At8000 s configurando trunking

Link Aggregation

AT-8000S

Trunk/SmartTrunk/port-channel

• Several physical ports are joined together to be one logical port with a higher bandwidth.

• Link aggregation is defined and controlled by the IEEE802.3ad standard.

Device #1 Device #2Channel

Link Aggregation

• Providing higher bandwidth connections where and when needed, without requiring higher bandwidth connections.

• Better bandwidth granularity – if a connection needs to have a higher capacity than the standard link, it can be achieved without requiring a link with a 10-fold speed increase, which may well be an overkill (or may not exist) .

• The trunk has many terms: Trunks, Aggregated Links, Link Aggregation Groups - LAG, Channel-group and Port-channeling

• Aggregated Links may be set up manually, or automatically by enabling LACP (Link Aggregation Control Protocol) on the relevant links.

• An Aggregated Link is treated by the system as a single logical port, in the same manner as any other port in the system.

• In particular, the Aggregated link has port attributes similar to a “regular” port – Auto negotiation state, speed, Duplex setting, etc.

• These attributes are applied to all ports in the LAG• The system uses balancing rules to decide which frames will be

forwarded on which aggregate-link member.

LAG – Types and Attributes

Link Aggregation ports

• The user may aggregate ports into link-aggregation port-groups. Each group is composed of ports of the same speed.

• Ports in a LAG may be of different media types (Copper/Fiber, or different fiber types), provided they have the same speed capabilities.

Aggregated Link Port Type

• Each Aggregated Link has an “Aggregated Link Port Type” (e.g. Fast Ethernet, Gigabit Ethernet). This is defined as the type of the first port to be added to this Aggregated link.

• A port may be added to an aggregated link only if it has the same type as the “Aggregated Link Port Type”

• When a port is added to a LAG, it takes on the attributes of the aggregated link.

Applications

LAG

LAG

Multimedia Server

WEB server

FTP Server

FTP Server

WEB ServerWindows

WEB ServerLinux

AT-8000SLAG

Implementation

LAG on the AT-8000S

• The AT-8000S supports 8 Aggregated Links each with up to 8 member ports.

• The LAGs already exist on the device, and do not have to be created. All that is needed is to add the ports to the existing aggregate links.

• Features includes: – aggregate throughput– incremental bandwidth– link redundancy– traffic load balancing

LAG Configuration Rules

• If a VLAN is configured on a port it cannot be added to a LAG (excluding the default VLAN VID#1)

• When a port is added to a LAG – it is removed from the default VLAN

• All the ports who are members of a LAG automatically implement the auto negotiation and speed configuration of the LAG.

LAG Configuration Rules

• By default auto negotiation is enabled on the LAG, but user can define it to full duplex and set speed.– Ports may be configured for speed and auto negotiation when

they are members of a LAG, but the setting will not take effect until they are removed from the LAG. That way the user may set the port settings for the port to be implemented when/if it is removed from the LAG.

LAG –Load Balance

• The Packet Processor performs load balancing for packets to be transmitted on the LAG.

• Load balancing is performed for all types of packets transmitted on the LAG (Unicast; multicast, broadcast and unknown).

• The hash index is calculated so as to load-balance the traffic evenly across all LAG members, at the same time ensuring that packets of any given flow are not reordered.

LAG – User Setting

• Port level settings:– Adding/removing from a channel group– Defining the LAG member as static (on) or LACP (auto).

• Channel- port level settings:– General port settings (e.g flow-control, back-pressure, auto-

negotiation, GVRP, STP, port speed etc), like any other port interface.– Note that LAG can be either auto-negotiation or full duplex but not half

duplex

AT-8000SLAG

CLI Configuration

CLI – Adding Ports to LAGs

• Use the following Interface Mode command to add a port to a Channel-Port:

channel-group port-channel-number mode {on|auto}

• Mode “on” is static LAG and mode “auto” is LACP

• Note that the port cannot belong to a VLAN other than the default VLAN.

• Use the “no” form of the command to remove the channel group configurationno channel-group

CLI – LAG Configuration

• Example – LAG (Static) configuration:– Adding port range 1/e1- 7 to channel-group 1

console# configure

console(config)# interface Range ethernet 1/e(1-7)

console(config-if)# channel-group 1 mode on

12-Aug-2004 17:44:57 %TRUNK-I-PORTADDED: Port 1/e1 added to ch1

12-Aug-2004 17:44:57 %LINK-I-Up: ch1







console(config-if)# 12-Aug-2004 17:45:27 %STP-W-PORTSTATUS: ch1: STP status Forwarding

CLI –LAG Show Commands

• Use the following EXEC Mode command to view the members of a group-channel

show interfaces port-channel [port-channel-number]• To view all port-channels – omit the channel number.

CLI – LAG Show Command

• Example – showing information for port-channel 1– Ports who are members in the port-channel

console# show interfaces port-channel 1

Channel Ports

....... .....

ch1 active: 1/e(1-7)

AT-8000S

LACP

LACP - General

• Link Aggregation Control Protocol (LACP)• The 802.3ad standard provides for the formation of a single Layer 2

link from two or more standard Ethernet member links via automatic member link activation

• LACP provides a robust means of assuring that both ends of the link are up and agree to be members of the aggregation before the link member is activated

• LACP must be enabled at both ends of the link to be operational.• It automatically determines which member links can be aggregated

and then aggregates them. It provides for the controlled addition and removal of physical links to the link aggregation such that no frames are lost or duplicated

LACP Operation

• LACP has no concept of “request and response” – the protocol does not issue any “commands”

• LACP expects all devices to “make the right decision” based on their own state and protocol distributed information

• Devices compare their own information with that of their neighbors and decide what action to take

• Information exchange is periodic and timely – so any change in configuration is detected

• LACP messages are contained within the specific link

LACP Process – device ID

• Messages are sent between 2 attached devices• Each device sees itself as the “actor”, and the other device as

the “partner”• The “Actor” (i.e each device) compares its own information to

that of the partner and decides what actions to take• LAGs are created only among links connecting the same pair

of devices• Therefore, each device has a unique system ID. As in STP it

is 64 bits long containing a priority field (16 bits) + MAC (48 bits)

SysID=pr_field+MAC• An Actor will consider aggregating links together only if the

parallel links on the other (Partner) device have the same system ID, as indicated in their LACP information

LACP Process – System Key

• Another use for the system ID is to determine which device has the lower ID (can be controlled by the priority field)

• For links to aggregate to one LAG – not only must they have the same system ID, they also have to have the same system allocated (LAG) key (16 bits).

• Links with the same device ID but different key values – cannot be aggregated to the same LAG

LACP Process – System Key

• Keys are assigned by the system and can be based on:

– Different speeds– Physical limitation (of device) to aggregate ports– User defined groups (i.e defined as a separate LAG group by

administrator)

Summary: for links to be join together in a LAG with another device, they must have the following 3 identical values: System priority System MAC System allocated (LAG) key

LACP Process – Port Priority

• Each potential aggregate port has a port ID consisted of a port priority (16 bits) and port number (16 bits)

• A Lower ID means a higher priority• The port ID determines which ports will have

precedence over others to join the LAG• The system with the LOWER SYSTEM ID is the one

who “rules” on port priority, and therefore which links have precedence in joining a LAG (if there are more links than LAG allows)

LACP Process – sending messages

• LACP ports have 2 modes of operation:– Active mode – will generate LACP messages on a regular

basis – Passive mode – will not generates messages unless first

“spoken to” (by an active mode port)• Messages can be sent in a fast rate (1 sec’) or slow rate

(30 sec’). The rate used is determined by the partner.• Each message contains information of both Actor and

identified Partner

Device #2

• System priority – 16bits• MAC – device MAC address• Key – Key number of the dynamic LAG. (ifindex of the LAG)

• *Port-priority• *Port number

LACP PDU (Actor and Partner)

Device #1

LAG ID

Will be used only when ports exceed the number of allowed ports within the LAG

Actor/Partner state in the PDU

• ‘0’ – Activity 1=active mode; 0= passive mode• ‘1’ – Time out 0=long 30 sec’; 1=short 1sec’• ‘2’ – Aggregation 0=individual only; 1=can be aggregated• ‘3’ – Synchronize 0=admin; 1=operative active state• ‘4’ – Collecting 0=off; 1=on• ‘5’ – Distribute 0=off; 1=on• ‘6’ – Default• ‘7’ – Experience

0 1 0 0 0 1 1 07 6 5 4 3 2 1 0

0x46

AT-8000SLACP

Implementation

LACP – Implementation

• Layer 2 protocol• LACP must be enabled at both ends of the link to be

operational• Static and dynamic ports can not work at the same LAG• Ports are in the Active mode.• Each LAG has its own specific LAG key, which is the

“ifIndex” of the LAG interface.• User can configure more than 8 ports as potential LACP

LAG members. However LACP will use only up to 8 ports with “best” (lowest) port ID.

LACP – Implementation

• If several ports with different operative speed (due to auto-negotiation…) are attempting to join a new or existing LAG, only the higher speed port(s) will join, and lower speed ports will not join/ will be removed from the LAG

• The system will notify the user (log message, SNMP trap, etc.) whenever a port is added/removed from an Aggregated Link, or when it changes state to/from standby, or changes its attributes due to auto negotiation.

LAG ID and Port Priority

• When LACP is used, each LAG is uniquely identified by a LAG ID.

• The value of the LAG ID is important to BOTH SIDES OF THE LAG.

• All ports in a LAG (on a single device) must have the same LAG ID.

• Ports have a per-port LAG priority. When an “Opening” for an additional LAG member is available, and there are inactive LAG members, they will be made Active in the order of their port LAG priority.

LAG - Port Priority

• If the per-port LACP priority of the link is lower than that of the currently active link members, and there is already the maximum possible number of active members, then the link will be made inactive.

• If the per-port LACP priority of the new link is higherthan that of one the currently active link members, the new link will become active, and an existing link will be made inactive.

Device #1

Device #3

Device #2

Key 25

100FE100FE100FE10FE10FE10FE

100FE100FE100FE10FE10FE10FE

Key 26

Key 27

Key 28

Key 29

Example 1

E1 E2 E3 E4 E5 E6

E1E2E3E4E5 E6

Device #1

Device #3

Device #2

Key 25

Key 26

Key 27

Key 28

10FE10FE10FE

10FE10FE10FE

Key 29

100FE 100FE

Example 2

100FE

100FE

100FE100FE100FE

100FEE1 E2 E3 E4 E5 E6

E1E2E3E4E5 E6

Device #1

Device #3

Device #2

Key 25

Key 26

Key 27

Key 28

10FE10FE100FE

10FE10FE

100FE

Key 29

Example 3

E1 E2 E3 E4 E5 E6

E1E2E3E4E5 E6

100FE

100FE

100FE100FE100FE

100FE

LACP – User Setting

• Device Level Configuration:– Assign system priority (1-65535; default is 1)

• Port-Channel Level configuration:– The same as in regular LAG

• Port Level configuration:– Adding a port to a LAG and defining it as LACP– Assign port priority (1-65535; default is 1)– Define short or long timeout (default is short)

AT-8000SLACP

CLI Configuration

CLI – Adding Ports to LACP LAGs

• Use the following Ethernet Interface Mode command to add a port to a LACP Channel-Port:

channel-group port-channel-number mode auto• Mode “auto” is LACP type channel• Note that the port cannot belong to a VLAN other than the

default VLAN.• Use the “no” form of the command to remove the channel

group configurationno channel-group

CLI – LACP System Priority

• Use the following Global Mode command to set LACP system priority (the “no” form resets value to default):

lacp system-priority valueno lacp system-priority

CLI – LACP port Parameters

• Use the following Ethernet Interface Mode command to set LACP port priority (the “no” form resets value to default):

lacp port-priority valueno lacp port-priority

• Use the following command to set LACP port timeout value (the “no” form resets value to default):

lacp timeout { long | short }no lacp timeout

CLI – LACP Configuration

• Example –LACP configuration:– Adding port range 1/e11-18 to channel-group 3– Defining system priority to 100– Defining LACP port priority of port 1/e10 to 50– Defining timeout of port 1/e10 to long

console(config)# interface Range ethernet 1/e(11-18)

console(config-if)# channel-group 3 mode auto

console(config-if)#

console(config)# lacp system-priority 100

console(config)# interface ethernet 1/e10

console(config-if)# lacp port-priority 50

console(config-if)# lacp timeout long

CLI – LACP Show Commands

• To view LACP parameters of a specific Ethernet port (omit keyword to view all details):

show lacp ethernet interface [parameters | statistics | protocol-state]• The can be displayed:

– Parameters: Actor and Partner parameters– Statistics – PDU sent and received– Protocol state: protocol state info

• If the port is not LACP, show command will state only that the port is not LACP enabled.


• Example –LACP command, show:– port 1/e4 (doesn’t belong to LACP LAG)– statistic for port 1/e11 (LACP LAG port)

console# show lacp ethernet 1/e4 parameters

LACP is not enabled on 1/e4

console# show lacp ethernet 1/e11 statistics

1/e5 LACP statistics:

LACP Pdus sent: 30

LACP Pdus received: 0


• Example – show port 1/e6 LACP parameters:

console# show lacp ethernet 1/e6 parameters

1/e11 LACP parameters:

Actor

system priority: 1

system mac addr: 00:00:b0:11:22:99

port Admin key: 1004

port Oper key: 1004

port Oper number: 6

port Admin priority: 1

…..

…..

CLI – LACP Show Commands• To view LACP parameters of a port channel:show lacp port-channel [ port_channel_number ]

console# show lacp port-channel 1Port Type 100 EthernetAttached Lag id:Actor

System Priority:100MAC Address: 20:06:12:03:10:00Admin Key: 1000Oper Key: 1000

PartnerSystem Priority:0MAC Address: 00:00:00:00:00:00Oper Key: 0

AT-8000SLag and LACP

Examples

Example #1

AT-8000S #1 AT-8000S #2 AT-8000S #3

Regular LAG

LACP LAG

Vlan 33 (Access)

CoS 7

Vlan 33, 34, 35 (trunk)

GVRP enable (on

LAG)

Example 1 - Configuration

• Configuration relates to AT-8000S #2• Define ports 1/e(1-7) as Channel-Group 1, - regular LAG• Define ports 1/e(16-23) as channel-group 2 - LACP LAG• Before adding ports use show command to verify that

ports do not have configuration which does not allow them to join a LAG (such as VLAN, GVRP, IP address, ACL etc)

Example 1 - Configuration

• On channel group 1 – define it as a VLAN trunk mode port, with VLANs 33,34,35. Enable GVRP on the LAG.

• On channel group 2 – define it as Access VLAN port member of VLAN 33. Assign the LAG default COS of 7.

Example 1 - Table

LAG VLAN Other

1/e1-7 LAG 1 mode on No VLAN on ports

“Clean port”

1/e16-23 LAG 2 mode auto

No VLAN on ports

“Clean port”

LAG 1 ----- Trunk VID 33,34,35

GVRP enable

LAG 2 ----- Access VID 33 Default COS = 7

InterfaceConfig

Example 1 - CLI

console(config)#

console# configure

console(config)# vlan database

console(config-vlan)# vlan 33-35

console(config-vlan)#

console(config)# interface range ethernet 1/e(1-7)


L3 interface is defined on port 1/e1

console(config-if)#

console(config)# interface ethernet 1/e1

console(config-if)# no ip address

console(config)# interface range ethernet 1/e1-7


console(config-if)#

Example 1 – CLI Cont’

console(config)# interface range ethernet 1/e(16-23)

console(config-if)# channel-group 2 mode auto

console(config-if)#

console(config)# interface port-channel 1

console(config-if)# switchport mode trunk

console(config-if)# switchport trunk allowed vlan add 33-35

console(config-if)# gvrp enable

console(config-if)#

console(config)# interface port-channel 2

console(config-if)# switchport access vlan 33

console(config-if)# qos cos 7

console(config-if)#


console# show vlan

Vlan Name Ports Type

---- -------------------------------- --------------------------- ------------

1 1 1/e(8-15, 24), ch(1,3-8) other

33 33 ch(1-2) permanent

34 34 ch1 permanent

35 35 ch1 permanent

console# show interfaces port-channel

Channel Ports

....... .....

ch1 Active: 1/e(1-7)

ch2 Active: 1/e(16-23)

….

ch8


console# show lacp port-channel 2

Port-Channel ch2

Port Type 100 Ethernet

Attached Lag id:

Actor

System Priority:1

MAC Address: 20:06:12:03:10:00

Admin Key: 1001

Oper Key: 1001

Partner

System Priority:0

MAC Address: 00:00:00:00:00:00

Oper Key: 0

consconsole#

AT-8000SLAG & LACP

Troubleshooting

Troubleshooting

The challenges for LAG can be divided into two main areas: • Troubleshooting during the configuration phase, and

troubleshooting during the execution phase. • Configuration errors usually occur because of mismatched

parameters on the ports involved (different speeds, different duplex, and so on).

• But you can also generate errors during the configuration by setting the channel on one side to “on” and waiting too long before configuring the channel on the other side. This causes spanning tree loops, which generate an error in the network.

Troubleshooting

• Link aggregation and Spanning-Tree protocol.– The port will be automatically configured to the LAG

parameters whenever joining the group. When the port is removed from the group, the port will return to its own “private” port configuration.

– Configuring two devices for LAG while already connected. (disable ports, configuring, enable ports).

• Link aggregation and tagging.– These are completely separate features. The same as

previous item: The port will be automatically configured to the LAG parameters whenever joining the group.

Possible problem

Problem description

Solution

There is no traffic through the LAG

Ping doesn’t run between devices through the LAG

1. Use show interfaces port-channel command to check that the configuration of the particular LAG is correct.

2. Use show lacp ethernet command to check whether lacp is enabled on the particular port.

3. Use show lacp port-channel command to check LAG attributes.

4. Use show interfaces configuration command to check that the ports to be grouped have the same settings

5. Use show spanning-tree port-channel command to check the LAG spanning-tree parameters

Possible problem Problem description

Solution

Traffic is not forwarded on some of the LAG ports

Some ports where added to a LAG as members, but when running traffic on the device they are not used to forward packets

1. If LAG is configured to auto-negotiation some of its links may have reduced speed to 100/10Mbps. In such a case lower speed ports will not be active in the LAG. Use show interfaces status to view LAG ports speed.

2. If LAG is LACP, there may be more ports defined to the LAG then actually operationally possible (on this or neighbor device). Beyond the allowed number, ports with lower port priority will be set to inactive. Use show lacp ethernet X parameters to view specific port priority. Use lacp port-priority command to set port priority.

3. If LACP LAG port is connected to a regular port on neighbor device – it will not function as a LAG member.

4. Due to physical problems port has synchronization problems and will not function properly. Disconnect and reconnect port

Possible problem Problem description

Solution

There are no trap messages neither on the ASCII terminal nor on the SysLog server regarding dynamic port joining the LAG

Ping doesn’t run between devices through the LAG

1. Check that the device security parameters are configured correctly.

2. Check configuration of the SysLog Server3. If needed perform set of operations presented on the

previous slide.

Business

At8000 s configurando trunking