Discard frames appear for outbound direction because of burst traffic

Issue Description

Few months ago, a customer was using 100M ethernet uplink line to connect access Huawei switch 2700 with distribution Huawei switch S5700. In order to increase the uplink bandwidth, he changed from 100Mbps line to 1 Gbps line.
Unfortunately this adjustment was not a good one, because immediately after change, the interfaces that were connecting access users, started to increment discards for outbound direction.
I will skip any introduction, and i will share the topology.
QQ图片20170720105414

Alarm Information

Discards packets appear on outbound.
Ethernet0/0/1 current state : UP
Line protocol current state : UP
Description:host1
Switch Port, PVID : 1105, TPID : 8100(Hex), The Maximum Frame Length is 1536
IP Sending Frames’ Format is PKTFMT_ETHNT_2, Hardware address is d4b1-10cd-870f
Port Mode: COMMON COPPER
Speed :  100,  Loopback: NONE
Duplex: FULL,  Negotiation: ENABLE
Mdi   : AUTO
Last 60 seconds input rate 103712 bits/sec, 80 packets/sec
Last 60 seconds output rate 1760720 bits/sec, 175 packets/sec
Input peak rate 163903392 bits/sec, Record time: 2014-05-20 04:26:04
Output peak rate 274790504 bits/sec, Record time: 2014-05-20 04:43:57
Input:  7852997 packets, 1499049380 bytes
Unicast        :             7852997, Multicast          :                   0
Broadcast      :                   0, Jumbo              :                   0
CRC            :                   0, Giants             :                   0
Jabbers        :                   0, Fragments          :                   0
Runts          :                   0, DropEvents         :                   0
Alignments     :                   0, Symbols            :                   0
Ignoreds       :                   0, Frames             :                   0
Discard        :                   0, Total Error        :                   0
Output:  12833895 packets, 16448124820 bytes
Unicast        :            12815530, Multicast          :               18363
Broadcast      :                   2, Jumbo              :                   0
Collisions     :                   0, Deferreds          :                   0
Late Collisions:                   0, ExcessiveCollisions:                   0
Buffers Purged :                   0
Discard        :               12035, Total Error        :                   0
Input bandwidth utilization threshold : 100.00%
Output bandwidth utilization threshold: 100.00%
Input bandwidth utilization  : 0.10%
Output bandwidth utilization : 1.76%

Please check below the NMS graph for discard packets.

QQ图片20170720105534

Handling Process

1. Enable the burst traffic mode to improve the capability of the device for carrying the burst traffic.
<Quidway> system-view
[Quidway] burst-mode enable
By default, to ensure that each interface uses buffer resources of the system fairly, the buffer resources of the system are evenly allocated to the interfaces. In this case, the packet loss threshold is low. If the network traffic is even and stable, you can use the configuration. If the burst traffic is heavy on the network, packets are lost easily. After the burst traffic mode is enabled, if the burst traffic occurs on a single interface, other interfaces can use idle buffer resources of the system. The capability of the device for carrying burst traffic is improved.

Well this is a cool command because the situation was improved, let’s check the graph now:

QQ图片20170720105840

We can see that after 18th of June, discards are insignificant.

2. We almost solve it. But how to make discards disappear once and for all?
Below picture speaks for itself.

QQ图片20170720110017

We can do shaping on upstream device. Shaping will send packets towards S2700 at even speed rate, so actually the burst traffic will be buffered at S5700 level and eliminated completely on S2700 level.

I hope you enjoy reading this case.

Root Cause

Actually, even if you don’t believe me, this graph made me understand what really happens.
1. discards appear immediately after change 10 June (uplink swap)
2. the event incidence is not periodical.
3. the quantity is never the same.
This 3 points made me think we are facing a problem with burst traffic handling. Obviously a 1Gbps interface will be able to receive a higher amount of burst traffic, while mixed incidence and quantity are conditions for burst traffic type.
Because now we know the root-cause, how to solve this?

Suggestions

none.

 

dot1x authentication fails on S5700

Issue Description

Authentication fails on Huawei S5700 for all users. Error received but host is : Unable to connect.

Alarm Information

none

Handling Process

As a solution for this issue you need to change the port dot1q confguration. A port configured for only one user is an access port and this configuration needs to be changed to hybrid mode so it can support more than one users. You can find the initial configuration and the modified version below:

before:
port link-type access
port default vlan 105
dot1x enable
dot1x max-user 1
authentication guest-vlan 101
authentication restrict-vlan 104
dot1x port-method port
dot1x reauthenticate

after (working config):
port hybrid pvid vlan 105
port hybrid untagged vlan 2 to 4094
dot1x enable
dot1x max-user 2
authentication guest-vlan 101
authentication restrict-vlan 104
authentication critical-vlan 105

Root Cause

This failure is caused by the fact that more than one user needs to authenticate on a port configured to support only one user.

Suggestions

if you need to use port-method mac always configure the port in hybrid mode.

Contact information:

Telephone: 852-30623083
Email: Sales@Thunder-link.com
Supports@Thunder-link.com
Website: http://www.thunder-link.com

 

How Do I Obtain the Serial Number of a Modular Switch

Issue Description

How Do I Obtain the Serial Number of a Modular Switch?

Solution

Obtaining the Chassis Serial Number

  • In a standalone switch:

Log in to the switch through Telnet or the console interface, and then run the display elabel backplane command in the user view to display the electronic label information. The BarCode field in the command output shows the chassis serial number.

<Quidway> display elabel backplane
Info: It is executing, please wait…
[BackPlane_1]
/$[ArchivesInfo Version]
/$ArchivesInfoVersion=3.0
[Board Properties]
BoardType=EH02BAKK
BarCode=2102113089P0BB000881
Item=02113089
……………

  • In a cluster:

Log in to the master switch through Telnet or the console interface, and then run the display elabel backplane chassis chassis-id command (chassis-id specifies the CSS ID of a member chassis) in the user view to display the electronic label information. The BarCode field in the command output shows the serial number of the specified chassis.

<Quidway> display elabel backplane chassis ?
INTEGER<1-2>  Chassis ID

<Quidway> display elabel backplane chassis 2
Info: It is executing, please wait…

[BackPlane_2]
/$[ArchivesInfo Version]
/$ArchivesInfoVersion=3.0

[Board Properties]
BoardType=EH02BAKK
BarCode=2102113089P0BB000881
Item=02113549
……………

NOTE:
The command syntax may differ in different software versions. You can enter a question mark (?) to obtain help information about the command and set the chassis ID according to the help information.

Obtaining the Serial Number of a Card
Log in to the master switch through Telnet or the console interface, and then run the display elabel command in the user view and specify a slot ID according to help information to display the electronic label of a card. The BarCode field in the command output shows the serial number of the card.

<Quidway> display elabel ?
<1-1>      The present chassis
backplane  Backplane
brief      Display information briefly
<Quidway> display elabel 1/?
<4,6-8>                              <CMU1>
<FAN1-FAN2>                          <PWR1-PWR2>
<Quidway> display elabel 1/6 brief
Info: It is executing、please wait…

[Slot_6]
/$[Board Integration Version]
/$BoardIntegrationVersion=3.0

[Main_Board]
/$[ArchivesInfo Version]
/$ArchivesInfoVersion=3.0

[Board Properties]
BoardType=ET1D2S08SX1E
BarCode=020LVF6TBB000043
Item=03020LVF
……………

NOTE:
The command syntax may differ in different software versions. You can enter a question mark (?) to obtain help information about the command and set the slot ID according to the help information.

Obtaining the Serial Number of a Power Module
Log in to the master switch through Telnet or the console interface, and then run the display elabel command in the user view and specify a slot ID according to help information to display the electronic label of a power module. The SN field in the command output shows the serial number of the power module.

<Quidway> display elabel ?
<1-1>      The present chassis
backplane  Backplane
brief      Display information briefly
<Quidway> display elabel 1/?
<5,8,13,16>                             <CMU1>
<FAN1-FAN5>                             <PWR1-PWR4>
<Quidway> display elabel 1/PWR1
Info: It is executing, please wait…

[Slot_21]
/$[Board Integration Version]
/$BoardIntegrationVersion=3.0

[Main_Board]
DATE=13_02_08
SN=A664A0212080086V0.9A

NOTE:
The command syntax may differ in different software versions. You can enter a question mark (?) to obtain help information about the command and set the power module ID according to the help information.

Obtaining the Serial Number of a Fan Module
Log in to the master switch through Telnet or the console interface, and then run the display elabel command in the user view and specify a slot ID according to help information to display the electronic label of a fan module. The BarCode field in the command output shows the serial number of the fan module.

<Quidway> display elabel ?
<1-1>      The present chassis
backplane  Backplane
brief      Display information briefly
<Quidway> display elabel 1/?
<5,8,13,16>                             <CMU1>
<FAN1-FAN5>                             <PWR1-PWR4>
<Quidway> display elabel 1/FAN2
Info: It is executing, please wait…

[Slot_18]
/$[Board Integration Version]
/$BoardIntegrationVersion=3.0

[Main_Board]
/$[ArchivesInfo Version]
/$ArchivesInfoVersion=3.0

[Board Properties]
BoardType=LE02FCMC
BarCode=2103010JTF0123456789
Item=02120995
……………

NOTE:
The command syntax may differ in different software versions. You can enter a question mark (?) to obtain help information about the command and set the fan module ID according to the help information.

Huawei popular switch models:

S2309TP-EI-AC

S2309TP-PWR-EI

S2700-9TP-SI-AC

S2700-9TP-EI-AC

S3328TP-EI-24S-AC

S3328TP-EI-AC

S3700-28TP-SI-AC

….

Huawei S5700 Series switch overview

The Huawei S5700 series Ethernet switches (S5700 for short) are next-generation energy-saving
switches developed by Huawei to meet the demand for high-bandwidth access and Ethernet multi-service aggregation. Based on cutting-edge hardware and Huawei Versatile Routing Platform (VRP) software, the S5700 provides a large switching capacity, high reliability (double power slots and hardware Ethernet OAM), and high-density GE ports to accommodate 10 Gbit/s upstream transmissions. It also supports Energy Efficient Ethernet (EEE) and iStack. The S5700 can be used in various enterprise network scenarios. For example, it can function as an access or aggregation switch on a campus network, a gigabit access switch in an Internet data center (IDC), or a desktop switch to provide 1000 Mbit/s access for terminals.

The S5700 is available in a lite (LI) series, a standard (SI) series, an enhanced (EI) series, and a hyper (HI) series.

Various Port Combinations
The S5700-EI, S5710-EI and S5720-EI support various extended subcards that provide high-density GE/10GE uplink ports. The flexible port combinations meet bandwidth expansion requirements, protecting customers’ investment.
Intelligent Stack The S5700 supports intelligent stack (iStack). This technology combines multiple switches into a logical switch. Member switches in a stack implement redundancy backup to improve device reliability and use inter-device link aggregation to improve link reliability. iStack provides high network scalability. You can increase ports, bandwidth, and processing capacity of a stack by simply adding member switches to the stack. iStack also simplifies device configuration and management. After a stack is set up, multiple physical switches are virtualized into one logical device. You can log in to any member switch in the stack to manage all the member switches in the stack.

The S5720-SI/S5720S-SI/S5720-EI/S5720-LI/S5720S-LI support stacking through electrical
ports.

 

GPON Networking Applications

Huawei GPON is a passive optical transmission technology that applies in FTTx solutions, including fiber to the building (FTTB), fiber to the curb (FTTC), fiber to the door (FTTD), fiber to the home (FTTH), fiber to the mobile base station (FTTM), fiber to the office (FTTO), and fiber to the WLAN (FTTW), for voice, data, video, private line access, and base station access services.

QQ图片20170630102602

The FTTx network applications in GPON access have the following in common: The data,
voice, and video signals of terminal users are sent to ONUs, where the signals are converted into Ethernet packets and then transmitted over optical fibers to the OLT using the GPON uplink ports on the ONUs. Then, the Ethernet packets are forwarded to the upper-layer IP network using the uplink port on the OLT.

FTTB/FTTC: The OLT is connected to ONUs in corridors (FTTB) or by the curb (FTTC)
using an optical distribution network (ODN). The ONUs are then connected to user
terminals using xDSL. FTTB/FTTC is applicable to densely-populated residential
communities or office buildings. In this scenario, FTTB/FTTC provides services of
certain bandwidth for common users.
FTTD: uses existing access media at user homes to resolve drop fiber issues in FTTH
scenarios.
FTTH: The Huawei OLT connects to Huawei ONTs at user homes using an ODN network. FTTH is
applicable to new apartments or villas in loose distribution. In this scenario, FTTH
provides services of higher bandwidth for high-end users.

FTTM: The OLT is connected to ONUs using an ODN network. The ONUs are then
connected to wireless base stations using E1. The OLT connects wireless base stations to
the core IP bearer network using optical access technologies. This implementation mode
is not only simpler than traditional SDH/ATM private line technologies, but also drives
down the costs of base station backhaul. FTTM is applicable to reconstruction and
capacity expansion of mobile bearer networks. In this scenario, FTTM converges the
fixed network and the mobile network on the bearer plane.
FTTO: The OLT is connected to enterprise ONUs using an ODN network. The ONUs are
connected to user terminals using FE, POTS, or Wi-Fi. QinQ VLAN encapsulation is
implemented on the ONUs and the OLT. In this way, transparent and secure data
channels can be set up between the enterprise private networks located at different places, and therefore the service data and BPDUs between the enterprise private networks can be transparently transmitted over the public network. FTTO is applicable to enterprise networks. In this scenario, FTTO implements TDM PBX, IP PBX, and private line service in the enterprise intranets.
FTTW: The OLT connects to ONUs using an ODN network, the ONUs connect to access
points (APs) using GE for WLAN traffic backhaul. FTTW is the trend in Wi-Fi
construction.

Huawei S6700 hardware information

Hardware modules of the S6700 refer to the SCU (Switch Control Unit), power supply, and
fan.

QQ图片20170628154147

SCU

The SCU is fixed on the Huawei S6700. Each S6700 has one SCU.
The SCU is responsible for packet switching and device management. It integrates multiple functional modules, namely, the main control module, switching module, and interface module.

The main control module implements the following functions:
Processing protocols
Functioning as an agent of the user to manage the system and monitor the system
performance according to instructions of the user, and report the running status of the
device to the user
Monitoring and maintaining the interface module and switching module on the SCU
Switching Module
The switching module, also called the switching fabric, is responsible for packet exchange,
multicast replication, QoS scheduling, and access control on the interface module of the SCU.
The switching module adopts high performance chips to implement line-speed forwarding and fast switching of data with different priorities.
Interface Module
The interface module provides Ethernet interfaces for accessing Ethernet services.

Power Supply

For details about S6700 power supply configuration, see S6700 Hardware Description –
Power Modules.

Cards

The S6700 supports service cards. Service cards allow flexible networking and provide cost-effective and customized solutions.

S6720-30C-EI-24S-AC

S6720-54C-EI-48S-AC

S6720-54C-EI-48S-DC

S6700-24-EI