The total error free packets received and transmitted on the interface. The controller senses the wire and checks if it is not busy before it transmits.Common Causes:This is normal on an half-duplex Ethernet segment. << endobj When you add the VLAN back into the VLAN table from a VTP server switch, the ports of the switches in the domain that belong to that restored VLAN become active again. This chapter includes the following major sections: Checking Module Status, page 5-1 Checking Interfaces Status, page 5-2 Checking MAC Addresses, page 5-3 << Other input-related errors can also cause the input errors count to be increased, and some datagrams can have more than one error. The frames received that are smaller than the minimum IEEE 802.3 frame size (64 bytes for Ethernet), and with a bad CRC.Common Causes:This can be caused by a duplex mismatch and physical problems, such as a bad cable, port, or NIC on the attached device.Platform Exceptions:Catalyst 4000 Series that run Cisco IOSPrevious to software Version 12.1(19)EW, a runt = undersize. If Rx-No-Pkt-Buff increments and TxPauseFrames also increments, it means that the remote end disregards the pause frames (does not support flow control) and continues to send traffic despite the pause frames. /F 27 0 R In order to resolve this issue, Cisco has developed the PortFast feature for host ports. 1 Answer Sorted by: 4 From configuration mode, type logging monitor info end then from enable mode type term [inal] mon [itor] this will send console messages to your vty session. THis is the first "up" in your "up/down" issue. 27 0 obj Once you know the switch actually has the MAC address of the device in the CAM table, determine whether this device is on the same or different VLAN from where you try to ping. Telnet sessions initiated from the switch cannot be encrypted. The Rx-No-Pkt-Buff counter can increase on ports when it has blades, such as WS-X4448-GB-RJ45, WS-X4548-GB-RJ45, and WS-X4548-GB-RJ45V. /accessLevel (Guest,Customer,Partner) << It depends on the amount of the packets that are stored in the Rx FIFO buffer of the module ASIC. This kind of source routing is only defined for Token Ring and FDDI. /Subtype /Link 5 minute input/output rate - The average input and output rate seen by the interface in the last five minutes. When you power up or down the PC, the switch port changes state, and the switch starts the TCN process. Note: To access tools and websites, you must be a registered Cisco client. Look at the "sh interface <BLAH>" and "sh controll e <BLAH>" any any line errors. The causes for this range from EtherChannel misconfiguration that causes a PAgP flap, duplex mismatch, BPDU port-guard and portfast configured at the same time, UDLD that detects a one-way link, and so on. Always use either Category 5, Category 5e, or Category 6 UTP for 10/100 or 10/100/1000Mbps connections. Common Causes:Check for a bad cable. Navigate to thelink for more information about the commands Recover Errdisable Port State on Cisco IOS Platforms: One common cause of inactive ports on switches that run Cisco IOS is when the VLAN they belong to disappears. /Type /Annot /OpenAction [6 0 R /XYZ null null null] A unidirectional link is a link where traffic goes out one way, but no traffic is received in the ingress direction. Use theshow interfaces counters errorcommand to look at OutDiscards. This total includes frames of all destination types. Typically this means frames up to 1600 bytes in size. If either device does not support Gigabit auto-negotiation, disable the Gigabit auto-negotiation, and it forces the link up. /secondaryConcept () /Kids [14 0 R 15 0 R] /Count 14 Always set both sides of the connection to auto-negotiate speed/duplex or set the speed/duplex manually on both sides. 03-01-2019 NFS file transfers that come from a Gigabit attached server that uses user datagram protocol (UDP) with a 32K window size is one example of an application setup that can bring out this type of problem. This enables the remote device to start to transmit packets. >> /Parent 5 0 R 1000BASE-T and 1000BASE-X Port Cabling Specifications, Category 5 UTP Category 5e UTP Category 6 UTP, 722 ft (220 m) 902 ft (275 m) 1640 ft (500 m) 1804 ft (550 m), 1804 ft (550 m) 1804 ft (550 m) 1804 ft (550 m) 6.2 miles (10 km). Some workstations simply cannot wait this long to find their server and then they give up. /Dest (G1030299) Unplug the cable and reinsert it. When the receive part (Rx) of the port has its Rx FIFO queue filled and reaches the high water mark, the transmit part (Tx) of the port starts to generate pause frames with an interval value mentioned in it. In order to troubleshoot auto-negotiation problems it is often recommended to try and hardcodeboth sides. The command output displays all active console port and Telnet sessions on the switch. Before you can open a Telnet session to the switch, you must first set the IP address (and in some cases the default gateway) for the switch. /Creator (FrameMaker 7.2) /Type /Annot The only way to clear the bit counters in these switches is to reload. If the source and destination belong to multiple VLANs and you specify MAC addresses, you can also specify a VLAN. Fa0/1 connected 1 a-full a-100 10/100BaseTX . An excessively loaded network can be caused by too many devices on a shared Ethernet. Check the trunking mode on each side of the link. In the example, under the show interfaces FastEthernet0/1 command, look at a line that shows something such as: Last input 00:00:41, output 00:00:00, output hang never. The traffic load on the interface is excessive and causes the frames to be discarded. << Description:show interfacescounter. The first router decrements the TTL field by 1 and sends the datagram to the next router. /Subtype /Link 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. In this case, an orange light can indicate the normal functions of the STP. The messages are generated by the switch. Refer toSpanning-Tree Protocol Enhancements using Loop Guard and BPDU Skew Detection Featuresfor more information on the loop guard feature. Try the following commands. Description:The number of times that the transmitter has been that run faster than the switch can handle.Common Causes:This can occur in a high throughput situation where an interface is hit with a high volume of traffic bursts from many other interfaces all at once. endobj FCS error count is the number of frames that were received with a bad checksum (CRC value) in the Ethernet frame. Refer to Mode-Conditioning Patch Cord Installation Note for more information. Try to find the offending device and remove it from the network. Likewise, the Last input never, output never, output hang never status means the port is not in use. The documentation set for this product strives to use bias-free language. If unicast flooding is enabled on that port, it can cause the port to shut down after a reboot. This command displays what cards are present in the switch, the version of software they are that run, and what state the modules are in: ok, faulty, and so on. traceroute [-n] [-w wait_time] [-i initial_ttl] [-m max_ttl] [-p dest_port] [-q nqueries] [-t tos] host [data_size]. The traffic load destined for this switch is excessive and causes the frames to be discarded. Failures of any test of a module or port show an 'F' in the test results. endobj 24 0 obj This is useful to know when a dead interface has failed. 6 0 obj When you operate at half-duplex setup, some data link errors incrementin Frame Check Sequence (FCS), alignment, runts, and collision counters are normal. This is an indication of a bad frame generated by the connected device. In order to check to see how long the port is in Up or Down status, use the show interfaces [interface id] command. This is because the switch does not know that the connected device is a PC; the switch only knows that the port has changed the state. % Therefore, this sum cannot balance with the sum of enumerated input error counts. This indicates that a corruption of the packet occurred within transfer, and Blackwater received the corrupted packet. If the switch overwhelms the Ethernet interface, check the speed and duplex setup. /Threads [7 0 R] For Cisco IOS on 2900/3500XL, 2950/2955, 3550, 2970 and 3750 series switches, theshow controllers Ethernet-controllercommand displays discarded frames, deferred frames, alignment errors, collisions, and so on. 10 0 obj /Dest (G1045525) Swap suspect cable with known good cable. 25 0 obj /Border [0 0 0] The number of times the receiver on the port is disabled, possibly because of buffer or processor overload. The interfaces that are "up" are in the connected state. Note: On the Catalyst 4503, 4506, and 4507R series switches, this capability is automatically enabled. The packet is then dropped. Platform Exceptions:Catalyst Cat4000 Series that run Cisco IOSPrevious to software Version 12.1(19)EW, the giants counter incremented for a frame > 1518bytes. The total number of frames which are filtered because of the type of VLAN information contained in the frame. When a port receives a Symbol, it extracts the 8 bit data from the Symbol (10 bits). /Border [0 0 0] 05-11-2020 When a host receives a datagram with an unrecognized port number, it sends an ICMP port unreachable error to the source. This is helpful to use to determine whether a misconfiguration of the mod/port or interface can cause a problem. The ports need to be in agreement as to what format they use on the link, or they do not understand each other.
The port can be configured to filter 802.1Q tagged frames. In switches that support both L3 interfaces and L2 switchport, the message"Command rejected: [interface] not a switching port"displays when you try to enter a command related to layer 2 on a port that is configured as a layer 3 interface. This issue is resolved in Cisco IOS release 12.1(19)EA1 or 12.2(18)SE or later. Note If you are using Kerberos to authenticate to the switch, you will not be able to use the secure shell encryption feature. /Author (ctsadmin-p.gen) Support for jumbo and baby giants on Catalyst switches varies by switch platform, sometimes even by modules within the switch. The SSH feature provides security for Telnet sessions to the switch. /Count 4 The traceroute command uses the Time To Live (TTL) field in the IP header to cause routers and servers to generate specific return messages. Ensure that you have the correct cable for the type of connection you want to make. This table shows an example of the commands used to configure verify and troubleshoot the errdisable status on switches. This increments when the CRC generated by theLAN station or far-end device that originates the traffic does not match the checksum calculated from the data received.Common Causes:This usually indicates noise or transmission problems on the LAN interface or the LAN itself. The designated port transmits BPDUs, and the non-designated port receives BPDUs. 7 0 obj l2trace {src-ip-addr} {dest-ip-addr} [detail]. This can happen where you have multiple high-speed ports flowing to a single (usually slower) port. /iaPath () Destination unreachableIf the default gateway cannot reach the specified network, a destination unreachable message is returned. I usually start first with the following command: Switch0# show interfaces status Port Name Status Vlan Duplex Speed Type Fa0/1 connected 1 auto auto 10/100BaseTX The reason for this occurrence is because the time to propagate the signal from one end of the network to another is longer than the time to put the entire packet on the network. These frames are dropped and not propagated onto other ports. To trace the path that packets take through the network, perform this task in privileged mode: Execute IP traceroute to trace the path packets take through the network. This traffic level constrain is due to hardware limitation. It would be counted on theshow interfaceoutput for the appropriate physical interface. If a packet is sent from any other port, in the same VLAN as port 0/2, the packet is dropped. For information about setting the IP address and default gateway, see "Configuring the Switch IP Address and Default Gateway.". /Type /Annot To open a Telnet session to another device on the network from the switch, perform this task in privileged mode: This example shows how to open a Telnet session from the switch to the remote host labsparc: The login timer is the number of minutes after which an idle session is disconnected. The CDP packets are no longer recognized, and they are dropped. The flushes counter in the show interface command output increments as part of selective packet discard (SPD), which implements a selective packet drop policy on the IP process queue of the router. output buffer failures output buffers swapped out. You can use IP ping to test connectivity to remote hosts. Use theclear counterscommand to zero the traffic and error counters so that you can see if the problem is only temporary, or if the counters continue to increment. Table20-1 lists the default values that apply to the ping-s command. These types of errors on the interface are related to a traffic problem with the ports oversubscribed. 26 0 R] This means that the port is up as far as Layer 1 (L1) is concerned. Description:show interfaces counters errors . 4 0 obj /N 59 0 R No destination unicast are the number of unicast packets that the port did not forward to any other ports. Fast aging temporarily sets the CAM aging time to the number of seconds that the user specifies, and is used in conjunction with the Topology Change Notification (TCN) process. For Cisco IOS, use theshow interfacescard-type {mod/port}trunkcommand to verify the trunking configuration and Native VLAN. The idea is that when a topology change occurs, this value is necessary to flush the CAM table faster, to compensate for the topology change. The pause packets stop when the connected device is able to receive the traffic. For more information, see the "Checking Module Status" section. /Rect [162 388.9200134277 312.299987793 400.1400146484] The Maximum Transmission Unit (MTU) of the data portion of an ethernet frame is 1500 bytes by default. The command show diagnostic was introduced in 12.1(11b)E for the Catalyst 6000 series and show diagnostics (with an s ) was introduced in for Catalyst 4000 Series. When one of the ports in a physically redundant topology no longer receives BPDUs, the STP conceives that the topology is loop free. /Length 60 0 R If you load a newer software version, it can often fix this. << Total output drops - The number of packets dropped because the output queue is full. For more information, refer to the UDLD: One-Way link problems section of this document. /Subtype /XML WK:w9\lBdOeX>V!RKB.GUMrx8<3pfs,nNX`IVw=OYGe; L2]>[1aUGYv4(}d({PJRiPh@fHK49]a9l&]+X.H bVFO4 i8qQf3 /Type /Pages the NIC cards in your machines going to sleep because of inactivity. Refer toConfiguring Jumbo/Giant Frame Support on Catalyst Switchesfor more information on system requirements, configureand troubleshootfor jumbo and baby giant issues. switch# show vtp status VTP Version : 1 Configuration Revision : 0 . An SX GBIC needs to connect with an SX GBIC. If the ratio of errors to input packets is greater than two or three percent, performance degradation can be noticed. Excessive errors for certain counters usually indicate a problem. For each group of eight ports, the frames that are received are buffered and sent to the common Gigabit Ethernet link to the internal switch fabric. >> This can happen in these situations: If a hub is connected to port 0/1, and a workstation connected to the hub transmits a packets to another workstation connected to the hub, port 0/1 does not forward this packet anywhere because the destination MAC resides on the same port. NIC Card on your devices. The source and destination switches must belong to the same VLAN. They can be defined as any frame bigger than the standard ethernet frame of 1518 bytes (which includes the L2 header and Cyclic Redundancy Check (CRC)). For further information on how to troubleshoot hardware problems on Catalyst switches that run Cisco IOS, navigate to the Cisco Switchessupport pages, choose your platform and look at the Troubleshooting > Hardwaresection. Monitorthese counters for increments as it is useful to determine whether traffic flows properly through the interface. The operating system can have a bug. The error message is received when the traffic level reaches about 2.5 Mb. For example, if a large amount of traffic bursts comes in on a gigabit interface and is switched out to a 100Mbps interface, this can cause Xmit-Err to increment on the 100Mbps interface. Alignment errors are the result of collisions at half-duplex, a duplex mismatch, bad hardware (NIC, cable, or port), or connected devices that generate frames that do not end with an octet and have a bad FCS. Bypass the media convertor if possible to rule it out. /Parent 5 0 R Late collisions can also indicate an Ethernet cable or segment that is too long. In its operation, STP relies on continuous reception or transmission of BPDUs based on the port role. /Border [0 0 0] Note: The right hand column on the next table gives a brief description of what the command does and lists any exceptions to the use per platform. The total number of frames whose length is less than 64 octets (which excludes frame bits, but includes FCS) and have a bad FCS value.
FrameMaker 7.2 Also, some packet drop incrementation is normal and is the result of traffic bursts traffic. The show interfaces card-type {slot/port}command is the used command for Cisco IOS on the Supervisor to display error counters and statistics. The command you are using is the show interfaces command. /I 31 0 R /PageLabels 8 0 R 4. /Title (Checking Port Status and Connectivity) For Cisco IOS, on modular switches like the Cat6000, use the commandshow diagnostics. /Subtype /Link The loop guard feature makes additional checks. /Filter /FlateDecode 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. This example shows you how to display the port capabilities for ports on module 2: This example shows you how to display the port capabilities for port 5 on module 3: You can access the switch CLI using Telnet. You can change the topology to route frames differently. Switches can participate as the source or destination of the traceroute command but will not appear as a hop in the traceroute command output. endobj The show interfaces status cli command shows you all interfaces. (Year 1993), 1 link ups, last link up on Mon Mar 01 1993, 00:01:37 1 link downs, last link down on Mon Mar 01 1993, 00:03:13. is the year/date not updated due to no NTP or local clock configured? Share Improve this answer Follow answered Sep 21, 2011 at 10:46 Theo 1,632 12 12 Add a comment 3 This might be a very late reply but here's what I understood so far: The interface status has two parts to it: This section lists the guidelines for the Layer 2 Traceroute utility: The Layer 2 Traceroute utility works for unicast traffic only. connect.fm For example, if a static map for MAC address X was configured on port 0/2 to forward traffic to port 0/3, the packet must be received on port 0/2 otherwise the packet is dropped. The number of times the carrier was not present in the transmission.Common Causes:Check for a bad cable. Refer to these documents for more information on the different trunking modes, guidelines, and restrictions: System Requirements to Implement Trunking. Common Causes: This error can indicate a duplex mismatch among other things. Size/max means the current number of frames in the queue/the max number of frames the queue can hold before it is full and must start to drop the frames. << Verify that each device supports 802.3z specification for Gigabit auto-negotiation. In addition, you can use Telnet from the switch to access other devices in the network. Reduce the traffic load on the interface if there are incrementsin the number of packets in this field. The Catalyst 6000/4000 does not turn the port light orange when it blocks for STP. /Rect [162 405.8999938965 319.799987793 417.1199951172] You can need to modify your network topology to reduce the traffic load for this switch. Bad NICs can also cause late collisions. In normal executive mode, the ping command supports the -s parameter, which allows you to specify the packet size and packet count. 16 0 obj The ping command is configurable from normal executive and privileged executive mode. Normally, such a condition is temporary, dependent upon transient peak loads within the system. Use theshow interfaces fastEthernet 6/1 statuscommand to display this: Last input, output - The number of hours, minutes, and seconds since the last packet was successfully received or transmitted by the interface. - last edited on (It still must be far less than one percent of the frames received.). Resolution In order to check to see how long the port is in Up or Down status, use the show interfaces [interface id] command. << In order to enable the simultaneous use of 10-Gigabit Ethernet and the Gigabit Ethernet SFP interfaces, issue thehw-module uplink select allcommand. ehxg!UD|_\\zAo*(EJu4Qa-NC-L%;1::Hr3j`39Xg35t!9 These messages generally tell you what the mismatch is and where it occurs. << New here? Collisions can cause runts, FCS, and alignment errors due to the frame notcompletely copied to the wire, which results in fragmented frames. /Type /Pages This example shows you how to display the MAC address of a specific port: This example shows you how to display the MAC addresses of all ports on a module: You can display the capabilities of any port in a switch using the show port capabilities command. Impossible to tell. For example, you can look attheMessages and Recovery Proceduresfor Cisco IOS Releases. Refer toConfiguring and Troubleshooting Ethernet 10/100/1000 MB Half/Full Duplex Auto-Negotiationfor details on how to resolve speed/duplex and auto-negotiation issues. Use theshow run interfacecommand and check to see if the interface is in ashutdownstate: If the port goes into shutdown mode immediately after a reboot of the switch, the probable cause is the port security setup. Description:show interfaces counters errors. >> Investigate these common causes of output buffer failures: Inferior Speed/Duplex for the Amount of Traffic. This is because the output buffer of the interface is overwhelmed by the excess traffic due to the speed mismatch between the inbound and outbound bandwidths. >> You can display the currently active user sessions on the switch using the show users command. Multiple splices and substandard fiber-optic cable reduce the cable distances. Description:show interfaces. HWOw6SE4[ilX}{HPV]~Pz+g f~3Qk6V-s*/|l
Km2NF%~IbQ9-t&39/Y-.L6yI*->N It is usually easier to upgrade the software than it is to upgrade hardware. >> Reduce the traffic load on the interface if you see the number of packets increase in these fields. Once you have encapsulation dot1q on a subinterface, you can no longer use that VLAN in the system because the 6500 or 7600 internally allocates the VLAN and makes that sub interface its only member. Cisco IOS error counter output forshow interfacesorshow interfaces
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