Configuring and Troubleshooting Eth-Trunks for S5700 Switches
Introduction
Ethernet link aggregation, also called Eth-Trunk, bundles multiple physical links into a logical link to increase link bandwidth, without having to upgrade hardware. Link aggregation increases bandwidth, improves link reliability, and enables load balancing.
This document discusses how to configure an Eth-Trunk in manual load balancing mode, how to configure an Eth-Trunk in LACP mode, and how to locate an Eth-Trunk fault.
Eth-Trunk Configuration
Link aggregation can work in manual mode or LACP mode. Before configuring an Eth-Trunk, perform step 1 and step 2.
- Check whether the interfaces between the two switches are connected through cables and are running properly.
Before connecting cables, run the display interface brief command to check interface status.
<HUAWEI> display interface brief PHY: Physical *down: administratively down ^down: standby ~down: LDT down #down: LBDT down (l): loopback (s): spoofing (E): E-Trunk down (b): BFD down (e): ETHOAM down (dl): DLDP down (d): Dampening Suppressed (ld): LDT block (lb): LBDT block (lp): Loop-detect block (ms): MACsec down (o): Observe-port forwarding down InUti/OutUti: input utility/output utility Interface PHY Protocol InUti OutUti inErrors outErrors GigabitEthernet1/0/0 down down 0% 0% 0 0 GigabitEthernet1/0/1 down down 0% 0% 0 0
After the cables are successfully connected, the interface status changes from Down to Up.
<HUAWEI> display interface brief PHY: Physical *down: administratively down ^down: standby ~down: LDT down #down: LBDT down (l): loopback (s): spoofing (E): E-Trunk down (b): BFD down (e): ETHOAM down (dl): DLDP down (d): Dampening Suppressed (ld): LDT block (lb): LBDT block (lp): Loop-detect block (ms): MACsec down (o): Observe-port forwarding down InUti/OutUti: input utility/output utility Interface PHY Protocol InUti OutUti inErrors outErrors GigabitEthernet1/0/0 up up 0.01% 0.01% 0 0 GigabitEthernet1/0/1 up up 0.01% 0.01% 0 0
- Check whether the interface configurations on both ends of an Eth-Trunk are consistent.
- Devices at both ends of the Eth-Trunk must use the same number of physical interfaces, duplex mode, and flow control mode.
- Devices at both ends of an Eth-Trunk must use the same link aggregation mode.
- In versions earlier than V200R011C10, only interfaces with the same rate can join an Eth-Trunk. For example, GE electrical interfaces and GE optical interfaces can be added to the same Eth-Trunk. In V200R011C10 and later versions, after the mixed-rate link enable command is run, interfaces with different rates can be added to the same Eth-Trunk.
When load balancing calculation is performed for an Eth-Trunk, the interface rate cannot be used as a weight. Therefore, when interfaces with different rates are added to an Eth-Trunk, the bandwidth of the Eth-Trunk is calculated based on the minimum interface rate. For example, if a GE interface and a 10GE interface are added to an Eth-Trunk, the GE interface rate is used for calculation. The actual bandwidth of the Eth-Trunk is 2 Gbit/s.
Configuring Link Aggregation in Manual Mode
Perform the following configurations:
<HUAWEI> system-view [HUAWEI] interface eth-trunk 1 //Create an Eth-Trunk. [HUAWEI-Eth-Trunk1] mode manual load-balance //Configure the Eth-Trunk to work in manual mode. [HUAWEI-Eth-Trunk1] quit [HUAWEI] interface gigabitethernet 1/0/0 //Add an interface to the Eth-Trunk. [HUAWEI-GigabitEthernet1/0/0] eth-trunk 1 [HUAWEI-GigabitEthernet1/0/0] quit [HUAWEI] interface gigabitethernet 1/0/1 //Add an interface to the Eth-Trunk. [HUAWEI-GigabitEthernet1/0/1] eth-trunk 1 [HUAWEI-GigabitEthernet1/0/1] quit
After the configuration is complete, run the display eth-trunk 1 command to check whether the Eth-Trunk is correctly configured. If the value of Operate status is up, the Eth-Trunk is working properly.
<HUAWEI> display eth-trunk 1 Eth-Trunk1's state information is: WorkingMode: NORMAL Hash arithmetic: According to SIP-XOR-DIP Least Active-linknumber: 1 Max Bandwidth-affected-linknumber: 8 Operate status: up Number Of Up Port In Trunk: 1 -------------------------------------------------------------------------------- PortName Status Weight GigabitEthernet1/0/0 Up 1 GigabitEthernet1/0/1 Up 1
Configuring Link Aggregation in LACP Mode
Perform the following configurations:
<HUAWEI> system-view [HUAWEI] interface eth-trunk 1 //Create an Eth-Trunk. [HUAWEI-Eth-Trunk1] mode lacp //Configure the Eth-Trunk to work in LACP mode. [HUAWEI-Eth-Trunk1] quit [HUAWEI] interface gigabitethernet 1/0/0 //Add an interface to the Eth-Trunk. [HUAWEI-GigabitEthernet1/0/0] eth-trunk 1 [HUAWEI-GigabitEthernet1/0/0] quit [HUAWEI] interface gigabitethernet 1/0/1 //Add an interface to the Eth-Trunk. [HUAWEI-GigabitEthernet1/0/1] eth-trunk 1 [HUAWEI-GigabitEthernet1/0/1] quit
After the configuration is complete, run the display eth-trunk 1 command to check whether the Eth-Trunk is correctly configured. If the value of Operate status is up, the Eth-Trunk is working properly.
<HUAWEI> display eth-trunk 1 Eth-Trunk1's state information is: Local: LAG ID: 1 WorkingMode: LACP Preempt Delay Time: Disabled Hash arithmetic: According to SIP-XOR-DIP System Priority: 32768 System ID: 0018-82d4-04c3 Least Active-linknumber: 1 Max Active-linknumber: 2 Operate status: up Number Of Up Port In Trunk: 2 -------------------------------------------------------------------------------- ActorPortName Status PortType PortPri PortNo PortKey PortState Weight GigabitEthernet1/0/0 Selected 1GE 10 262 2609 10111100 1 GigabitEthernet1/0/1 Selected 1GE 10 263 2609 10111100 1 Partner: -------------------------------------------------------------------------------- ActorPortName SysPri SystemID PortPri PortNo PortKey PortState GigabitEthernet1/0/0 32768 00e0-fc6e-bb11 32768 262 2609 10111100 GigabitEthernet1/0/1 32768 00e0-fc6e-bb11 32768 263 2609 10111100
Eth-Trunk in Manual Load Balancing Mode Cannot Go Up
Troubleshooting Flowchart
Run the display eth-trunk command to check the working mode of an Eth-Trunk. If WorkingMode is NORMAL, the Eth-Trunk is working in manual load balancing mode.
<Quidway> display eth-trunk 1 Eth-Trunk1's state information is: WorkingMode: NORMAL Hash arithmetic: According to SIP-XOR-DIP Least Active-linknumber: 3 Max Bandwidth-affected-linknumber: 8 Operate status: down Number Of Up Port In Trunk: 1 -------------------------------------------------------------------------------- PortName Status Weight GigabitEthernet1/0/0 Up 1 GigabitEthernet1/0/1 Down 1
Troubleshooting Procedure
- Check whether Eth-Trunk member interfaces are Up.
The physical status of Eth-Trunk member interfaces must be Up so that the Eth-Trunk can work properly.
Run the display eth-trunk command to check information about Eth-Trunk member interfaces. If the Eth-Trunk member interface goes Down, rectify the fault by referring to "Troubleshooting: Ethernet Interface Physically Down" in the Huawei S Series Switches Troubleshooting Guide.
- Check the configuration of the Eth-Trunk.
Run the display eth-trunk command to check whether the lower threshold for the number of active interfaces in the Eth-Trunk is configured. If the number of Eth-Trunk member interfaces in Up state is less than the lower threshold, the Eth-Trunk goes Down.
In the following command output, Least Active-linknumber indicates the lower threshold for the number of member links in Up state in an Eth-Trunk and is 3. However, the number of member interfaces in Up state in the Eth-Trunk is 1. Therefore, the value of Operate status is Down for the Eth-Trunk.
<Quidway> display eth-trunk 1 Eth-Trunk1's state information is: WorkingMode: NORMAL Hash arithmetic: According to SIP-XOR-DIP Least Active-linknumber: 3 Max Bandwidth-affected-linknumber: 8 Operate status: down Number Of Up Port In Trunk: 1 -------------------------------------------------------------------------------- PortName Status Weight GigabitEthernet1/0/0 Up 1 GigabitEthernet1/0/1 Down 1
By default, the lower threshold for the number of active interfaces is 1. You can run the least active-linknumber link-number command to configure the lower threshold.
- If the fault persists, collect information and contact Huawei technical support personnel.
Eth-Trunk Interface in LACP Mode Cannot Go Up
Troubleshooting Flowchart
Check the working mode of an Eth-Trunk using either of the following methods:
Method 1: Check the WorkingMode field in the display eth-trunk command output.
- If WorkingMode is NORMAL, the Eth-Trunk is working in manual load balancing mode.
- In V100R006C03, V100R006C05, and V200R001, if WorkingMode is STATIC, the Eth-Trunk is working in LACP mode.
- In V200R002 and later versions, if WorkingMode is LACP, the Eth-Trunk is working in LACP mode.
Method 2: Check the configuration in the Eth-Trunk interface view.
- In V100R006C03, V100R006C05, and V200R001, if mode lacp-static is configured, the Eth-Trunk is working in LACP mode.
- In V200R002 and later versions, if mode lacp is configured, the Eth-Trunk is working in LACP mode.
Troubleshooting Procedure
- Check whether Eth-Trunk member interfaces are Up.
The physical status of Eth-Trunk member interfaces must be Up so that the Eth-Trunk can work properly.
Run the display eth-trunk command to check information about Eth-Trunk member interfaces. If the Eth-Trunk member interface goes Down, rectify the fault by referring to "Troubleshooting: Ethernet Interface Physically Down" in the Huawei S Series Switches Troubleshooting Guide.
- Check the configuration of the Eth-Trunk.
Check whether the configuration on two ends of the Eth-Trunk is consistent. The LACP mode needs to be configured on both ends because LACP packet negotiation is involved.
Run the display eth-trunk command to check whether the lower and upper thresholds for the number of active interfaces in the Eth-Trunk are configured. If the number of Eth-Trunk member interfaces in Up state is less than the lower threshold, the Eth-Trunk goes Down.
<Quidway> display eth-trunk 1 Eth-Trunk1's state information is: Local: LAG ID: 1 WorkingMode: STATIC Preempt Delay: Disabled Hash arithmetic: According to SIP-XOR-DIP System Priority: 32768 System ID: 4cb1-6c3b-aaf5 Least Active-linknumber: 1 Max Active-linknumber: 8 Operate status: down Number Of Up Port In Trunk: 0 -------------------------------------------------------------------------------- ActorPortName Status PortType PortPri PortNo PortKey PortState Weight GigabitEthernet1/0/1 Unselect 1GE 32768 1 1329 10100010 1 GigabitEthernet1/0/2 Unselect 1GE 32768 2 1329 10100010 1 Partner: -------------------------------------------------------------------------------- ActorPortName SysPri SystemID PortPri PortNo PortKey PortState GigabitEthernet1/0/1 0 0000-0000-0000 0 0 0 10100011 GigabitEthernet1/0/2 0 0000-0000-0000 0 0 0 10100011
The default lower threshold for the number of active interfaces in an Eth-Trunk is 1. To configure the lower threshold, run the least active-linknumberlink-number command. The default upper threshold for the number of active interfaces in an Eth-Trunk is 8. To configure the upper threshold, run the max active-linknumberlink-number command.
If the least active-linknumber command has been configured before you run the max active-linknumberlink-number command, ensure that the upper threshold for the number of active interfaces is greater than or equal to the lower threshold for the number of active interfaces.
- Check whether Eth-Trunk member interfaces send and receive LACPDUs normally.
Run the display lacp statistics eth-trunk command to check statistics about LACPDUs sent and received by Eth-Trunk member interfaces.
<Quidway> display lacp statistics eth-trunk 1 Eth-Trunk1's PDU statistic is: ------------------------------------------------------------------------------ Port LacpRevPdu LacpSentPdu MarkerRevPdu MarkerSentPdu GigabitEthernet1/0/1 100 100 0 0
The number of increased packets is relevant to the timeout interval for an Eth-Trunk to receive packets. You can run the lacp timeout { fast | slow } command in the Eth-Trunk interface view to set the timeout interval for an Eth-Trunk in LACP mode to receive LACPDUs.
In fast mode, the remote end sends LACPDUs at an interval of 1 second. In slow mode, the remote end sends LACPDUs at an interval of 30 seconds. The fast mode ensures quicker response but consumes more system resources than the slow mode. The timeout intervals configured at the two ends can be different. You are advised to set the same LACPDU timeout interval on both ends to facilitate maintenance.
If the increase in the number of received LACPDUs is incorrect, check whether the remote end is not sending LACPDUs or the local end is discarding the received LACPDUs. If the number of LACPDUs received on the local end is incorrect, locate the reason the local interface does not receive LACPDUs.
For the S2700, S3700SI, S3700EI, S5700EI, S5700SI, and S5710LI, if the remote end sends LACPDUs but the local end does not receive the LACPDUs, check whether bpdu enable is configured on the Eth-Trunk. In V100R006 and later versions, bpdu enable is configured by default.
For the S9300, S9700, S7700, S12700, S7900, and other fixed switches, configure an ACL to obtain LACPDUs. If the remote end sends LACPDUs but the local end does not receive the LACPDUs, check whether the ACL has been delivered properly.
- In V100R002, run the display acl item resource slot slot-id apptype cpcar cpcar-name command in the hidden view to check whether the PHYEntryId field exists for LACP. If so, the ACL has been delivered.
In V100R003 and later versions, run the display bcmfpi resource slot 5 acl app-resource service-name cp-car cp-car-name command in the hidden view or diagnostic view to check whether the PHYEntryId field exists for LACP. If so, the ACL has been delivered.
- If the fault persists, collect information and contact Huawei technical support personnel.
Uneven Load Balancing of an Eth-Trunk
Troubleshooting Flowchart
Troubleshooting Procedure
- Check whether the packet characteristics match the load balancing mode.
Check whether characteristics of packets forwarded on an Eth-Trunk interface match the load balancing mode. If they do not match, for example, MAC addresses of forwarded packets are changed but the load balancing mode is src-ip, packets cannot be load balanced.
Perform the following operations:- Check the packet characteristics.
- Packet forwarding mode: Known and unknown unicast packets are forwarded through different processes and use different default load balancing algorithms. You need to first check whether packets are known unicast packets or unknown unicast packets.
- Variable field of packets: Determine whether the MAC address, IP address, or label of the packet changes.
- Packet type: Determine whether the packet is an IP packet, an MPLS packet, or a Layer 2 packet.
NOTE:
If the destination MAC address of a packet does not exist in the MAC address table, the packet is an unknown unicast packet.
- Check the load balancing mode of the Eth-Trunk interface.
Check the Eth-Trunk load balancing mode based on the packet forwarding mode (known unicast packets or unknown unicast packets).
- Check the load balancing mode for known unicast packets.
For known unicast packets, run the display eth-trunk command to check the load balancing mode in the Hash arithmetic field. Alternatively, you can check the Eth-Trunk configuration to confirm the load balancing mode.
<HUAWEI> display eth-trunk 1 display eth-trunk 1 Eth-Trunk1's state information is: WorkingMode: NORMAL Hash arithmetic: According to SIP-XOR-DIP Least Active-linknumber: 1 Max Bandwidth-affected-linknumber: 8 Operate status: down Number Of Up Port In Trunk: 0 ------------------------------------------------------------------ PortName Status Weight ......
NOTE:
The load balancing parameters are described as follows:
SIP indicates the source IP address; DIP indicates the destination IP address; SA indicates the source MAC address; DA indicates the destination MAC address.
SIP-XOR-DIP indicates that the outbound interface is selected based on the exclusive OR operation between the source IP address and destination IP address.
SA-XOR-DA indicates that the outbound interface is selected based on the exclusive OR operation between the source MAC address and destination MAC address.
ENHANCED indicates that a load balancing profile is applied and the outbound interface is selected based on the load balancing mode specified in the profile.
If the load balancing mode is ENHANCED, check the load balancing mode in the enhanced profile.
There is only one global load balancing profile. This profile takes effect for both known and unknown unicast packets, and uses different fields for calculation based on the packet type.
You can run the display load-balance-profile command to display detailed information about a specified load balancing profile. HashField indicates the configured load balancing mode.
<HUAWEI> display load-balance-profile Load-balance-profile: test //test indicates the enhanced profile name. Packet HashField - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - IPV4 sip dip IPV6 sip dip L2 smac dmac MPLS top-label 2nd-label
- Check the load balancing mode for unknown unicast packets using the display current-configuration | include unknown-unicast load-balance command. By default, unknown unicast traffic is load balanced based on source and destination MAC addresses of packets.
<HUAWEI> display current-configuration | include unknown-unicast load-balance unknown-unicast load-balance dmac
- Check the load balancing mode for known unicast packets.
- Check whether the packet characteristics match the load balancing mode.
If packet characteristics do not match the load balancing mode, change the load balancing mode based on the traffic model of the live network. When the load balancing mode based on the variable parameter is used, traffic is evenly load balanced.
For example, one PC is used for testing, and the source IP address and source MAC address of packets remain unchanged but the destination IP address and destination MAC address change. If the load balancing mode is based on the source IP address or source MAC address, traffic cannot be load balanced. In this case, load balancing must be based on the destination IP address or destination MAC address.
If packets are known unicast packets, run the following commands:
<HUAWEI> system-view [HUAWEI] interface Eth-Trunk 1 [HUAWEI-Eth-Trunk1] load-balance dst-mac [HUAWEI-Eth-Trunk1] quit
If packets are unknown unicast packets, run the following commands:
<HUAWEI> system-view [HUAWEI] unknown-unicast load-balance dmac
If the enhanced load balancing mode is used, change the load balancing mode of the corresponding packet type (such as IPv4, IPv6, MPLS, and Layer 2) in the enhanced profile.
For example, to change the load balancing mode of IPv4 packets to dip in the enhanced profile test, run the following commands:
<HUAWEI> system-view [HUAWEI] load-balance-profile test [HUAWEI-load-balance-profile-test] ipv4 field dip [HUAWEI-load-balance-profile-test] quit
- Check the packet characteristics.
- Check whether the number of selected member interfaces is an exponential multiple of 2.
If the number of selected member interfaces is an exponential multiple of 2, more even load balancing can be achieved.
Run the display eth-trunk command to check the selected member interfaces:
- In LACP mode (WorkingMode is STATIC in V100R006C03, V100R006C05, and V200R001, and is LACP in V200R002 and later versions), the value of Status is Selected for a selected member interface.
- In manual mode (WorkingMode is NORMAL), the value of Status is Up for a selected member interface.
<HUAWEI> display eth-trunk 1 Eth-Trunk1's state information is: Local: LAG ID: 1 WorkingMode: LACP Preempt Delay Time: 10 Hash arithmetic: According to SIP-XOR-DIP System Priority: 120 System ID: 0018-82d4-04c3 Least Active-linknumber: 1 Max Active-linknumber: 2 Operate status: up Number Of Up Port In Trunk: 2 -------------------------------------------------------------------------------- ActorPortName Status PortType PortPri PortNo PortKey PortState Weight GigabitEthernet1/0/2 Selected 1GE 10 262 2609 10111100 1 GigabitEthernet1/0/3 Selected 1GE 10 263 2609 10111100 1 GigabitEthernet1/0/4 Unselect 1GE 32768 264 2609 10100000 1 Partner: -------------------------------------------------------------------------------- ActorPortName SysPri SystemID PortPri PortNo PortKey PortState GigabitEthernet1/0/2 32768 00e0-fc6e-bb11 32768 262 2609 10111100 GigabitEthernet1/0/3 32768 00e0-fc6e-bb11 32768 263 2609 10111100 GigabitEthernet1/0/4 32768 00e0-fc6e-bb11 32768 264 2609 10110000
- Check whether member interfaces of an Eth-Trunk reside on different chassis in a stack or CSS.
This step does not need to be performed for unknown unicast packets.
By default, local preferential forwarding is enabled on an Eth-Trunk interface. In a stack or CSS, if the outbound interface of packets received on a stack or CSS member interface is an Eth-Trunk, the packets are forwarded through a functioning Eth-Trunk member interface on the chassis, but not an Eth-Trunk member interface on another stack or CSS member chassis.
In this case, you can run the following commands to disable the local preferential forwarding function:
<HUAWEI> system-view [HUAWEI] interface Eth-Trunk 1 [HUAWEI-Eth-Trunk1] undo local-preference enable [HUAWEI-Eth-Trunk1] quit
NOTE:
This function is valid only for known unicast packets, and does not work with unknown unicast packets, broadcast packets, and multicast packets.
- If the fault persists, collect information and contact Huawei technical support personnel.
