Rcv err cisco что это
| Сообщения без ответов | Активные темы | Текущее время: 23 дек 2021, 14:57 |
| Часовой пояс: UTC + 3 часа Критичны ли для Wi-Fi сети ошибки Rcv-Err UnderSize
| Добрый день, Схема простая. Как я понимаю это фреймы, размер которых менее 64 байт, хотя с другой стороны менее 64 байт быть никак не может. Вот show статистика с порта на Catalyst 3560 на котором висит WiFi: Switch3560#show interfaces counters errors Port Align-Err FCS-Err Xmit-Err Rcv-Err UnderSize Switch3560#show interfaces gigabitEthernet 0/1 Сначала грешил на физику, потом перековырял все настройки точки доступа, но никак не могу избавиться от ошибок ((( P.S. Просто настроил WiFi сеть, но никак не могу закрыть проект из за того что эти ошибки сыпятся. По факту когда пользователи работают через WiFi это незаметно.
| | Это интересно, нужно будет погуглиться на эту тему для весомости своих аргументов при закрытии проекта ))
| Сеть какая? Есил полудуплексные g или n, то немного битых фреймов ИМХО ошибкой не являются.
| Всем спасибо за помощь. Проблема с Rcv-Err UnderSize решена. Bug: Revised October 20, 2005 THIS FIELD NOTICE IS PROVIDED ON AN «AS IS» BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTY OF MERCHANTABILITY. YOUR USE OF THE INFORMATION ON THE FIELD NOTICE OR MATERIALS LINKED FROM THE FIELD NOTICE IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS FIELD NOTICE AT ANY TIME. Products Affected Problem Description The interface LED may also blink amber. No connectivity failures are experienced. All network traffic passes normally. Background The counting and reporting is erroneous. Network traffic is forwarded correctly. This problem does not affect network data, but solely the interface reporting. Problem Symptoms Workaround/Solution Cisco IOS release 12.1(19)EA1d Cisco IOS release 12.1(20)EA1a Cisco IOS release 12.1(22)EA1 or later Cisco IOS release 12.2(20)SE1 or later It is not necessary to upgrade to one of the fixed releases, as this problem is purely cosmetic and does not affect the functionality of the device. However, the false display of errors will not occur if an upgrade to one of these releases is performed. DDTS CSCec14238 (registered customers only) CSCec53648 (registered customers only) For More Information Troubleshooting Switch Port and Interface ProblemsAvailable LanguagesDownload OptionsContentsIntroductionThis document is intended to help determine why a port or interface experiences problems. This document applies to Catalyst switches that run CatOS Software on the Supervisor or Cisco IOS ® System Software on the Supervisor. PrerequisitesRequirementsThere are no specific requirements for this document. Components UsedThis document is not restricted to specific software and hardware versions. ConventionsRefer to Cisco Technical Tips Conventions for more information on document conventions. Physical Layer TroubleshootingUsing the LEDs to TroubleshootIf you have physical access to the switch, it can save time to look at the port LEDs which give you the link status or can indicate an error condition (if red or orange). The table describes the LED status indicators for Ethernet modules or fixed-configuration switches:
Ensure that both sides have a link. A single broken wire or one shutdown port can cause the problem where one side has a link light, but the other side does not. A link light does not guarantee that the cable is fully functional. The cable can have encountered physical stress that causes it to be functional at a marginal level. Normally you can identify this situation if the port has many packet errors, or the port constantly flaps (loses and regains link). Check the Cable and Both Sides of the ConnectionIf the link light for the port does not come on, you can consider these possibilities:
Ethernet Copper and Fiber CablesMake sure you have the correct cable for the type of connection you are making. Category 3 copper cable can be used for 10 Mbps unshielded twisted pair (UTP) connections, but must never be used for 10/100 or 10/100/1000Mbps UTP connections. Always use either Category 5, Category 5e, or Category 6 UTP for 10/100 or 10/100/1000Mbps connections. For fiber, make sure you have the correct cable for the distances involved and the type of fiber ports that are used. The two options are singlemode fiber (SMF) or multimode fiber (MMF). Make sure the ports on the devices that are connected together are both SMF, or both are MMF ports. Note: For fiber connections, make sure the transmit lead of one port is connected to the receive lead of the other port. Connections for transmit-to-transmit and receive-to-receive do not work. Ethernet and Fast Ethernet Maximum Transmission Distances
For more details on the different types of cables/connectors, cabling requirements, optical requirements (distance, type, patch cables, etc.), how to connect the different cables, and which cables are used by most Cisco switches and modules, refer to Catalyst Switch Cable Guide. Gigabit Ethernet TroubleshootingIf you have device A connected to device B over a Gigabit link, and the link does not come up, perform this procedure. Verify device A and B use the same GBIC, short wavelength (SX), long wavelength (LX), long haul (LH), extended wavelength (ZX), or copper UTP (TX). Both devices must use the same type of GBIC to establish link. An SX GBIC needs to connect with an SX GBIC. An SX GBIC does not link with an LX GBIC. Refer to Mode-Conditioning Patch Cord Installation Note for more information. Verify distance and cable used per GBIC as defined in this table. 1000BASE-T and 1000BASE-X Port Cabling Specifications The numbers given for multimode fiber-optic cable refer to the core diameter. For single-mode fiber-optic cable, 8.3 microns refers to the core diameter. The 9-micron and 10-micron values refer to the mode-field diameter (MFD), which is the diameter of the light-carrying portion of the fiber. This area consists of the fiber core plus a small portion of the surrounding cladding. The MFD is a function of the core diameter, the wavelength of the laser, and the refractive index difference between the core and the cladding. Distances are based on fiber loss. Multiple splices and substandard fiber-optic cable reduce cabling distances. When you use an LX/LH GBIC with 62.5-micron diameter MMF, you must install a mode-conditioning patch cord (CAB-GELX-625 or equivalent) between the GBIC and the MMF cable on both the transmit and receive ends of the link. The mode-conditioning patch cord is required for link distances less than 328 feet (100 m) or greater than 984 feet (300 m). The mode-conditioning patch cord prevents overdriving the receiver for short lengths of MMF and reduces differential mode delay for long lengths of MMF. Refer to Mode-Conditioning Patch Cord Installation Note for more information. Dispersion-shifted single-mode fiber-optic cable. The minimum link distance for ZX GBICs is 6.2 miles (10 km) with an 8-dB attenuator installed at each end of the link. Without attenuators, the minimum link distance is 24.9 miles (40 km). If either device has multiple Gigabit ports, connect the ports to each other. This tests each device and verifies that the Gigabit interface functions correctly. For example, you have a switch that has two Gigabit ports. Wire Gigabit port one to Gigabit port two. Does the link come up? If so, the port is good. STP blocks on the port and prevents any loops (port one receive (RX) goes to port two transmit (TX), and port one TX goes to port two RX). If single connection or Step 3 fails with SC connectors, loop the port back to itself (port one RX goes to port one TX). Does the port come up? If not, contact the TAC, as this can be a faulty port. If steps 3 and 4 are successful, but a connection between device A and B cannot be established, loop ports with the cable that adjoins the two devices. Verify that there is not a faulty cable. Verify that each device supports 802.3z specification for Gigabit auto-negotiation. Gigabit Ethernet has an auto-negotiation procedure that is more extensive than the one used for 10/100 Ethernet (Gigabit auto-negotiation spec: IEEE Std 802.3z-1998). When you enable link negotiation, the system auto-negotiates flow control, duplex mode, and remote fault information. You must either enable or disable link negotiation on both ends of the link. Both ends of the link must be set to the same value or the link cannot connect. Problems have been seen when you connect to devices manufactured before the IEEE 802.3z standard was ratified. If either device does not support Gigabit auto-negotiation, disable the Gigabit auto-negotiation, and it forces the link up. It takes 300msec for the card firmware to notify the software that a 10/100/1000BASE-TX link/port is down. The 300msec default debounce timer comes from the firmware polling timer to the linecards, which occurs every 300 msec. If this link is run in 1G (1000BASE-TX) mode, Gigabit sync, which occurs every 10msec, must be able to detect the link down faster. There is a difference in the link failure detection times when you run GigabitEthenet on copper versus GigabitEthernet over Fibre. This difference in detection time is based on the IEEE standards. In order to troubleshoot the error message: %SYS-4-PORT_GBICBADEEPROM: / %SYS-4-PORT_GBICNOTSUPP, refer to Common CatOS Error Messages on Catalyst 6000/6500 Series Switches. For GigabitEthernet system requirements as well as Gigabit Interface Converters (GBICs), Coarse Wavelength Division Multiplexing (CWDM), and Small Form-Factor Pluggable (SFP) system requirements, refer to these: Connected vs NotconnectedMost Cisco switches default to having a port in the notconnect state. This means it is currently not connected to anything, but it will connect if it has a good connection to another operational device. If you connect a good cable to two switch ports in the notconnect state, the link light must become green for both ports, and the port status must indicate connected. This means that the port is up as far as Layer 1 (L1) is concerned. For CatOS, you can use the show port command to verify whether the port has a connected or notconnect status, or whether it is another state that would cause connectivity to fail, like disabled or errdisable. For Cisco IOS, you can use the show interfaces command to verify whether the interface is «up, line protocol is up (connected)». The first «up» refers to the physical layer status of the interface. The «line protocol up» message shows the data link layer status of the interface and says that the interface can send and receive keepalives. If show port shows connected or show interfaces shows up/ line protocol up (connected) but you see errors incrementing in the output of either command, refer to the Understanding Specfic Port and Interface Counter Output for CatOS or Cisco IOS or Common Port and Interface Problems sections of this document for troubleshooting advice. Most Common Port and Interface Troubleshooting Commands for CatOS and Cisco IOSThis table shows the most common commands used for troubleshooting port or interface problems on switches that run CatOS Software on the Supervisor or Cisco IOS System Software on the Supervisor. Note: Choose a command in the left hand column to go to documentation for that command. The right hand column gives a brief description of what the command does and lists any exceptions to it’s use per platform. These commands are supported by the Output Interpreter tool for CatOS and can be used to assist in troubleshooting switch port or problems: show version, show module, show port, show counters , or show mac . If you have the output of the supported commands from your Cisco device, you can use to display potential issues and fixes. In order to use Output Interpreter, you must be a registered user, be logged in, and have JavaScript enabled.
Understanding Specific Port and Interface Counter Output for CatOS and Cisco IOSMost switches have some way to track the packets and errors that occur on a port or interface. The common commands used to find this type of information are described in the Most Common Port and Interface Troubleshooting Commands for CatOS and Cisco IOS section of this document. Note: There can be differences in the implementation of the counters across various platforms and releases. Although the values of the counters are largely accurate, they are not very precise by design. In order to pull the exact statistics of the traffic, it is suggested that you use a sniffer to monitor the necessary ingress and egress interfaces. Excessive errors for certain counters usually indicate a problem. When you operate at half-duplex setting, some data link errors incrementing in Frame Check Sequence (FCS), alignment, runts, and collision counters are normal. Generally, a one percent ratio of errors to total traffic is acceptable for half-duplex connections. If the ratio of errors to input packets is greater than two or three percent, performance degradation can be noticed. In half-duplex environments, it is possible for both the switch and the connected device to sense the wire and transmit at exactly the same time and result in a collision. Collisions can cause runts, FCS, and alignment errors due to the frame not being completely copied to the wire, which results in fragmented frames. When you operate at full-duplex, errors in FCS, Cyclic Redundancy Checks (CRC), alignment, and runt counters must be minimal. If the link operates at full-duplex, the collision counter is not active. If the FCS, CRC, alignment, or runt counters increment, check for a duplex mismatch. Duplex mismatch is a situation where the switch operates at full-duplex and the connected device operates at half-duplex, or vice versa. The results of a duplex mismatch are extremely slow performance, intermittent connectivity, and loss of connection. Other possible causes of data link errors at full-duplex are bad cables, faulty switch ports, or NIC software/hardware issues. See the Common Port and Interface Problems section of this document for more information. Show Port for CatOS and Show Interfaces for Cisco IOSThe show port Note: For 2900/3500XL Series switches use the show interfaces card-type The show interfaces command output up to this point is explained here (in order) : Note: Variables that can affect routing (for example, load and reliability) are not cleared when the counters are cleared. The purpose of SPD is to ensure that important control packets, such as routing updates and keepalives, are not dropped when the IP input queue is full. When the size of the IP input queue is between the minimum and maximum thresholds, normal IP packets are dropped based on a certain drop probability. These random drops are called SPD flushes. The rest of the show interfaces command displays error counter output which is similar or equivalent to CatOS error counter output. See Table 1 for explanations of the error counter output. Note: There is a difference between the counter of show interface command output for a physical interface and a VLAN interface. The input packet counters increment in the output of show interface for a VLAN interface when that packet is Layer 3 (L3) processed by the CPU. Traffic that is Layer 2 (L2) switched never makes it to the CPU and is not counted in the show interface counters for the VLAN interface. It would be counted on the show interface output for the appropriate physical interface. The show interfaces card-type CatOS error counter output for show port or show port counters for the Catalyst 6000, 5000 and 4000 Series. Cisco IOS error counter output for show interfaces or show interfaces card-type x/y counters errors for the Catalyst 6000 and 4000 Series. Show Top for CatOSThe command show top allows you to collect and analyze data for each physical port on a switch. The command displays this data for each physical port: Port utilization (Uti %) Number of in and out bytes (Bytes) Number of in and out packets (Pkts) Number of in and out broadcast packets (Bcst)  Скачать или прочитать книгу Преступление и наказание  Дорогие дети, сегодня я хочу поделиться с вами мудростью  Дорогие дети, сегодня я хочу рассказать вам о поговорке |
Warning: Category 5e and Category 6 cables can store high levels of static electricity because of the dielectric properties of the materials used in their construction. Always ground the cables (especially in new cable runs) to a suitable and safe earth ground before you connect them to the module.