How to Increase WiFi Speed (WLAN FAT AP)
- About This Document
- Applicable Scenario
- Understanding the Theoretical WiFi Speed
- How to Test WiFi Speed
- Why Is My WiFi So Slow
- Three Simple Moves to Quickly Speed Up Your WiFi
- Seven Easy Steps to Maximize Your WiFi
- Slow WiFi Speed Due to Poor WiFi Signal Strength
- Slow WiFi Speed Due to Possible Misconfigurations of WEP/WPA/WPA2 Encryption (WEP vs WPA & WPA vs WPA2)
- Slow WiFi Speed Due to the WLAN Rate Limiting Configuration
- Slow WiFi Speed Because STAs Are Going Offline
- Web Pages Fail to Be Opened, and the Message "DNS Server Not Responding" Is Displayed
- Web Pages Load Slowly, and Packet Loss Occurs in a Ping Test
- Video Freezing Occurs, Which May Be Caused by the Disabling of Multicast IGMP Snooping
- Collecting Information About the Slow WiFi Speed Issue
- Continue Reading About WiFi
About This Document
To make your Wi-Fi network faster and easier to use, this document provides a set of common troubleshooting methods for slow Internet access through a WLAN provided by AR routers. If you encounter this issue when connecting to the Internet in wired mode through an AR router, resolve the problem by referring to Slow Internet Access in the Troubleshooting Insights.
Applicable Scenario
An AR router can work in either AC or Fat AP mode to provide WLAN services. These two modes apply to different scenarios.
- The AC mode applies to large-scale venues such as waiting halls and stadiums. In this mode, an AR router functions as an AC and provides access to downlink Fit APs. The AR router and Fit APs together provide WLAN access for STAs.
- The Fat AP mode applies to small-sized enterprises, homes, cafes, SOHO offices, and enterprise branches where WLAN services are deployed independently. In this mode, an AR router functions as a Fat AP and independently provides WLAN access for STAs.
The following describes how to locate and rectify the fault of slow WiFi access in small-scale places. For details about how to locate and rectify the fault of slow Wi-Fi access in large-scale venues such as waiting halls and stadiums, see How to Increase WiFi Speed (WLAN AC).
Typical Networking for Small-Scale Places
On a WLAN for a small-scale place, an AR router is deployed as a Fat AP to provide wireless services for STAs, without the need to deploy a separate authentication server or NMS. Figure 1-1 shows the typical networking.
How to Determine the Working Mode of an AR Router
- Check the model name of an AR router. By default, an AR router with the letter W contained in its model name works in Fat AP mode, and that without the letter W contained in its model name works in AC mode.
- If you are not sure whether the default configuration has been modified, log in to the router and run the display workmode wlan command to check its working mode.
<Huawei> display workmode wlan Wlan Current WorkMode = ap Wlan Config WorkMode = ap //ap indicates the Fat AP mode, and ac indicates the AC mode.
- If the AR router does not work in Fat AP mode, run the set workmode wlan command to set the working mode to Fat AP.
<Huawei> system-view [Huawei] set workmode wlan ap Warning: The WorkMode Change will be activated after board reboot. Continue? [y/n]:y [Huawei] quit <Huawei> reboot fast System will reboot! Continue ? [y/n]:y Info: system is rebooting ,please wait...
For details about how to log in to an AR router using the CLI, see How to Log In to the AR Router Through the Console Port (CLI) and How to Log In to the Router Through the Mini USB Port (CLI) in How to Log In to an AR Router Through the Web and CLI.
Understanding the Theoretical WiFi Speed
With the popularity of wireless networks, more and more small-scale places, such as homes, cafes, and shops, provide WiFi access for users. In daily life, everyone may have encountered slow web page loading or video freezing when connecting to the Internet through WiFi, with their wireless terminals (such as mobile phones, PCs, and tablets). For example, many have wondered why their mobile phones become unresponsive during Internet access even with 200 Mbit/s bandwidth. Before answering this question, let's get familiar with some terms closely related to the WiFi speed.
Term |
Description |
Example |
|---|---|---|
Downlink speed |
As shown in Figure 1-2, the downlink speed is the speed at which the Internet sends traffic to you for such services as browser opening or file downloading, and is expressed in Mbit/s. In this document, the downlink speed is the bandwidth that a user subscribes to from a broadband carrier. |
When a user subscribes to a 200 Mbit/s broadband package, it means that 200 Mbit/s is the downlink speed. |
Wireless link speed negotiated between a wireless router and a STA |
This speed is also referred to the wireless link speed, as shown in Figure 1-2. After a STA connects to a WLAN, it negotiates the wireless link speed with the associated wireless router, in Mbit/s. The wireless link speed is the maximum transmission speed that is supported by both the STA and router. |
Assume that a wireless router supports a transmission speed of 300 Mbit/s and the wireless network adapter of a STA supports a transmission speed of 150 Mbit/s. After they set up a wireless link, they will negotiate the wireless link speed to 150 Mbit/s. |
Theoretical WiFi speed |
This speed refers to the maximum data transmission speed when a STA accesses the Internet through a WLAN, in Mbit/s. The theoretical Wi-Fi speed is the smaller value between the downlink speed and the wireless link speed. |
If the downlink speed is 200 Mbit/s and the wireless link speed is 150 Mbit/s, the theoretical Wi-Fi speed is 150 Mbit/s. |
Theoretical WiFi download speed |
This speed refers to the speed for file downloading or video streaming by STAs, in MB/s. As 1 byte equals 8 bits, the theoretical WiFi download speed and the theoretical WiFi speed are in the proportion of 1:8. |
When the theoretical WiFi speed is 200 Mbit/s, the theoretical WiFi download speed is 25 MB/s. |
How to Test WiFi Speed
A broadband network is an extremely complex end-to-end system, which consists of the client, access network, core network, and content resources. The client refers to the network set up between STAs and wireless routers. Devices on the access and core networks between optical modems and the Internet are provided by carriers and are irrelevant to users. According to user feedback, the slow Internet access issue is mostly caused by clients. If you encounter slow Internet access using WiFi, a WiFi speed test is recommended at first.
Hardware Requirements for Different WiFi Speeds
Slow Internet access issues caused by clients can be classified into three types: hardware, software, and configuration issues. We can rectify software and configuration issues, but not hardware issues. To resolve hardware issues, replacing the hardware is the only choice. Therefore, before a WiFi network speed test, verify that the hardware configuration meets the requirements.
As broadband technologies continuously develop, 100 Mbit/s networks become widespread now. Table 1-2 describes hardware requirements for the 100 Mbit/s WiFi speed.
Hardware |
Requirements |
Description |
Remarks |
|---|---|---|---|
Wired interface on a wireless router |
1000 Mbit/s WAN or LAN interface |
A 100 Mbit/s interface can transmit only traffic at a speed of lower than 100 Mbit/s. To transmit traffic at a speed of higher than 100 Mbit/s, the router must have a 1000 Mbit/s interface. |
For wired interface parameters supported by AR routers, check the router product documentation or official website. Assume that an AR101W-S is used. You can check its wired interface parameters in Interface Description > GE electrical interface in the Huawei ARS Product Documentation. |
Wireless interface on a wireless router |
|
The maximum transmission speed supported by a wireless router is subject to the wireless protocol it supports. For 802.11n/ac, the maximum speeds supported in different MIMO modes and at different frequency bandwidths are as follows:
Some dual-band routers can combine the speeds on the 2.4 GHz and 5.0 GHz frequency bands to achieve a higher speed. For example, a router may support a speed of up to 1167 Mbit/s by combining 300 Mbit/s on 2.4 GHz and 867 Mbit/s on 5.0 GHz. |
For wireless interface parameters supported by AR routers, check the router product documentation or official website. Assume that an AR101W-S is used. You can check its wireless interface parameters in Interface Description > WiFi antenna interface in the Huawei ARS Product Documentation. |
Wireless network adapter of a STA |
|
The wireless parameters of a STA's wireless network adapter must match those of the wireless router. Otherwise, the wireless link speed negotiated between the STA and router is low, and the WiFi speed is affected. |
For WiFi parameters supported by a STA, check its product description or official website. For example, you can find WiFi parameters of Huawei's smartphone Mate 30 Pro 5G from SPECIFICATIONS > NETWORK on Huawei Vmall. |
Optical modem |
Gigabit optical modem |
Generally, optical modems are provided by carriers. If optical modems are not available, you can purchase them by yourself. |
None |
Ethernet cable |
Category 5 enhanced (Cat 5e) cables or higher |
Category 5 (Cat 5) or higher Ethernet cables apply to 100 Mbit/s networks, but they have been mostly replaced by Cat 5e cables. Therefore, Cat 5e cables be recommended. |
None |
WiFi Speed Test Method
Similar to broadband speed testing, WiFi speed tests can be carried out in online (websites) or local (tools) mode. The test result varies with the speed test method. It is recommended that the WiFi speed be tested using different methods for multiple times.
- For PCs, speed test websites are recommended, for example, carriers' or dedicated speed test websites.
- For mobile phones or tablets, local speed test tools are recommended. Download an app for WiFi speed test from AppGallery or App Store and install it to test the WiFi speed.
WiFi Speed Evaluation Criteria
Based on live network experiences, we summarize some recommended WiFi speed evaluation criteria, as listed in Table 1-3.
Theoretical WiFi Speed (Mbit/s) |
Theoretical WiFi Download Speed (MB/s) |
Slow (< 60% of the Theoretical WiFi speed) |
Normal (60% to 80% of the Theoretical WiFi speed) |
Good (> 80% of the Theoretical WiFi speed) |
|---|---|---|---|---|
10 |
1.25 |
< 6 Mbit/s bandwidth |
6–8 Mbit/s bandwidth |
> 8 Mbit/s bandwidth |
20 |
2.5 |
< 12 Mbit/s bandwidth |
12–16 Mbit/s bandwidth |
> 16 Mbit/s bandwidth |
50 |
6.25 |
< 30 Mbit/s bandwidth |
30–40 Mbit/s bandwidth |
> 40 Mbit/s bandwidth |
100 |
12.5 |
< 60 Mbit/s bandwidth |
60–80 Mbit/s bandwidth |
> 80 Mbit/s bandwidth |
200 |
25 |
< 120 Mbit/s bandwidth |
120–160 Mbit/s bandwidth |
> 160 Mbit/s bandwidth |
300 |
37.5 |
< 180 Mbit/s bandwidth |
180–240 Mbit/s bandwidth |
> 240 Mbit/s bandwidth |
500 |
62.5 |
< 300 Mbit/s bandwidth |
300–400 Mbit/s bandwidth |
> 400 Mbit/s bandwidth |
- Some speed test software may measure the WiFi download speed in the unit of MB/s, and will convert the unit into Mbit/s before displaying the test results. If the test results are still displayed in the unit of MB/s, multiply the value by 8 to obtain the actual WiFi speed in the unit of Mbit/s.
- The theoretical Wi-Fi speed is the smaller value between the downlink speed and the wireless link speed. For example, if the downlink speed is 200 Mbit/s and the wireless link speed negotiated between the router and STA is 300 Mbit/s, the theoretical Wi-Fi speed is 200 Mbit/s.
Why Is My WiFi So Slow
After analyzing numerous actual cases on live networks, we have summarized seven typical reasons for the slow WiFi speed issue, as shown in Figure 1-4.
Three Simple Moves to Quickly Speed Up Your WiFi
Quickly improving the WiFi speed can help customers restore the network services as soon as possible and rectify faults, which, however, will impose impact on running services. For example, restarting a device may interrupt current services. To minimize the impact, perform operations for speeding up your WiFi during off-peak hours. For any operation on the web system, see Logging In to an AR Router Through a Web System in the How to Configure an AR Router.
No. |
Handling Measure |
Remarks |
|---|---|---|
1 |
Remove obstacles or interference sources around the router to keep it away from walls, microwave ovens, and metal objects. Adjust positions of WiFi antennas. For details, see Slow WiFi Speed Due to Poor WiFi Signal Strength. |
None |
2 |
Power off and restart the router. Save the configuration before the restart upon power-off to prevent configuration loss. In practice, the auto-save function is enabled to prevent configuration loss upon power-off.
|
Restarting the router interrupts user services for 1 to 2 minutes. |
3 |
Reset the WiFi parameters of the router. Before resetting the WiFi parameters, delete the existing WiFi parameter settings.
|
|
4 |
Contact technical support engineers. For details, see Collecting Information About the Slow Wi-Fi Speed Issue. |
None |
Seven Easy Steps to Maximize Your WiFi
Slow WiFi Speed Due to Poor WiFi Signal Strength
Context
As WLANs use radio signals to transmit service data, radio waves in the air are attenuated due to the impact of the surrounding environment. If the WiFi speed is slow, check the WiFi signal strength. The strength of WiFi signals received by a STA directly affects the WiFi speed.
After the STA is connected to a WLAN, the number of signal bars displayed on the STA directly shows the strength of the current WiFi signal. Generally, three or four bars indicate that the WiFi signal strength is normal, and zero to two bars indicate that the WiFi signal strength is poor. If the strength of signals received by the STA is poor, perform the following operations for troubleshooting:
Troubleshooting Procedure
- Verify that WiFi antennas are correctly installed and no obstacle exists around an AR router.
- Ensure that WiFi antennas are securely tightened, as shown in Figure 1-5.
- To better receive and transmit WiFi signals, keep the WiFi antennas vertical to the ground, as shown in Figure 1-6.
- Place the router in an open area without obstacles or interference sources (such as walls and metal objects). Do not access a WLAN from a faraway location.
- Check for interference to 2.4 GHz or 5 GHz radio signals.Use dedicated WiFi signal test software to check the interference to radio signals, and observe the signal strength and co-channel or adjacent-channel interference.
- If radio signals are severely interfered, perform manual radio calibration.
<Huawei> system-view [Huawei] wlan ap [Huawei-wlan-view] calibrate enable manual [Huawei-wlan-view] calibrate manual startup
- If severe signal interference still persists after manual radio calibration, change the router's working channel.
<Huawei> system-view [Huawei] interface wlan-radio 0/0/0 [Huawei-Wlan-Radio0/0/0] channel 20mhz 6 //Change to channel 6.
- If the router supports the 5 GHz frequency band, enable the WLAN function on the 5 GHz frequency band. Enable the WLAN function on the 5 GHz radio interface wlan-radio 0/0/1 so that high bandwidth on the 5 GHz frequency band is leveraged to forward services. Set the operating channel bandwidth of the 5 GHz radio to 80 MHz to provider a higher speed. For WLAN configurations on this frequency band, see those on the 2.4 GHz frequency band.
<Huawei> system-view [Huawei] interface wlan-radio 0/0/1 //wlan-radio0/0/1 indicates the 5 GHz radio interface, and wlan-radio0/0/0 indicates the 2.4 GHz radio interface. [Huawei-Wlan-Radio0/0/1] channel 80mhz 40
- If radio signals are severely interfered, perform manual radio calibration.
- Verify that the power level of WLAN radios is 0.Run the display actual channel-power command to check the power level of radios.
<Huawei> display actual channel-power interface wlan-radio0/0/0 //Check the power level of the 2.4 GHz radio. -------------------------------------------------------- RADIO CHANNEL POWER-LEVEL POWER(dBm) CHANNEL-BANDWIDTH -------------------------------------------------------- 0/0 1 0 20 20MHz -------------------------------------------------------- <Huawei> display actual channel-power interface wlan-radio0/0/1 //Check the power level of the 5 GHz radio. -------------------------------------------------------- RADIO CHANNEL POWER-LEVEL POWER(dBm) CHANNEL-BANDWIDTH -------------------------------------------------------- 0/1 1 0 20 20MHz --------------------------------------------------------
POWER-LEVEL indicates the actual transmit power level of a radio. The value ranges from 0 to 12, and a larger value indicates a lower transmit power. In normal cases, the value of POWER-LEVEL is 0, indicating that a radio interface transmits signals at full power. If the value of POWER-LEVEL is not 0, run the following commands to set the power level to 0:<Huawei> system-view [Huawei] interface wlan-radio 0/0/0 [Huawei-Wlan-Radio0/0/0] power-level 0 [Huawei-Wlan-Radio0/0/0] quit [Huawei] wlan ap [Huawei-wlan-view] radio-profile name radio-1 [Huawei-wlan-radio-prof-radio-1] power-mode fixed //Set the power mode of a radio to fixed to make the configured power level take effect.
Slow WiFi Speed Due to Possible Misconfigurations of WEP/WPA/WPA2 Encryption (WEP vs WPA & WPA vs WPA2)
Context
WLANs are easy to deploy and expand, flexible, and cost-effective. However, as WLANs use transmit data on open wireless channels through radio signals, service data may easily be intercepted or tampered with by attackers. To ensure WLAN access security, AR routers provide four security policies, namely, Wired Equivalent Privacy (WEP), WiFi Protected Access (WPA), WPA2, and WLAN Authentication and Privacy Infrastructure (WAPI). The Temporary Key Integrity Protocol (TKIP) encryption mode in WEP and WPA/WPA2 is not recommended in practice because this mode uses the Rivest Cipher 4 (RC4) algorithm, which is insecure and affects the wireless link speed. Small-scale networks do not have high security requirements, and the Counter Mode with the CBC-MAC Protocol (CCMP) encryption mode in WPA/WPA2 will suffice.
Troubleshooting Procedure
- Check the encryption mode configured on the router. Run the display this command in the WLAN security profile view to check the WLAN encryption configuration.
- Information similar to the following indicates that the WEP security policy is configured. You are advised to change it to WPA/WPA2 by referring to Step 2.
<Huawei> system-view [Huawei] wlan ap [Huawei-wlan-view] security-profile id 0 [Huawei-wlan-sec-prof-secf] display this # wep authentication-method share-key wep key wep-40 pass-phrase 0 cipher %^%#01R+4P/4OQ['JySRg$z)3"'mUkcF-7''[z8(J5@H%^%# #
- Information similar to the following indicates that the WPA security policy is configured, with TKIP encryption in use. You are advised to change the encryption mode to CCMP by referring to Step 2.
<Huawei> system-view [Huawei] wlan ap [Huawei-wlan-view] security-profile id 1 [Huawei-wlan-sec-prof-sec1] display this # security-policy wpa wpa authentication-method psk pass-phrase cipher %^%#y4C0!,]\XFAkPvMtKV}(FQ1sS$FRj3<FaB5u~}j=%^%# encryption-method tkip #
- Information similar to the following indicates that the WPA2 security policy is configured, with TKIP encryption in use. You are advised to change the encryption mode to CCMP by referring to Step 2.
<Huawei> system-view [Huawei] wlan ap [Huawei-wlan-view] security-profile id 2 [Huawei-wlan-sec-prof-sec2] display this # security-policy wpa2 wpa2 authentication-method psk pass-phrase cipher %^%#dwU|Qf=Q)<n.Ie<n@x,.99P!.JnW[,iHLJ,eYIaC%^%# encryption-method tkip #
- Information similar to the following indicates that the WEP security policy is configured. You are advised to change it to WPA/WPA2 by referring to Step 2.
- Configure the WPA2 security policy and CCMP encryption.
<Huawei> system-view [Huawei] wlan ap [Huawei-wlan-view] security-profile name security-1 [Huawei-wlan-sec-prof-security-1] wpa2 authentication-method psk pass-phrase cipher huawei@123 encryption-method ccmp
Slow WiFi Speed Due to the WLAN Rate Limiting Configuration
Context
In WiFi access scenarios, rate limiting may be configured to protect network bandwidth resources, which in turn affects the WiFi speed of STAs. Therefore, upon a slow WiFi speed, check whether the WLAN rate limiting function is configured on an AR router.
Troubleshooting Procedure
- Check whether the WLAN rate limiting function is configured.Run the display traffic-profile name profile-name command to check the configuration of the traffic profile.
<Huawei> display traffic-profile name traffic-1 Profile ID : 1 Profile name : traffic-1 Client Limit Rate : 64 Kbps(up) //The value is not the maximum value 4294967295, indicating that rate limiting is configured. : 4294967295 Kbps(down) VAP Limit Rate : 128 Kbps(up) //The value is not the maximum value 4294967295, indicating that rate limiting is configured. : 4294967295 Kbps(down) 802.1p Mapping Mode: mapping ---------------------------- User-priority 802.1p 0 0 1 1 2 2 3 3 4 4 ...... ----------------------------If the WLAN rate limiting function is configured on the router, perform the following operations to cancel this configuration:<Huawei> system-view [Huawei] wlan ap [Huawei-wlan-view] traffic-profile name traffic-1 [Huawei-wlan-traffic-prof-traffic-1] undo rate-limit vap up //Cancel the rate limit for all STAs on a VAP. [Huawei-wlan-traffic-prof-traffic-1] undo rate-limit client up //Cancel the rate limit for a STA on a VAP.
Slow WiFi Speed Because STAs Are Going Offline
Context
In wired scenarios, to defend against ARP address spoofing attacks, we usually configure ARP entry fixing on an AR router. Then the router can determine whether to update ARP entries based on whether the MAC addresses in the received ARP packets match those in the ARP table. However, in wireless scenarios, STAs may change flexibly, and their MAC addresses and access locations change frequently. If ARP entry fixing is configured, STAs will go offline due to abnormal ARP learning. If a STA goes offline, web pages may be opened slowly or fail to be opened on the STA.
Troubleshooting Procedure
- Check whether ARP entry fixing is configured on the router.Run the display arp anti-attack configuration entry-check command to check the ARP entry fixing mode. disabled indicates that ARP entry fixing is disabled on the router.
<Huawei> display arp anti-attack configuration entry-check ARP anti-attack entry-check mode: disabled
If the ARP entry fixing mode is not disabled, run the following commands to disable ARP entry fixing:
<Huawei> system-view [Huawei] undo arp anti-attack entry-check enable
Web Pages Fail to Be Opened, and the Message "DNS Server Not Responding" Is Displayed
Context
Control Plane Committed Access Rate (CPCAR) rate-limits protocol packets sent to the CPU, so that CPU resources are not occupied, preventing impact on other services. Different CPCAR values can be set for different protocol types. Packets whose rate exceeds the CPCAR value are discarded.
On a WLAN, the most likely protocol packets to be discarded are DNS Request and ARP Request packets. The reasons are as follows:
- When accessing the URL of a website through a WLAN, a STA sends a DNS Request packet to the DNS server. The DNS server can be a DNS server on the public network or a gateway. When the DNS server functions as a gateway, a large number of DNS Request packets are generated if a large number of STAs access the network. When the number of DNS Request packets received by an AR router serving as the DNS server and gateway exceeds the CPCAR value, the router randomly discards the DNS Request packets. If the DNS Request packet of a STA is discarded, the DNS server will not respond to the STA. As a result, the requested web page loads slowly or fails to load.
- On a WLAN, some STAs scan LAN segments and send ARP Request packets to all IP addresses on their local LANs. When the number of ARP Request packets received by the router exceeds the CPCAR value, the router randomly discards the ARP Request packets. If the ARP Request packet of a STA is discarded, the router cannot learn its ARP entry. As a result, the requested web page loads slowly. If the router keeps failing to learn ARP entries of the STA, the STA cannot access web pages.
Troubleshooting Procedure
- Check whether DNS or ARP Request packets are discarded on the router.Run the display cpu-defend statistics command for multiple times to check whether the Drop Packets values corresponding to arp-request and dns-request change.
<Huawei> display cpu-defend statistics ------------------------------------------------------------------ Packet Type Pass Packets Drop Packets ------------------------------------------------------------------- 8021X 0 0 arp-miss 5 0 arp-reply 8090 0 arp-request 1446576 127773 …… dns-request 12465 1177 fib-hit 0 0 fr 0 0 ftp-client 0 0 ftp-server 0 0 fw-dns 0 0 fw-ftp 0 0 …… -------------------------------------------------------------------
If the Drop Packets value corresponding to arp-request keeps increasing, ARP Request packets are discarded. In this case, run the following commands to change the CPCAR value to 512 for ARP Request packets.<Huawei> system-view [Huawei] cpu-defend policy arp [Huawei-cpu-defend-policy-arp] packet-type arp-request rate-limit 512 [Huawei-cpu-defend-policy-arp] quit [Huawei] cpu-defend-policy arp
If the Drop Packets value corresponding to dns-request keeps increasing, DNS Request packets are discarded. In this case, run the following commands to change the CPCAR value to 512 for DNS Request packets.
<Huawei> system-view [Huawei] cpu-defend policy dns [Huawei-cpu-defend-policy-dns] packet-type dns-request rate-limit 512 [Huawei-cpu-defend-policy-dns] quit [Huawei] cpu-defend-policy dns
After the fault is rectified, you are advised to delete cpu-defend policy dns and cpu-defend policy arp commands to restore default CPCAR values for ARP and DNS Request packets in order to protect CPU resources.
By default, the CPU attack defense policy default is applied to the router. The CPCAR values of various protocols have been specified in the CPU attack defense policy default and cannot be modified.
- Check whether the DNS proxy function is configured.
If DNS Request packets are discarded on the router, check whether the DNS proxy function is configured on the router. With this function, the gateway sends DNS Request packets from STAs to the CPU for processing, which aggravates discarding of DNS Request packets. Therefore, if DNS Request packets are discarded, deleting the DNS proxy configuration is recommended. Configure the DHCP function on the router to deliver the IP address of the DNS server on the public network to STAs so that the STAs can send DNS Request packets to the DNS server on the public network.
To check the DNS configuration, run the display current-configuration | include dns command.<Huawei> display current-configuration | inc dns dns resolve dns server x.x.x.x //x.x.x.x specifies the IP address of the DNS server on the public network. dns proxy enable //The DNS proxy function is configured. dns relay enable //The DNS relay function is configured. dhcp server dns-list y.y.y.y //DNS server address delivered to STAs. y.y.y.y specifies the IP address of the gateway interface.
If the preceding configuration is displayed, the DNS proxy function is configured on the router. In this case, delete the DNS proxy configuration and deliver the IP address of the DNS server on the public network to STAs through the DHCP function.<Huawei> system-view [Huawei] undo dns proxy enable [Huawei] undo dns resolve [Huawei] undo dns server x.x.x.x [Huawei] interface vlanif 100 [Huawei-Vlanif100] undo dhcp server dns-list y.y.y.y [Huawei-Vlanif100] dhcp server dns-list x.x.x.x //Deliver the IP address of the DNS server on the public network to STAs in a VLANIF interface address pool.
Web Pages Load Slowly, and Packet Loss Occurs in a Ping Test
Context
If a STA is online on an AR router but cannot access the Internet, ping the IP address of the STA from the AR router to check whether packet loss occurs between the STA and the AR router. If the ping operation fails or some packets are lost, perform the following operations for troubleshooting:
- Check whether strict ARP learning is configured on the router. With strict ARP learning enabled on the router, it learns ARP entries only when receiving ARP Reply packets in response to ARP Request packets sent by itself. The router will not learn the ARP entry of a STA when receiving an ARP Request packet initiated by the STA. As a result, the router cannot ping the STA, and the STA fails to access web pages.
- Check whether an IP address conflict occurs on the network. When an attack occurs on the network, an IP address conflict may occur. The IP address conflict will lead to frequent route flapping on the router and cause packets to be sent to an incorrect STA. As a result, some packets are lost during the ping operation between the STA and the router, and web pages load slowly on the STA.
Troubleshooting Procedure
- Check whether strict ARP learning is configured on the router.Run the display arp learning strict command to check the configuration of strict ARP learning.
<Huawei> display arp learning strict The global configuration:arp learning strict //If no information is displayed following arp learning strict, strict ARP learning is disabled. Interface LearningStrictState ------------------------------------------------------------ Vlanif100 force-disable //force-disable indicates that strict ARP learning is disabled on the interface. Vlanif200 force-enable //force-enable indicates that strict ARP learning is enabled on the interface. ------------------------------------------------------------ Total:2 Force-enable:1 Force-disable:1
If strict ARP learning is configured on the device, perform the following operations to disable strict ARP learning in the system view and interface view in sequence:<Huawei> system-view [Huawei] undo arp learning strict [Huawei] interface vlanif 200 [Huawei-Vlanif200] undo arp learning strict
- Check whether the STA encounters an IP address conflict.In most cases, IP addresses of STAs are automatically assigned from an address pool of the VLANIF interface. Run the display ip pool interface interface-pool-name conflict command to check information about conflicting IP addresses in the address pool.
<Huawei> display ip pool interface Vlanif100 conflict Pool-name : Vlanif100 Pool-No : 1 Lease : 1 Days 0 Hours 0 Minutes …… Client-ID format as follows: DHCP : mac-address PPPoE : mac-address IPSec : user-id/portnumber/vrf PPP : interface index L2TP : cpu-slot/session-id SSL-VPN : user-id/session-id ---------------------------------------------------------------- Index IP Client-ID Type Left Status ---------------------------------------------------------------- 109 192.168.10.20 - - - Conflict ----------------------------------------------------------------
After finding the conflicting IP address, locate the MAC address mapping this IP address so as to locate the STA and manually change its IP address. The following methods are available for you to locate the MAC address of a STA with a conflicting IP address.
- The router records IP-MAC mappings for STAs it has learned in its ARP entries, including the STAs with conflicting IP addresses. Run the display arp command on the router to check ARP entries to find the MAC address mapping the conflicting IP address.
<Huawei> display arp IP ADDRESS MAC ADDRESS EXPIRE(M) TYPE INTERFACE VPN-INSTANCE VLAN/CEVLAN(SIP/DIP) PVC ------------------------------------------------------------------------------ 10.10.10.1 xxxx-xxxx-xxxx I - GE0/0/5 10.10.10.214 yyyy-yyyy-yyyy 4 D-0 GE0/0/5 …… 192.168.10.20 zzzz-zzzz-zzzz I - GE0/0/3 - If the corresponding ARP entry is aged and no related information can be found, check logs about IP address conflicts. Run the display logbuffer command to view log information recorded in the log buffer. Search for AM/4/IPCONFLICTDTC in the log to view the MAC address mapping the conflicting IP address.
<Huawei> display logbuffer Logging buffer configuration and contents: enabled Allowed max buffer size: 1024 Actual buffer size: 512 Channel number: 4, Channel name: logbuffer Dropped messages: 0 Overwritten messages: 3315 Current messages: 512 Apr 3 2020 13:46:15+00:00 Huawei %%01DEFD/4/CPCAR_DROP_MPU(l)[0]:Some packets a re dropped by cpcar on the MPU. (Packet-type=arp-request, Drop-Count=14428) Apr 3 2020 13:36:15+00:00 Huawei %%01DEFD/4/CPCAR_DROP_MPU(l)[1]:Some packets a re dropped by cpcar on the MPU. (Packet-type=arp-request, Drop-Count=16593) Apr 3 2020 13:26:15+00:00 Huawei %%01DEFD/4/CPCAR_DROP_MPU(l)[2]:Some packets a re dropped by cpcar on the MPU. (Packet-type=arp-request, Drop-Count=922) ......
- The router records IP-MAC mappings for STAs it has learned in its ARP entries, including the STAs with conflicting IP addresses. Run the display arp command on the router to check ARP entries to find the MAC address mapping the conflicting IP address.
Video Freezing Occurs, Which May Be Caused by the Disabling of Multicast IGMP Snooping
Context
In an HD VOD scenario, the multicast-to-unicast conversion function is required. After this function is enabled on an AR router, the router listens on IGMP Report and Leave messages to maintain multicast-to-unicast entries. Before sending a multicast packet to a STA, the router converts the packet into a unicast data packet according to the multicast-to-unicast entry, and sends the unicast packet to the STA. This prevents the router from sending multicast data packets to STAs that do not need the specified data, thereby improving transmission efficiency of multicast data streams.
Troubleshooting Procedure
- Check whether the multicast-to-unicast conversion function is enabled on the router.Run the display service-set id service-set-id command to check the configuration of multicast-to-unicast conversion in a service set.
<Huawei> display service-set id 0 ---------------------------------------------------------------------------- Service-set ID : 0 Service-Set name : a SSID : - Hide SSID : disable User isolate : disable Type : service Maximum number of user : 32 Association timeout(min) : 5 Traffic profile name : traf Security profile name : secf Wlan-bss interface : - Igmp mode : off //off indicates that the multicast-to-unicast conversion function is disabled. snooping indicates that the multicast-to-unicast conversion function is enabled. ----------------------------------------------------------------------------
If the multicast-to-unicast conversion function is disabled on the router, perform the following operations to enable the function:
<Huawei> system-view [Huawei] wlan ap [Huawei-wlan-view] service-set name huawei-1 [Huawei-wlan-service-set-huawei-1] igmp-mode snooping
Collecting Information About the Slow WiFi Speed Issue
- Collect fault information.
- Collect all diagnostic information and export the information to a file.
Run the display diagnostic-information file-name command in the user view to collect diagnostic information and save the information to a file.
<Huawei> display diagnostic-information dia-info.txt This operation will take several minutes, please wait......................... .................................................................. Info: The diagnostic information was saved to the device successfully..
- When the diagnostic file is generated, you can export the file from the device using TFTP, FTP, or SFTP. For details, see Local File Management.
You can run the dir command in the user view to check whether the file is generated.
You can also run the display diagnostic-information command and save STA logs in a diagnostic file on a disk. For details, see Diagnostic File Obtaining Guide.
If this command displays a long output, press Ctrl+C to abort this command.
The display diagnostic-information command displays diagnostic information, which helps locate faults but may affect system performance. For example, the CPU usage may become high. Therefore, do not use this command when the system is running properly.
Do not run the display diagnostic-information command simultaneously on multiple terminals connected to the device. This is because doing so may significantly increase the CPU usage of the device and deteriorate the device performance.
- Collect the log and trap information on the device and export the information to files.
Run the save logfile command in the user view to save the log and trap information in the buffer to files.
<Huawei> save logfile Info: It may take several seconds,please wait... Save log file successfully.
- When the diagnostic file is generated, you can export the file from the device using TFTP, FTP, or SFTP. For details, see Local File Management.
You can also run the display logbuffer and display trapbuffer commands to view the log and trap information on the device, and save STA logs in a diagnostic file on a disk. For details, see Diagnostic File Obtaining Guide.
- Collect all diagnostic information and export the information to a file.
- Seek technical support.
Click http://e.huawei.com/en/how-to-buy/contact-us to seek technical support.
Technical support personnel will provide instructions for you to submit all the collected information and files, so that they can locate faults.
Continue Reading About WiFi
This TechNote is intended for device maintenance personnel or personnel who have basic data communication knowledge and can independently locate WiFi faults. The concepts, principles, and configurations related to WiFi are not detailed in this document. Refer to the following for more information about WiFi:
AR Router Configuration Guide > WLAN-FAT AP Configuration Guide
AR Router CLI-based Typical Configuration Examples
AR Router Web-based Typical Configuration Examples
Refer to the following for more information about WiFi troubleshooting:
- About This Document
- Applicable Scenario
- Understanding the Theoretical WiFi Speed
- How to Test WiFi Speed
- Why Is My WiFi So Slow
- Three Simple Moves to Quickly Speed Up Your WiFi
- Seven Easy Steps to Maximize Your WiFi
- Slow WiFi Speed Due to Poor WiFi Signal Strength
- Slow WiFi Speed Due to Possible Misconfigurations of WEP/WPA/WPA2 Encryption (WEP vs WPA & WPA vs WPA2)
- Slow WiFi Speed Due to the WLAN Rate Limiting Configuration
- Slow WiFi Speed Because STAs Are Going Offline
- Web Pages Fail to Be Opened, and the Message "DNS Server Not Responding" Is Displayed
- Web Pages Load Slowly, and Packet Loss Occurs in a Ping Test
- Video Freezing Occurs, Which May Be Caused by the Disabling of Multicast IGMP Snooping
- Collecting Information About the Slow WiFi Speed Issue
- Continue Reading About WiFi