LACP kasutamine

Allikas: Kuutõrvaja

Sissejuhatus

Ethernet interface bonding tehnika võimaldab teatud tingimustel kasutada mitut arvutisse paigaldatud füüsilist võrguseadet ühe loogilise seadmena.

TODO - Alljärgnev tõlkida ära.

The reason you dont get a throughput greater than 943Mbps is due to the way that link aggregation (LACP) works.

When you aggregate two links using LACP eg. 2 x 1G you dont get a 1 x 2G link; you get one link of 2 x 1G. This means that a connection between two hosts can never use more than 1G, but if you have two connections you might be able to use 2 x 1G; if they choose to use different links in the LACP link (this is based on some calculation using eg. IP address, mac address etc.). In other words, a connection between two hosts, can never use more bandwidth than the original links bandwidth.

It's just not possible to make 1 x 2 Gbps link using 2 x 1 Gbps links using LACP. The reason is, that when a host sends data using a LACP link, it determines which interface (link) to use by calculating a hash value based on a combination of L2 and L3 information. So if you have two hosts you will get the same hash value each time since the source/destination mac/IP addresses don't change, and the sending host will send data using only one (the same) link/interface. If the sending host is sending data to two different hosts, you might be lucky, that the hash value for the two receiving hosts matches each of the links on the sending hosts, thereby sending data on both links/interfaces.

Tööpõhimõte

TODO

Lacp-1.gif

SLM2008 lüliti

TODO

Lacp-2.gif

Debian GNU/Linux

Tarkvara paigaldamine

Vajalik tarkvara sisaldub operatsioonisüsteemi tuumas, juhtprogrammi ifenslave paigaldamiseks sobib öelda 

# apt-get install ifenslave-2.6

Seadistamine

Bonding seadme nimeks on tavaliselt bond0 ning LACP bonding (mitte segi ajada failover-bond seadmega) seadistatakse /etc/network/interfaces sektsiooniga 

auto bond0
iface bond0 inet static
  address 10.0.3.87
  netmask 255.255.255.0
  slaves eth1 eth2
  bond_mode 802.3ad
  bond_miimon 100
  bond-lacp-rate 4

Erinevate olekute tähendused

  • Round Robin - Packets are transmitted in a round robin fashion over the available slave interfaces. Provides both load balancing and fault tolerance
  • Active Backup - One slave interface is active at any time. If one interface fails, another interface takes over the MAC address and becomes the active interface. Provides fault tolerance only. Doesn't require special switch support
  • Balance XOR - Tranmissions are balanced across the slave interfaces based on ((source MAC) XOR (dest MAC)) modula slave count. The same slave is selected for each destination MAC. Provides load balancing and fault tolerance.
  • Broadcast - Transmits everything on all slave interfaces. Provides fault tolerance.
  • 802.3ad - This is classic IEEE 802.3ad Dynamic link aggregation. This requires 802.3ad support in the switch and driver support for retrieving the speed and duplex of each slave.
  • Balance TLB - Adaptive Transmit Load Balancing. Incoming traffic is received on the active slave only, outgoing traffic is distributed according to the current load on each slave. Doesn't require special switch support
  • Balance ALB - Adaptive Load Balancing - provides both transmit load balancing (TLB) and receive load balancing for IPv4 via ARP negotiation. Doesn't require special switch support, but does require the ability to change the MAC address of a device while it is open

Vaikimisi on balance-rr (round robin) ehk 0.

Vastav seadistamine käsurealt võiks toimuda nt selliselt 

 # modprobe bonding mode=802.3ad lacp_rate=1 miimon=100 xmit_hash_policy=layer3+4
 # ifconfig bond0 10.0.3.87 netmask 255.255.0.0
 # ifenslave bond0 eth1 eth2

Bonding seadme eemaldamiseks sobib öelda 

# ifenslave -d bond0 eth1 eth2
# rmmod bonding

Bonding seadme omadusi saab vaadata 

# cat /proc/net/bonding/bond0 
Ethernet Channel Bonding Driver: v3.2.5 (March 21, 2008)

Bonding Mode: IEEE 802.3ad Dynamic link aggregation
Transmit Hash Policy: layer3+4 (1)
MII Status: up
MII Polling Interval (ms): 100
Up Delay (ms): 0
Down Delay (ms): 0

802.3ad info
LACP rate: fast
Active Aggregator Info:
        Aggregator ID: 1
        Number of ports: 2
        Actor Key: 17
        Partner Key: 3
        Partner Mac Address: a8:b1:d4:95:a3:85

Slave Interface: eth1
MII Status: up
Link Failure Count: 0
Permanent HW addr: 00:0e:0c:ba:4b:3e
Aggregator ID: 1

Slave Interface: eth2
MII Status: up
Link Failure Count: 4
Permanent HW addr: 00:1b:21:1d:f6:06
Aggregator ID: 1

kus

  • Bonding Mode: IEEE 802.3ad Dynamic link aggregation - kasutusel olev bonding režiim

Kasutamine

TODO

OpenBSD

LACP seadme moodustamiseks sobib öelda nt 

# ifconfig trunk0 trunkport re1 trunkport re2 trunkproto lacp

Seadme omaduste esitamiseks 

# ifconfig trunk0                 
trunk0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        lladdr 00:0c:42:07:1a:45
        priority: 0
        trunk: trunkproto lacp
        trunk id: [(8000,00:0c:42:07:1a:45,40E4,0000,0000),
                (8000,a8:b1:d4:95:a3:85,0003,0000,0000)]
               trunkport re2 active,collecting,distributing
               trunkport re1 active,collecting,distributing
        groups: trunk
        media: Ethernet autoselect
        status: active
        inet6 fe80::20c:42ff:fe07:1a45%trunk0 prefixlen 64 scopeid 0x1c
        inet 192.168.0.1 netmask 0xffffff00 broadcast 192.168.0.255

kus

  • trunk id järel on esitatud komponentide mac aadressid
  • tundub, et mõlema komponendi olemasolul reeglina ühendusega seotud väljuvad paketid liiguvad läbi ühe seadme ja sisenevad läbi teise

FreeBSD

vaja seadistada rc.confi 

ifconfig_em0="up"
ifconfig_em1="up"
cloned_interfaces="lagg0"
ifconfig_lagg0="laggproto lacp laggport em0 laggport em1"
ipv4_addrs_lagg0="192.168.1.3/24"

Ning ifconfig peaks seejärel teatama 

em0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=219b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,TSO4,WOL_MAGIC>
        ether 00:22:19:1d:7b:a8
        media: Ethernet autoselect (1000baseT <full-duplex>)
        status: active
em1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=389b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,WOL_UCAST,WOL_MCAST,WOL_MAGIC>
        ether 00:22:19:1d:7b:a8
        media: Ethernet autoselect (1000baseT <full-duplex>)
        status: active

lagg0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=209b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,WOL_MAGIC>
        ether 00:22:19:1d:7b:a8
        inet 192.168.1.3 netmask 0xfffffc00 broadcast 192.168.3.255
        media: Ethernet autoselect
        status: active
        laggproto lacp
        laggport: em1 flags=1c<ACTIVE,COLLECTING,DISTRIBUTING>
        laggport: em0 flags=1c<ACTIVE,COLLECTING,DISTRIBUTING>

Märkused

  • Tundub, et bondinguks ettevalmistatud switchi kaudu arvutit ei õnnestu üle PXE alglaadida.

Kasulikud lisamaterjalid

http://www.linuxfoundation.org/collaborate/workgroups/networking/bonding

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