etc/systemd/system/default.target.wants/promiscuous.service → /usr/lib/systemd/system/promiscuous.service.

# systemctl start promiscuous

# systemctl status promiscuous
● promiscuous.service - Bring up network interfaces in promiscuous mode upon boot
   Loaded: loaded (/usr/lib/systemd/system/promiscuous.service; enabled; vendor preset: disabled)
   Active: active (exited) since Fri 2020-08-21 16:14:53 AEST; 17s ago
  Process: 8088 ExecStart=/usr/sbin/ip link set dev enp0s8 promisc on (code=exited, status=0/SUCCESS)
  Process: 8086 ExecStart=/usr/sbin/ip link set dev enp0s3 promisc on (code=exited, status=0/SUCCESS)
 Main PID: 8088 (code=exited, status=0/SUCCESS)

Aug 21 16:14:53 [HOST] systemd[1]: Starting Bring up network interfaces in promiscuous mode upon boot...
Aug 21 16:14:53 [HOST] systemd[1]: Started Bring up network interfaces in promiscuous mode upon boot.

Pastikan mode promiscuous diaktifkan pada semua antarmuka budak. Misalnya:

# ip addr | grep enp
2: enp0s3: [BROADCAST,MULTICAST,PROMISC,UP,LOWER_UP] mtu 1500 qdisc fq_codel master team0 state UP group default qlen 1000
3: enp0s8: [BROADCAST,MULTICAST,PROMISC,UP,LOWER_UP] mtu 1500 qdisc fq_codel master team0 state UP group default qlen 1000

9. Menguji ketahanan konektivitas jaringan Tim – failover/failback slave

A. Dari klien jarak jauh, mulai ping terus menerus (8) dari server yang jaringannya telah dikonfigurasi, mis.:

[CLIENT]$ ping [SERVER]
PING [IP3] ([IP3]) 56(84) bytes of data.
64 bytes from [IP3]: icmp_seq=1 ttl=64 time=0.025 ms
64 bytes from [IP3]: icmp_seq=2 ttl=64 time=0.034 ms
64 bytes from [IP3]: icmp_seq=3 ttl=64 time=0.039 ms
...

B. Putuskan koneksi budak tim yang sedang aktif.

Putuskan sementara kabel jaringan fisik yang terhubung ke antarmuka slave mis. enp0s3. Perhatikan bahwa menonaktifkan antarmuka secara terprogram tidak meniru hilangnya konektivitas tautan fisik yang sebenarnya.

# teamdctl team0 state
setup:
  runner: activebackup
ports:
  enp0s3
    link watches:
      link summary: down
      instance[link_watch_0]:
        name: ethtool
        link: down
        down count: 1
  enp0s8
    link watches:
      link summary: up
      instance[link_watch_0]:
        name: ethtool
        link: up
        down count: 0
runner:
  active port: enp0s8

Setelah terputus, teamdctl menunjukkan antarmuka budak enp0s3 sebagai down dan mantan budak cadangan enp0s8 sekarang menjadi budak aktif saat ini. Meskipun slave failover, ping(8) dari klien jarak jauh terus berlanjut tanpa gangguan.

Menjalankan perintah ip(8) selanjutnya mengkonfirmasi semua lalu lintas jaringan ke tim terjadi melalui budak aktif baru enp0s8 yaitu:

# ip -s link
...
2: enp0s3: [BROADCAST,MULTICAST,PROMISC] mtu 1500 qdisc fq_codel master team0 state DOWN mode DEFAULT group default qlen 1000
    link/ether [MAC1] brd ff:ff:ff:ff:ff:ff
    RX:  bytes packets  errors  dropped overrun mcast
    3007606561 5014092  0       27008   0       91263
    TX: bytes  packets  errors  dropped carrier collsns
    787749     7568     0       0       0       0
3: enp0s8: [BROADCAST,MULTICAST,PROMISC,UP,LOWER_UP] mtu 1500 qdisc fq_codel master team0 state UP mode DEFAULT group default qlen 1000
    link/ether [MAC1] brd ff:ff:ff:ff:ff:ff
    RX: bytes  packets  errors dropped overrun mcast
    3829373093 6116137  0      26680   0       111948
    TX: bytes  packets  errors dropped carrier collsns
    179163     1337     0      0       0       0
7: team0: [BROADCAST,MULTICAST,UP,LOWER_UP] mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether [MAC1] brd ff:ff:ff:ff:ff:ff
    RX: bytes  packets  errors dropped overrun mcast
    2106463511 1969187  0      49615   0       60559
    TX: bytes  packets  errors dropped carrier collsns
    176341     1378     0      0       0       0

C. Putuskan hubungan budak tim baru yang aktif saat ini.

Putuskan sementara kabel jaringan fisik yang terhubung ke antarmuka slave aktif yang baru dipromosikan, mis. enp0s8. Setelah terputus, teamdctl menunjukkan kedua antarmuka slave enp0s3 dan enp0s8 sebagai down yaitu:

# teamdctl team0 state
setup:
  runner: activebackup
ports:
  enp0s3
    link watches:
      link summary: down
      instance[link_watch_0]:
        name: ethtool
        link: down
        down count: 1
  enp0s8
    link watches:
      link summary: down
      instance[link_watch_0]:
        name: ethtool
        link: up
        down count: 1
runner:
  active port:

Pada titik ini, dengan kedua budak tim terputus, ping(8) dari klien jarak jauh berhenti mis.

...
64 bytes from [IP3]: icmp_seq=1253 ttl=64 time=0.207 ms
64 bytes from [IP3]: icmp_seq=1254 ttl=64 time=0.131 ms
64 bytes from [IP3]: icmp_seq=1255 ttl=64 time=0.227 ms
64 bytes from [IP3]: icmp_seq=1256 ttl=64 time=0.218 ms
64 bytes from [IP3]: icmp_seq=1257 ttl=64 time=0.198 ms
From [IP3] icmp_seq=1258 Destination Host Unreachable
From [IP3] icmp_seq=1259 Destination Host Unreachable
...

D. Hubungkan kembali slave yang terputus

Sambungkan kembali kabel jaringan fisik ke salah satu antarmuka slave mis. enp0s3. Setelah terhubung kembali, teamdctl menunjukkan antarmuka budak enp0s3 sebagai up yaitu:

# teamdctl team0 state
setup:
  runner: activebackup
ports:
  enp0s3
    link watches:
    link summary: up
      instance[link_watch_0]:
      name: ethtool
      link: up
      down count: 1
  enp0s8
    link watches:
    link summary: down
      instance[link_watch_0]:
      name: ethtool
      link: down
      down count: 1
runner:
  active port: enp0s3

Pada titik ini, dengan enp0s3 budak aktif saat ini, ping(8) dari klien jarak jauh dilanjutkan mis.

...
From [IP3] icmp_seq=1392 Destination Host Unreachable
From [IP3] icmp_seq=1393 Destination Host Unreachable
From [IP3] icmp_seq=1394 Destination Host Unreachable
From [IP3] icmp_seq=1395 Destination Host Unreachable
64 bytes from [IP3]: icmp_seq=1396 ttl=64 time=1258180 ms
64 bytes from [IP3]: icmp_seq=1397 ttl=64 time=1257180 ms
64 bytes from [IP3]: icmp_seq=1398 ttl=64 time=1256181 ms
64 bytes from [IP3]: icmp_seq=1399 ttl=64 time=1255181 ms
...

E. Hubungkan kembali budak yang tersisa yang terputus.

Sambungkan kembali kabel jaringan fisik ke antarmuka slave yang tersisa, mis. enp0s8. Setelah terhubung kembali, teamdctl menunjukkan antarmuka budak yang tersisa enp0s8 sebagai up yaitu:

# teamdctl team0 state
setup:
  runner: activebackup
ports:
  enp0s3
    link watches:
      link summary: up
      instance[link_watch_0]:
        name: ethtool
        link: up
        down count: 1
  enp0s8
    link watches:
      link summary: up
      instance[link_watch_0]:
        name: ethtool
        link: up
        down count: 1
runner:
  active port: enp0s3