The result is the runt counter now increments inshow interfaces, along with the fragments counter inshow interfaces counters errorswhen a frame <64 bytes with a bad CRC is received.Cisco Catalyst 3750 Series SwitchesIn releases prior to Cisco IOS 12.1(19)EA1, when dot1q is used on the trunk interface on the Catalyst 3750, runts can be seen onshow interfacesoutput because valid dot1q encapsulated packets, which are 61 to 64 bytes and include the q-tag, are counted by the Catalyst 3750 as undersized frames, even though these packets are forwarded correctly. The total number of frames which experience between 2 and 15 collisions, inclusive, and are then successfully transmitted. Check or swap the copper or fiber cable. Ensure that you have the correct cable for the type of connection you want to make. If either device has multiple Gigabit ports, connect the ports to each other. Giant frames are defined as any frame over the maximum size of an ethernet frame (larger than 1518 bytes) that has a bad FCS. For example, here you see a high amount of output drops on the interface GigabitEthernet 8/9 on a Catalyst 6500 Series Switch: In order to analyze the problem, collect the output of these commands: show platform hardware capacity rewrite-engine drop. If a static address has been set up on another port in the same VLAN, and no static address was set up for the receiving port, the packet is dropped. << As an example, consider a scenario where a 1gig multicast stream is forwarded to 24 100 Mbps ports. /Subtype /Link /Count 23 If a packet was received on port 0/1, with destination MAC address X, and the switch has already learned that MAC address X resides on port 0/1, it increments the counter and discards the packet. /docType () Alignment errors are a count of the number of frames received that do not end with an even number of octets and have a bad Cyclic Redundancy Check (CRC).Common Causes:These are usually the result of a duplex mismatch or a physical problem (such as cabling, a bad port, or a bad NIC). Port Status and Configuration - Hewlett Packard Enterprise 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. The first up refers to the physical layer status of the interface. Also, some packet drop incrementation is normal and is the result of traffic bursts traffic. You have to manually re-enable the port or interface to take it out the errdisable state unless you configure an errdisable recovery option. 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 Note: For fiber connections, make sure the transmit lead of one port is connected to the receive lead of the other port. This example shows the basic usage of the traceroute command: This example shows how to perform a traceroute with six queries to each hop with packets of 1400bytes each: Catalyst 4500 Series Software Configuration Guide, 7.5, Configuring the Switch IP Address and Default Gateway, Configuring Ethernet and Fast Ethernet Switching, Configuring Fast EtherChannel and Gigabit EtherChannel, Configuring Spanning Tree PortFast, BPDU Guard, BPDU Filter, UplinkFast, BackboneFast, and Loop Guard, Configuring VLAN Trunks on Fast Ethernet and Gigabit Ethernet Ports, Configuring Dynamic VLAN Membership with VMPS, Catalyst 4500 Series, Catalyst 2948G and Catalyst 2980G Switches Software Configuration Guide, 7.5, "Configuring the Switch IP Address and Default Gateway. When a frame is received which contains an 802.1Q tag the frame is filtered and this statistic is incremented. The switch does not know that the link ingressdirection is bad (the port thinks that the link is up and works). >> If this counter increments, this is an indication that the ports are configured at half-duplex. This is useful to know when a dead interface has failed. The use of this feature can help you identify difficult to find unidirectional link problems. This only happens under stress conditions but can happen with bursts of traffic on several ports. This is an indication that the internal send (Tx) buffer is full.Common Causes:A common cause of Xmit-Err can be 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. You can need to modify your network topology to reduce the traffic load for this switch. 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. << The Catalyst4912G, 2948G, and 2980G switches are fixed-configuration switches but are logically modular. Use theinterface-rangecommand to do this on multiple interfaces at once. Use these resources to familiarize yourself with the community: Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type. The Pluggable Module provides the flexibility of adding different interfaces to the IR1101 platform, for example, a cellular module. Run a port TDR to test the integrity of the copper cable. In addition, you can use Telnet from the switch to access other devices in the network. Telnet sessions initiated from the switch cannot be encrypted. Cisco command to show all available ports - The Spiceworks Community UDLD can put a port in errdisable state when it detects a unidirectional link. Late collisions are not detected by the transmitter until after the first 64 byte slot time. Upgrade the NIC card driver to the latest version available on the web site of the manufacture to resolve this. /description () Check the cable, or other computer. If that VLAN is deleted, then the port or interface becomes inactive. Look for broken or lost pins on connectors. New here? The traffic load for this switch is excessive and causes the frames to be discarded. PDF Checking Port Status and Connectivity - Cisco This shows the last time a port sent or received traffic. Cisco Nexus 5000 Series Command Reference This command displays output similar to a Cisco router, like software image name and version information and system memory sizes. 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. Common Causes:Broadcast storms and bursts of noise can cause the ignored count to be increased. If the segment is shared, other devices on this segment can transmit so much that the switch has no opportunity to transmit. To display the MAC address for a specific port, perform this task in privileged mode: Display the MAC address for a specific port. To display the active user sessions on the switch, perform this task in privileged mode: Display the currently active user sessions on the switch. Use theshow interfaces statuscommand to display speed and duplex setup as well as other information. No destination unicast are the number of unicast packets that the port did not forward to any other ports. In order to troubleshoot auto-negotiation problems it is often recommended to try and hardcodeboth sides.