endobj To display summary information on all of the ports on the switch, enter the show port command with no arguments. /Type /Annot /Annots [16 0 R 17 0 R 18 0 R 19 0 R 20 0 R 21 0 R 22 0 R 23 0 R 24 0 R 25 0 R To support authentication for Telnet with secure shell encryption, use the telnet keyword in the set authentication commands. For Cisco IOS, you can use the show interfaces command to verify whether the interface is up, line protocol is up (connected) . Port Status : Secure-down. Always check the cable for marginal damage or failure. Make congestion avoidance a priority on your network. If this counter increments, it is an indication of a wiring problem, an excessively loaded network, or a duplex mismatch. (It still must be far less than one percent of the frames received.). SeeTable 1for explanations of the error counter output. /Rect [162 439.9200134277 349.799987793 451.1400146484] Basically, up/down means the port is available for a cable/connection, but doesn't have one. For example, if a large amount of traffic flow comes in on a gigabit interface and is switched out to a 100Mbps interface, this can cause output drops to increment on the 100Mbps interface. The half-duplex side only expects packets at certain times, not at any time, and therefore counts packets received at the wrong time as collisions. ehxg!UD|_\\zAo*(EJu4Qa-NC-L%;1::Hr3j`39Xg35t!9 When one of the ports in a physically redundant topology no longer receives BPDUs, the STP conceives that the topology is loop free. 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. If the end device is on a different VLAN from where you try to ping, a L3 switch or router must be configured to allow the devices to communicate. /Dest (G1019941) CISCO MDS - Useful 'Show' Commands - DavidRing.ie 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. Description:show interfacescounter. Refer toUnderstanding and Configuring VLAN Trunk Protocol (VTP)for more information on VTP. If the switch port receives a lot of late collisions, this usually indicates a duplex mismatch problem and can place the port in an errdisable status in a result. You must enable CDP on all of the Catalyst 4000 family, Catalyst 5000 family, and Catalyst 6500 series switches in the network. endobj 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. Note: Variables that can affect routing (for example, load and reliability) are not cleared when the counters are cleared. The two options are single mode fiber (SMF) or multimode fiber (MMF). In order to check to see how long the port is in Up or Down status, use the show interfaces [interface id] command. Port or Interface Status is Disable or Shutdown Port or Interface Status is errDisable Port or Interface Status is Inactive Uplink Port or Interface Status is Inactive Deferred Counter on the Catalyst Switch Interface Increments Intermittent Failure to set timer [value] from vlan [vlan no] Trunking Mode Mismatch Jumbos, Giants, and Baby Giants stream
Cisco: All about errdisable (and how to enable ports disabled by it) how to get port/interface status of cisco switch via snmp For each Catalyst 4000 family, 5000 family, and 6500 series switch found in the path, the output shows the device type, device name, device IP address, in port name, in port speed, in port duplex mode, out port name, out port speed, and out port duplex mode. /P 6 0 R Run a port TDR to test the integrity of the copper cable. Loops can also be caused by a uni-directional link. 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. The Catalyst 6000/4000 does not turn the port light orange when it blocks for STP. /Parent 5 0 R Does the link come up? >> (Protocol down/up). You can change the topology to route frames differently. 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. To monitor inbound and outbound traffic on the port as displayed by the next output, for unicast, multicast, and broadcast traffic. Full-duplex, 100Mb/s - Full-duplex and 100Mbps is the current speed and duplex setup of the interface. Description:The number of outbound packets chosen to be discarded even though no errors have been detected.Common Causes:One possible reason to discard such a packet can be to free up buffer space. /language (en) 2 0 obj Make sure each switch can see the end device MAC address in its Content-Addressable Memory (CAM) table. Unplug the cable and reinsert it. /Dest (G1063442) << If the Rx still works on the queue, once the interval time expires, the Tx sends a new pause frame again with a new interval value. CISCO MDS - Useful 'Show' Commands CONFIG: show startup-config show running-config show running-config diff show run |include host|gateway|ntp|fcdomain|http|telnet|zoneset|vsan show start |include host|gateway|ntp|fcdomain|http|telnet|zoneset|vsan show install all status show switchname show wwn switch show switch summary show version how get the cisco switch interfaces' status by snmp? Change the software first. To change the logout timer value, perform this task in privileged mode: Change the logout timer value (a timeout value of 0 prevents idle sessions from being disconnected automatically). For troubleshoot information, see theDeferred Frames (Out-Lost or Out-Discard)section of this document. Refer to Table 1 for explanations of the error counter output. 8 0 obj Cisco recommends that you disable the unicast flooding because it also ensure that no flooding occurs on the port once the MAC address limit is reached. This can be a sign that this segment is run at an inferior speed and/or duplex, or there is too much traffic that goes through this port. The line protocol up message shows the data link layer status of the interface and says that the interface can send and receive keepalives. Gigabit Ethernet (1000 Base-X) uses 8B/10B Encoding to translate 8bit data from the MAC sublayer(layer 2) to a 10bit Symbol to send over the wire. Common Causes:Excessive collisions are typically an indication that the load on the segment needs to be split across multiple segments but can also point to a duplex mismatch with the attached device. >> /Parent 14 0 R /Dests 10 0 R Switch Port View - Cisco Meraki If the source and destination belong to multiple VLANs and you specify MAC addresses, you can also specify a VLAN. This does not tell you whether autoneg was used to achieve this. Note: If the Deferred Counter error increments on a GigabitEthernet of a Supervisor 720, turn on speed negotiation on the interface as a workaround. /Border [0 0 0] Bypass the patch panel if possible to rule it out. If the link light for the port does not come on, you can consider these possibilities: Connect cable from switch to a known good device. 01:05 AM. The command output displays all active console port and Telnet sessions on the switch. A dribble bit error indicates that a frame is slightly too long.Common Causes:This frame error counter is incremented for informational purposes, since the switch accepts the frame. Verify the cable selection. This is useful to know when a dead interface has failed. The software version is also a factor. 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. endobj This will give you the last upinformation. Also, if there is a hub connected to the port, collisions between other devices on the hub can cause these errors.Platform Exceptions:Alignment errors are not counted on the Catalyst 4000 Series Supervisor I (WS-X4012) or Supervisor II (WS-X4013). Use theshow mac address-table dynamiccommand or substitute theinterfacekeyword. 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. >> switch# show port-channel summary Flags: D - Down P - Up in port-channel (members) I - Individual H - Hot-standby (LACP only) . This happens when new hardware comes out and requires special support from the software. Eventually, the block port from the alternate or backup port becomes designated and moves to a forwarding state. Cisco command to show all available ports - The Spiceworks Community Note For complete syntax and usage information for the commands used in this chapter, refer to the Command ReferenceCatalyst4000Family, Catalyst 2948G, and Catalyst 2980G Switches. Cisco IOS error counter output forshow interfacesorshow interfaces counters errorsfor the Catalyst 6000 and 4000 Series. After 12.1(19)EW, a giant inshow interfacesincrements only when a frame is received >1518bytes with a bad FCS. New here? 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. 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. Description:show interfacesandshow interfaces counters errors. Bad Port or Module Port or Interface or Module not enabled. 06-22-2009 << The messages are generated by the switch. Output queue - The number of packets in the output queue. The two devices that cause the late collision never see that each sends until after it puts the entire packet on the network. >> Check the cable, or other computer. In many cases, this is the result of a bad NIC. /Dest (G1060208) Description:show interfaces counters errors. The Catalyst enterprise LAN switches are multimodule systems. No action is required. /country (US) Just issue the 'show interface fx' command and look under 'Last input/Last output. Interface up/down: why? - Cisco The 300msec default debounce timer comes from the firmware polling timer to the linecards, which occurs every 300 msec. endobj On a Catalyst 4510R series switch, in order to enable both the 10-Gigabit Ethernet and the Gigabit Ethernet SFP uplink ports, there is an optional configuration. endobj You can use IP traceroute to identify the path that packets take through the network on a hop-by-hop basis. If collisions increase dramatically, this points to a highly utilized link or possibly a duplex mismatch with the attached device. An advantage of PortFast is that this feature suppresses TCNs for a host port. In order to convert the interface from layer 3 mode to layer 2 mode, issue the interface configuration commandswitchport. Each time we previously disconnected and reconnected the cable the port status just remained down/down. (The flushes counter can be used but never increments on the Catalyst 4000 Series that run Cisco IOS.) The number of failed buffers and the number of buffers swapped out.Common Causes:A port buffers the packets to the Tx buffer when the rate of traffic switched to the port is high and it cannot handle the amount of traffic. 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. /P 6 0 R If you turn the trunking mode to on (as opposed to auto or desirable) for one port and the other port has the trunking mode set to off, they are not able to communicate. In addition, these packets are not reported in the appropriate category (unicast, multicast, or broadcast) in receive statistics. /docType () 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)). There are no specific requirements for this document. This is an indication of a bad frame generated by the connected device. Note: For 2900/3500XL Series switches use theshow interfacescard-type {slot/port}command with theshow controllers Ethernet-controllercommand. Switch#show port-security interface fastEthernet 0/1 Port Security : Disabled. >> /Type /Annot Use theshow interfacecommand for Cisco IOS to look for errdisable, disable or shutdown status. >> Common Causes:This is typically a physical issue (such as cabling, a bad port, or a bad Network Interface Card (NIC)) but can also indicate a duplex mismatch. /Type /Metadata To determine when a datagram reaches its destination, traceroute sets the UDP destination port in the datagram to a very large value that the destination host is unlikely to be using. Command to see Switchport Uptime - Cisco Community Excessive errors for certain counters usually indicate a problem. 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 /Dest (G1024221) 20 0 obj the NIC cards in your machines going to sleep because of inactivity. These are brief descriptions of when the No dest, (unicast, multicast, and broadcast) counters can increment: If a port is an access port, and the port is connected to an Inter-Switch Link Protocol (ISL) trunk port, the No dest counter is very large since all inbound ISL packets are not forwarded. 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. See theCommon Port and Interface Problemssection of this document for more information. 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. Reconfigure the trunk encapsulation on both devices. Information is displayed about all Catalyst 4000 family, Catalyst 5000 family, and Catalyst 6500 series switches that are in the path from the source to the destination. The maximum number of hops an l2trace query will try is 10; this includes hops involved in source tracing. The Cisco Catalyst IR1101 Rugged Series Router is a next generation modular industrial router which has a base module with additional Pluggable Modules that can be added. 29 0 obj Ifshow interfacesshows up/ line protocol up (connected) but you see errors increment in the output of either command, refer to the Common Port and Interface Problems section of this document for advice. This high load of traffic oversubscribes the ports, which exhausts the input buffers and causes the Rx-No-Pkt-Buff counter and input errors to increase rapidly. If this does not solve the issue, you need to consider a module without any oversubscription of ports. This issue is resolved in Cisco IOS release 12.1(19)EA1 or 12.2(18)SE or later. Normally you can identify this situation if the port has many packet errors, or the port constantly flaps (loses and regains link). This example shows how to disconnect an active console port session and an active Telnet session: The next two sections describe how to use IP ping. %PDF-1.4 This command displays output similar to a Cisco router, like software image name and version information and system memory sizes. This chapter consists of these major sections: Using Secure Shell Encryption for Telnet Sessions. /Rect [162 337.9200134277 311.1000061035 349.1400146484] Ping will return one of the following responses: Normal responseThe normal response (hostname is alive) occurs in 1 to 10 seconds, depending on network traffic. If stations are not able to talk to their primary servers when they connectthrough the switch, the problem can involve delays on the switch port when it tries to becomeactive after the physical layer link comes up. If the frames received on any group exceeds the bandwidth of 1 Gbps, the device starts to drop the frames. endobj /Count 4 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 This command displays the current configuration file of the switch. /Dest (G1030299) 26 0 R] Port status as seen in the color assist mode. Late collisions are not detected by the transmitter until after the first 64 byte slot time. >> Other possible causes of data link errors at full-duplex are bad cables, faulty switch ports, or NIC software/hardware issues. The example shows the log messages that result from a duplex mismatch between two Catalyst 6000 series switches: one that runs CatOS, and the other that runs Cisco IOS. THis is the first "up" in your "up/down" issue. 27 0 obj This counter indicates the internal state of the Switching ASICs on the Supervisor and does not necessarily indicate an error condition. Runt frames or frames received that are less than 64 bytes (which includes the FCS bits and excludes the frame header) and have either an FCS error or an alignment error. A switch is in down state when there is nothing connected to the port or if its admin shutdown. Descriptions:show interfacescounter. FCS 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. Jumbos have larger frame sizes, typically > 9000 bytes. If you load a newer software version, it can often fix this. Swap suspect cable with known good cable. The command output displays all network layer (Layer3) devices, such as routers, that the traffic passes through on the way to the destination. The size of this buffer is only 16 KB. 22 0 obj This is helpful to use to determine whether a misconfiguration of the mod/port or interface can cause a problem. Refer toCisco Technical Tips Conventionsfor more information on document conventions. This is the command to use on the Catalyst 6000, 4000, 3550, 2950, and and 3750 series. Release Notes for the Cisco Catalyst IR1101 Rugged Series Router These are the total number of packets received that were less than 64 octets long (which excludes frame bits but includes FCS) and have a good FCS value. Checking Port Status and Connectivity Download this chapter Checking Port Status and Connectivity Download the complete book Catalyst 4500 Series, Catalyst 2948G and Catalyst 2980G Switches Software Configuration Guide, 7.5 ( PDF - 6 MB) Feedback Table Of Contents Checking Port Status and Connectivity Checking Module Status Checking Port Status The | include connected shows only the lines of the output that contain the word "connected". UDLD can put a port in errdisable state when it detects a unidirectional link. /Last 44 0 R When you operate at half-duplex setup, some data link errors incrementin Frame Check Sequence (FCS), alignment, runts, and collision counters are normal. Five hundred and twelve bit-times corresponds to 51.2 microseconds on a 10 Mbit/s system. endobj ), how to connect the different cables, and which cables are used by most Cisco switches and modules, refer to Catalyst Switch Cable Guide . cisco - interface down time summary - Network Engineering Stack Exchange The Canonical Format Indicator (CFI) bit in the TCI of an 802.1q frame is is set to 0 for the ethernet canonical frame format. 03-25-2019 The number of times the receiver on the port is disabled, possibly because of buffer or processor overload. Refer to theCatalyst Switch Cable Guide. In order to see POST results per module, use theshow diagnostics modulecommand. Cisco Internetwork Operating System Software . /Type /Pages These frames are dropped and not propagated onto other ports. PDF Checking Port Status and Connectivity - Cisco In order to overcome this situation, manually configure the speed and duplex, as well as disable the flow control, if required. The rcv-err counter on a 5K only increments as a result of excessive traffic. In some cases, these delays can be up to 50 seconds. 5 0 obj If you have device A connected to device B over a Gigabit link, and the link does not come up, perform this procedure. Collisions must not be seen on interfaces configured as full duplex. The total number of frames whose transmission attempt is abandoned due to insufficient resources. Wheb ports or interlaces are shut down as a result of errdisable are referred to as causes in Cisco IOS. /Border [0 0 0] NIC Card on your devices. Specify a particular module number to see information on the ports on that module only. If Rx-No-Pkt-Buff is zero or does not increment and the TxPauseFrames counter increments, it indicates that our switch generates pause frames and the remote end obeys, hence Rx FIFO queue depletes. A common cause is traffic from a high bandwidth link that is switched to a lower bandwidth link or traffic from multiple inbound links that are switched to a single outbound link. 5 Checking Port Status and Connectivity 5Checking Port Status and Connectivity This chapter describes how to check switch port status and connectivity on the Catalyst 4500 series switch. The STP loop guard feature provides additional protection against Layer 2 forwarding loops (STP loops). Reduce the switch load if thenumber of packets in this field increase. 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. Up to eight simultaneous Telnet sessions are possible. << /Subtype /Link Description:show interfacescounter. 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). Cisco IOS has the option to use theglobal spanning-tree portfast defaultcommand to automatically apply portfast to any interface configured as a layer 2 access switchport. Hi Nima, "show ip interface" command would show you the L1 and L2 status of the interface, instead "show port-security interface" would show you the status of the port security, now if you enable port security on an interface where there is a host connected the port status would be in "Secure-up", but if there is nothing connected to that interface, then the port status would be "Secure-down . 18 0 obj 5 minute input/output rate - The average input and output rate seen by the interface in the last five minutes. Layer 1 goes down and then up. Telnet sessions initiated from the switch cannot be encrypted. For example, you have a switch that has two Gigabit ports. This is useful to know when a dead interface failed. In this case, an orange light can indicate the normal functions of the STP. Here, the VLAN aging time is already set to fast aging. . If single connection or Step 3 fails with SC connectors, loop the port back to itself (port one RX goes to port one TX). /Subtype /Link This example shows the source and destination MAC addresses specified, with no VLAN specified but with the detail option specified. Refer toTroubleshooting Cisco Catalyst Switches to NIC Compatibility Issuesfor details on how to resolve third-party NIC issues. endstream /Rect [162 490.9200134277 306.8999938965 502.1400146484] The designated port transmits BPDUs, and the non-designated port receives BPDUs. /MediaBox [0 0 612 792] Note: There can be differences in the implementation of the counters across various platforms and releases. Undersize = frame < 64bytes. /Type /Annot In order to troubleshoot auto-negotiation problems it is often recommended to try and hardcodeboth sides. For Cisco IOS, on modular switches like the Cat6000, use the commandshow diagnostics. Look at the "sh interface " and "sh controll e " any any line errors. endobj An excessively loaded network can be caused by too many devices on a shared Ethernet. I am not sure if there is a command that show that, however if you have monitoring system it will show when and how many times has an interface gone up and down. If a port just acquired a link, there is a very brief (less than one second) period where inbound packets are not forwarded. Make sure your L3 addressing on the end device and on the router/ L3 switch is correctly configured. If 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 default CAM aging time is five minutes, which means that the switch flushes the table of learned MAC addresses every five minutes. 13 0 obj /Border [0 0 0] Every port on a Layer 3 switch configured to be a L2 switchport must also belong to a VLAN. 24 0 obj The bytes counter includes both the data and MAC encapsulation in the error free packets received and transmitted by the system. When the cable is first connected to the port, some of these errors can occur. In order to avoid packet drops on the device connected to the catalyst switch, issue theip cefcommand on the fast Ethernet interface of the device connected to the switch. Collisions can cause runts, FCS, and alignment errors due to the frame notcompletely copied to the wire, which results in fragmented frames. 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. In normal executive mode, the ping command supports the -s parameter, which allows you to specify the packet size and packet count. Switches can participate as the source or destination of the traceroute command but will not appear as a hop in the traceroute command output. Check the trunking mode on each side of the link. Because of this, a chance exists for the device connected to the catalyst switch to drop packets. Network or host unreachableIf there is no entry in the route table for the host or network, a network or host unreachable message is returned. The runt counter only incremented when a frame less than 64 bytes was received. Description:The number of times the receiver hardware was unable to hand received data to a hardware buffer.Common Cause:The input rate of traffic exceeded the ability of the receiver to handle the data. You can also use thespanning-tree portfastcommand per interface, but this requires that you turn off trunking and etherchannel separately to help fix workstation startup delays. This only happens under stress conditions but can happen with bursts of traffic on several ports. The total number of frames whose first transmission attempt was delayed, due to traffic on the network media. Note If you are using Kerberos to authenticate to the switch, you will not be able to use the secure shell encryption feature. The SSH feature provides security for Telnet sessions to the switch. A fragment is a frame < 64 bytes but with a bad CRC. If neither auto-negotiation or hardcode setupseem to work, there can be a problem with the firmware or software on your NIC card. Common Causes:Broadcast storms and bursts of noise can cause the ignored count to be increased. Problems have been seen when you connect to devices manufactured before the IEEE 802.3z standard was ratified. >> Text WK:w9\lBdOeX>V!RKB.GUMrx8<3pfs,nNX`IVw=OYGe; L2]>[1aUGYv4(}d({PJRiPh@fHK49]a9l&]+X.H bVFO4 i8qQf3 endobj setup auto speed/duplex on one side and 100/Full-duplex on the other side is also a misconfiguration and can result in a duplex mismatch. The table describes the LED status indicators for Ethernet modules or fixed-configuration switches: Ensure that both sides have a link. Someone else in the community shared this with me quite awhile back. The traffic load destined for this switch is excessive and causes the frames to be discarded. When you operate at full-duplex, errors in FCS, Cyclic Redundancy Checks (CRC), alignment, and runt counters must be minimal. Make sure the port or module has not been disabled or powered down for some reason. /Type /Annot 7 0 obj i see. /Dest (G1020140) Try to find the offending device and remove it from the network. << For more information on troubleshoot hardware related errors on Catalyst switches, see the Hardware Problems section of this document.
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