Table of Contents Chapter 1 Link Aggregation Configuration

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1 Table of Contents Table of Contents Over LACP Link Aggregation Types Manual Aggregation and Static LACP Aggregation Dynamic LACP Aggregation Link Aggregation Load Sharing Types of Load Sharing Port States Link Aggregation Configuration Enabling/Disabling LACP on a Port Configuring the LACP Slow Period Timer Creating/Removing an Aggregation Group Adding/Removing an Ethernet Port to/from an Aggregation Group Enabling Aggregation Resource Extension Configuring Aggregation Group Description Configuring System Priority Configuring Port Priority Displaying and Maintaining Link Aggregation Link Aggregation Configuration Example i

2 1.1 Over When configuring link aggregation, go to these sections for information you are interested in: Over LACP Link Aggregation Types Link Aggregation Load Sharing Link Aggregation Configuration Displaying and Maintaining Link Aggregation Link Aggregation Configuration Example Link aggregation means aggregating several ports together into an aggregation group to implement load sharing among the member ports and to enhance the connection reliability. Link aggregation may be manual aggregation, dynamic LACP aggregation or static LACP aggregation. For the member ports in an aggregation group, their basic configurations are the same. That is, if one port in an aggregation group is a Trunk port, others must also be; when it turns into an Access port, then others must change to Access ports as well. Basic configuration includes STP, QoS, VLAN, and port attribute settings. The STP settings include the STP enabling/disabling status, link attribute (point-to-point or not), STP priority, path cost, max transmission speed, loop protection, root protection, and port type (whether the port is an edge port or not). The QoS settings include traffic limiting, priority marking, default 802.1p priority, bandwidth assurance, congestion avoidance, traffic redirection, and traffic statistics. VLAN settings include permitted VLAN types and default VLAN ID. The port attribute settings include port link type, such as trunk, hybrid, access, and detection group-related configuration. A device of the S9500 series can support up to 920 aggregation group IDs. IDs 1 though 31 indicate manual or static aggregation groups. IDs 32 through 192 are reserved. IDs 193 through 920 indicate dynamic aggregation groups, which are automatically generated by the system. The systems with MPLS VPN cards only support seven load balancing aggregation groups; those without MPLS VPN cards support 31 load balancing aggregation groups. The systems with FE boards using EX chips only supports seven load balancing aggregation groups. 1-1

3 Note: S9500 series also support inter-board aggregation. The inter-board aggregation is the same as the intra-board aggregation. 1.2 LACP Link Aggregation Control Protocol (LACP) based on the IEEE802.3ad standard can be used for dynamic link aggregation. An LACP-enabled port sends link aggregation control protocol data units (LACPDUs) to tell the peer about its system priority, system MAC address, port priority, port number and operation key. After receiving the information from the sender, the receiver compares it with the locally saved information about other ports, chooses member ports for the aggregation group and reaches agreement about whether a port can join or leave a dynamic aggregation group. During link aggregation, LACP generates a configuration mix according to the port configuration (rate, duplex, basic configuration, management key), which is called an operation key. The management key of an LACP-enabled dynamic aggregation port is 0 by default. The management key of an LACP-enabled static aggregation port is the same as the aggregation group ID. In a dynamic aggregation group, the member ports have the same operation key. In manual and static aggregation groups, the selected ports have the same operation key. 1.3 Link Aggregation Types The following three link aggregation types exist: manual aggregation, dynamic LACP aggregation, and static LACP aggregation Manual Aggregation and Static LACP Aggregation Both manual aggregation and static LACP aggregation are configured manually, and cannot be added or removed automatically. A manual or static LACP aggregation group must contain at least a member port. If only one port is contained, you can remove the port only by removing the aggregation group. Member ports in a manual aggregation are LACP-disabled while those in a static aggregation are LACP-enabled. You cannot change the LACP status on them. When a static aggregation group is removed, the member ports will form one or more dynamic LACP aggregation groups with LACP enabled. Ports in a manual/static aggregation group operating smoothly are in either selected state or standby state, although they may be in unselected state temporarily when the aggregation group is being established. Only the ports in selected state can transmit and receive data frames. Unselected state is an intermediate state which can be 1-2

4 ignored. In an aggregation group, the selected port with the least port number serves as the master port, while others as member ports. In a manual aggregation group, the ports that cannot be aggregated with the master port due to hardware limits (such as inter-board aggregation is unavailable) are in standby state. In a static aggregation group, the system sets the ports to selected or standby state based on these rules: Based on the descending order of priority levels from full duplex/high speed, full duplex/low speed, half duplex/high speed, to half duplex/low speed, the system sets the ports with the highest priority to selected state, and others to standby state. Set a port to standby state, if the port is connected to a device different from the one connected to the master port or the port does not belong to the aggregation group to which the master port belongs. The ports that cannot aggregate with the master port due to hardware restrictions (for example, cross-board aggregation restriction) are in standby state. The ports with their basic configurations different from the configuration of the master port are in standby state. An aggregation group can accommodate only a limited number of ports. If the number of selected ports in an aggregation group exceeds that allowed by the group, the ports with smaller port numbers are selected ports and others are standby ports. Both selected ports and standby ports can transmit and receive LACPDUs, but the standby ports cannot forward user service packets. Caution: On S9500 switches, you can aggregate ports with different rates. However, you are not recommended to use this function when S9500 switches are connected to the other devices Dynamic LACP Aggregation The system can create/delete dynamic LACP aggregations automatically, and you cannot add/delete member ports into/from a dynamic LACP aggregation. The system can aggregate a single port, which is called single port aggregation. On the members in a dynamic LACP aggregation, LACP is enabled. The system can only aggregate the ports with the same speed, duplex attribute, device connection, and basic configuration. 1-3

5 An aggregation group can accommodate a limited number of ports. If the number of the ports in an aggregation group exceeds that allowed by the group, the ports with smaller device ID (system priority + system MAC address) and smaller port ID (port priority + port number) are set as selected ports, and others as standby ports. If the maximum number is not exceeded, all the member ports are selected ports. Both selected and standby ports can transmit and receive LACPDUs, but standby ports cannot forward user service packets. In an aggregation group, the selected port with the least port number serves as the master port, while others as slave ports. When comparing device ID, the system compares system priority first, and then system MAC address in the case of the same system priority. The smaller device ID is regarded as higher priority. When comparing port ID, the system compares port priority first, and then port number in the case of the same port priority. The smaller port ID is regarded as higher priority. If the device ID changes to higher priority, the selected and standby state of the member ports in an aggregation group depends on the device port ID. You can also set system and port priority to define selected and standby ports. 1.4 Link Aggregation Load Sharing Types of Load Sharing A link aggregation group can be a load balancing aggregation group or a non-load balancing aggregation group. The S9500 series perform load sharing for IP packets (packets with the ETYPE field being 0800) based on destination and source IP addresses and for non-ip packets based on source and destination MAC addresses. As resources are limited, the system always allocates hardware aggregation resources to the load balancing aggregation groups with higher priority levels. When the load sharing aggregation resources are used up for existing aggregation groups, newly-created aggregation groups will be non-load sharing ones. The priority levels (in descending order) for allocating load sharing aggregation resources are as follows: Aggregation group containing special ports that need hardware aggregation resources, such as non-wire-speed 10GE ports. Aggregation group that probably reaches the maximum potential rate after the resources are allocated to it. If the aggregation groups will operate at the same rate after the resources are allocated to them, the one with the least master port number has a higher priority. Manual aggregation has a higher priority than static aggregation, and static aggregation has a higher priority level than dynamic aggregation. Under the same conditions, an aggregation group that has occupied resources has a higher priority than an aggregation group waiting for resources. When aggregation groups of higher priority levels appear, the aggregation groups of lower priority levels release their hardware resources. Single-port aggregation groups do not occupy hardware resources and can send and receive packets normally. 1-4

6 1.4.2 Port States In an aggregation group, ports can be in selected or standby state. Only the selected ports can transmit and receive user service packets. The selected port with the least port number serves as the master port, while others as member ports (also known as slave ports). Whether a port in an aggregation group is in selected or standby state is determined by the following rules. Based on the descending order of priority levels from full duplex/high speed, full duplex/low speed, half duplex/high speed, to half duplex/low speed, the system sets the ports with the highest priority to selected state, and others to standby state. The ports that cannot aggregate with the master port due to hardware limit are in standby state. The ports with their basic configurations different from the configuration of the master port are in standby state. An aggregation group can only accommodate a limited number of ports. If the number of selected ports in an aggregation group exceeds that allowed by the group, the ports with smaller port numbers are selected ports and others are standby ports. Selected ports can forward user packets, but the standby ports cannot. A load sharing aggregation group can contain multiple selected ports, but a non-load sharing aggregation group can have only one selected port, with other ports being standby ports. 1.5 Link Aggregation Configuration The following sections describe link aggregation tasks: Enabling/Disabling LACP on a Port Configuring the LACP Slow Period Timer Creating/Removing an Aggregation Group Adding/Removing an Ethernet Port to/from an Aggregation Group Enabling Aggregation Resource Extension Configuring Aggregation Group Description Configuring System Priority Configuring Port Priority 1-5

7 Note: When configuring a link aggregation group, the GVRP configuration on the master port is reserved, but GVRP will be disabled on the slave ports. After a port is added to a link aggregation group, GVRP on the port will be disabled. When the master port leaves its aggregation group, the status of GVRP feature on both the group and the port remains unchanged; when a slave port leaves its aggregation group, the GVRP feature on the port is disabled. The configuration of GVRP on any port in an aggregation group will be mapped to the master port of the group. When querying the GVRP feature configured on any port in an aggregation group, the returned result is about the master port of the group Enabling/Disabling LACP on a Port You should first enable LACP at the ports before performing dynamic aggregation, so that both parties can agree on adding/deleting the ports into/from a dynamic LACP aggregation group. Perform the following configuration to enable/disable LACP on a port: Enable LACP on a port lacp enable Available in Ethernet port Disable LACP on a port undo lacp enable Available in Ethernet port By default, LACP is not enabled on any port. Note that: You cannot enable LACP on mirroring ports, ports with a static MAC address, ports with static ARP, and ports with 802.1x enabled. You cannot enable LACP on the ports in a manual aggregation group. After a port with LACP disabled is added to a static LACP aggregation group, LACP will be enabled automatically on it. Note: The Smart Link function is mutually exclusive with LACP. That is, LACP cannot be enabled on a Smart Link group member port. 1-6

8 1.5.2 Configuring the LACP Slow Period Timer The slow period timer determines the interval for sending/receiving LACPDUs and the aging time when LACP negotiation is stable. You can set the timer to a smaller value for fast link switchover desired in a scenario similar to the following: Two LACP-enabled devices are connected through an intermediate transmit device and form an aggregate link group. In case a link connected to the intermediate device fails, traffic on the failed link will be switched to the other links in the link group after a period three times the slow period timer. To achieve faster switchover, you can decrease the slow period timer setting. Do not tune the LACP slow period timer otherwise. Follow these steps to tune the LACP slow period timer: Enter system system- Configure the LACP slow period timer Display LACP timer information lacp timer slow interval display lacp timer Required 30 seconds by default Available in any Caution: Two connected devices must be configured with the same LACP slow period timer setting. Otherwise, the aggregate link may be instable Creating/Removing an Aggregation Group You can create/remove a manual/static link aggregation group by performing the operations listed in the following table. After a link aggregation group is removed, all its member ports are disaggregated. Create a link aggregation group Remove a link aggregation group link-aggregation group agg-id mode { manual static } undo link-aggregation group agg-id Available in system Available in system 1-7

9 Caution: If the aggregation group that you are creating already exists but contains no member port, its type changes to the new one you set. When you change a static LACP aggregation group to a manual aggregation group, LACP are disabled on the member ports in the group automatically. Note: Link aggregation includes manual aggregation, static aggregation and dynamic aggregation. In the manual aggregation mode, ports working at different rates can be aggregated. Manual aggregation can be load balancing aggregation if aggregation resources are available. In this case, if the traffic on a low-rate port exceeds the maximum port rate, packets will be dropped. Do not configure aggregation groups if a system contains internal aggregation LPUs, which may conflict with the internal aggregation resources. Examples of such LPUs include RPRGE optical interface LPUs (LSB1RGP2GDB0 and LSB1RGP4GDB0), IPSec LPUs (LSB1IPSEC8DB0 and LSB2IPSEC8DB0), firewall LPUs (LSB1FW8DB0 and LSB2FW8DB0), and LSB1TGX1B0 LPUs. With aggregation resource extension disabled, the system allocates idle aggregation resources from 7 to 0; with aggregation resource extension enabled, the system allocates idle aggregation resources from 31 to 0. In the static aggregation mode, ports working at different rates can also be aggregated. However, the selected/standby state of statically aggregated ports is determined by the transmission rate. Only the ports with the maximum rate and in full-duplex mode can be selected to forward traffic Adding/Removing an Ethernet Port to/from an Aggregation Group Perform the following configuration to add/remove a port to/from an aggregation group: Add an Ethernet port to an aggregation group Remove an Ethernet port from an aggregation port port link-aggregation group agg-id undo port link-aggregation group Available in Ethernet port Available in Ethernet port 1-8

10 Aggregate Ethernet ports link-aggregation interface-type interface-number1 to interface-type interface-number2 [ both ] Available in system Caution: You cannot add mirrored ports, ports configured with a static MAC address, ports with 802.1x enabled, POS ports, or VPN ports to an aggregation group. If the aggregation group contains only one port, you cannot remove the port from the aggregation group unless you remove the aggregation group. After a port is added to an aggregation group, the original static ARP configuration of the port will be lost. Ports on XP4B LPUs and XP4CA LPUs cannot be added to an aggregation group. Internal ports on an OAP board cannot be aggregated with other ports Enabling Aggregation Resource Extension Follow these steps to enable aggregation resource extension: Enter system system- Enable aggregation resource extension link-aggregation extend Required Aggregation resource extension is disabled by default. By default, idle aggregation resources are allocated from 7 to 0 in the descending order for special port aggregation. With aggregation resource extension enabled, the system allocates idle aggregation resources from 31 to 0 in the descending order for special port aggregation. Special ports include RprGE ports and non-wire-speed 10GE ports. 1-9

11 Note: As for the aggregation resource extension function, note that: The function is unavailable to devices containing C-type LPUs. The function cannot be disabled when special port link aggregations are allocated the aggregation resources numbered from 7 to Configuring Aggregation Group Description Perform the following configuration to configure the description of a manual/static aggregation group: Set an aggregation group description Delete an aggregation group description link-aggregation group agg-id description alname undo link-aggregation group agg-id description Available in system Available in system By default, an aggregation group has no description. Caution: You cannot configure description for a dynamic aggregation group Configuring System Priority LACP uses system IDs in determining whether the member ports are selected or standby for a dynamic LACP aggregation group. The system ID consists of two-byte system priority and six-byte system MAC, that is, system ID equals system priority plus system MAC. In comparing system IDs, the system first compares system priority values; if they are equal, then it compares system MAC addresses. The member with the lower system MAC address wins out. Changing system priority may affect the priority levels of member ports, and then their selected or standby state. Perform the following configuration to configure the system priority: 1-10

12 Configure the system priority Restore the default system priority lacp system-priority system-priority-value undo lacp system-priority Available in system Available in system The default system priority is Configuring Port Priority LACP compares system IDs first and then port IDs (if the system IDs are the same) in determining if the member ports are selected or standby ones for a dynamic LACP aggregation group. If the number of ports in an aggregation group exceeds that allowed by the group, the ports with smaller port IDs are selected ports and others are standby ports. The port ID consists of two-byte port priority and two-byte port number, that is, port ID equals port priority plus port number. The system first compares port priority values and then port numbers and a smaller port ID is given priority. Perform the following configuration to configure the port priority: Configure the port priority Restore the default port priority lacp port-priority port-priority-value undo lacp port-priority Available Ethernet port Available Ethernet port The default port priority is Displaying and Maintaining Link Aggregation Display the summary of all aggregation groups Display detailed information of a specific or all aggregation groups Display the local device ID Display LACP timer information display link-aggregation summary display link-aggregation verbose [ agg-id ] display lacp system-id display lacp timer Available in any Available in any Available in any Available in any 1-11

13 Display detailed link aggregation information on specified port(s) Clear the LACP statistics for specified port(s) Enable LACP state debugging Enable LACP packet debugging Enable link aggregation error debugging Enable link aggregation event debugging display link-aggregation interface interface-type interface-number [ to interface-type interface-number ] reset lacp statistics [ interface interface-type interface-number [ to interface-type interface-number ] ] debugging lacp state [ interface interface-type interface-number [ to interface-type interface-number ] ] { { actor-churn mux partner-churn ptx rx }* all } debugging lacp packet [ interface interface-type interface-number [ to interface-type interface-number ] ] debugging link-aggregation error debugging link-aggregation event Available in any Available in user Available in user Available in user Available in user Available in user 1.7 Link Aggregation Configuration Example I. Configuration task Aggregate Ethernet 2/1/1 and Ethernet 2/1/2 in manual mode, static LACP aggregation mode, and dynamic LACP aggregation mode respectively to increase bandwidth between Switch A and Switch B and achieve LPU redundancy. II. Configuration prerequisites None III. Network diagram Figure 1-1 Network diagram for link aggregation configuration 1-12

14 IV. Configuration procedure The following only lists the configuration for switch A, and that on switch B is similar. 1) Manual aggregation # Create aggregation group 1. [Switch A] link-aggregation group 1 mode manual # Add Ethernet 2/1/1 and Ethernet 2/1/2 to aggregation group 1. [Switch A] interface ethernet 2/1/1 [Switch A-Ethernet2/1/1] port link-aggregation group 1 [Switch A-Ethernet2/1/1] interface ethernet 2/1/2 [Switch A-Ethernet2/1/2] port link-aggregation group 1 Note: When the numbers of the ports to be aggregated are consecutive, you can directly aggregate these ports into an aggregation group. The group number is allocated by the system automatically. For example, to aggregate Ethernet 2/1/1 and Ethernet 2/1/2 to form an aggregation group, you can use the following command: link-aggregation ethernet2/1/1 to ethernet2/1/2 both 2) Static LACP aggregation # Create aggregation group 1. [Switch A] link-aggregation group 1 mode static # Add Ethernet 2/1/1 and Ethernet 2/1/2 to aggregation group 1. [Switch A] interface ethernet 2/1/1 [Switch A-Ethernet2/1/1] port link-aggregation group 1 [Switch A-Ethernet2/1/1] interface ethernet 2/1/2 [Switch A-Ethernet2/1/2] port link-aggregation group 1 3) Dynamic LACP aggregation # Enable LACP on Ethernet 2/1/1 and Ethernet 2/1/2. [Switch A] interface ethernet 2/1/1 [Switch A-Ethernet2/1/1] lacp enable [Switch A-Ethernet2/1/1] interface ethernet 2/1/2 [Switch A-Ethernet2/1/2] lacp enable 1-13

15 Note: In the above example, the LACP-enabled ports must have the same basic configuration, rate and duplex mode to be in the same dynamic aggregation group; otherwise, they cannot aggregate successfully into a dynamic aggregation group to implement load sharing. 1-14