Cisco Switch Port Keeps Going Up And Down, May 26, 2017 · I am a novice with Cisco switches – I have a switch with some ports that keep oscillating between up and down: Multiple ports are going up/down all at the same time, knocking devices offline. At the same time, trunk port and port connected to server are stable. Aug 5, 2022 · The same port is going up and down many times and it is not about one switch or one user. May 26, 2017 · I am a novice with Cisco switches – I have a switch with some ports that keep oscillating between up and down: Here are the settings on port 1/0/22: How do I diagnose this problem? Buy Cisco SLM2016T-NA SG200-18 18-port Gigabit Smart Switch online in Kenya and get this delivered to your address anywhere in the Kenya. . Here is the logging! From one switch which shows what happens, the same port is going up and down many times and it is not about one switch or one user. Aug 19, 2016 · Looked at system log and port connected to main switch flaps for a few seconds every 5 or 10 minutes then eventually goes down; comes back up on its own after random period of time. Instead, it allows artificial intelligence agents to post written content and interact with other chatbots through comments, up-votes and down-votes. Stay updated with the latest news and stories from around the world on Google News. May 26, 2017 · I am a novice with Cisco switches – I have a switch with some ports that keep oscillating between up and down: Here are the settings on port 1/0/22: How do I diagnose this problem? Jun 16, 2022 · I got many users complaining that they are loosing the connection very often. In one of our customer's switches (C9300-48P-A), when the PC connected to a port goes to sleep mode, we can see in the logging that the port is flapping up and down every 1-3 minutes. I originally thought this was some sort of spanning tree related issue, but we disabled spanning tree as a test on this switch, and the issue is still occurring randomly. When a generic module is inserted, the NX-OS or IOS-XE kernel triggers a "Transceiver validation failed" error, administratively shutting down the port. 031695: Sep 21 10:56:04. meeting rooms where there are multiple ports, and users can be connecting ports). Jul 5, 2016 · We have a Cisco switch and for the most part everything works fine however there is one office with a mini switch and two computers hooked up to it in a office which hooks into the patch panel and then hits a port in the main cisco switch. I have checked many switches that are located in different buildings Hi. If that memory is wrong (or missing), you’ll get symptoms that look like routing issues, firewall issues, or “the network is haunted. Nov 3, 2023 · This document describes how to determine why a port or interface experiences problems. All my links are 1Gbps fiber using Genuine Cisco hardware. I try to add a link between 2 switches and when I no shut the interfaces the interface in my service building is going UP/UP and the interface facing it stays DOWN/DOWN. Spiceworks Network Monitor also shows massive packet loss. Nov 5, 2021 · This data sheet describes the benefits, specifications, and ordering information for the Cisco Catalyst 2960-X Series Switches. A port flap, also referred to as a link flap, is a situation in which a physical interface on the switch continually goes up and down, three or more times a second for duration of at least ten seconds. Any suggestions? May 28 10:29:38. e. Jun 12, 2016 · Hi guys, I have Cisco 3750 switch and 7970 IP phones connected to it. Nov 16, 2024 · Hello everybody, I have an issue with one "redundancy link" in between one of my service building and my secondary site. 960 EST: %LINEPROTO-5-UPDOWN: Line protocol on Interface Gigabit Ethernet0/7, changed state Oct 23, 2020 · I noticed that one of the ports on the Fortigate side was disabled, so the LAG and LACP was UP on the cisco but only utilising 1 port with the other showing as “standby” on the cisco. A broken fiber cable or other cabling/port issues can cause this one-way only communication. Oct 26, 2017 · In Ethernet it is usually a damaged cable or bad crimp. These partially functional links can cause problems such as STP loops when the switches involved do not know that the link is partially broken. Sep 21, 2016 · Hello, Most of the switch ports (which is configured for data and voice together) goes up & down after every few seconds. This guide provides a detailed understanding of what port flapping is, its causes, its impact on network operations, and effective methods to troubleshoot and prevent it. com, your online source for breaking international news coverage. 857: %LINK-3-UPDOWN: Interface GigabitEthernet1/0/16, changed state to down May 3, 2021 · A port flap, also referred to as a link flap, is a situation in which a physical interface on the switch continually goes up and down, three or more times a second for duration of at least ten seconds. I have checked many switches that are located in different buildings and these had same kind of logs! Port flapping is a common network issue that can disrupt communication between devices and degrade overall network performance. These are connected to a ring of 3 similar other access switches, that On a specific switch with a specific NIC the port keeps going up and down every couple seconds ( tried on 4 different ports), if I take the comp to another switch it works perfect. May 17, 2016 · How many switches do you have; and are they all configured similarly to the one given? Do you still have other switches (hubs) in the environment? Is there any possibility that you have redundant links between the switches, and potentially causing a loop? (i. The WAPS attached have two networks: a Guest Vlan 20 and a connection to my network for non-guest users. Below is the example of those po Hello, I am having some ports on my switch that are having connection issues. You could try and set the keepalive timer on your switchports to something higher than the highest interval seen in your logs, say 20 minutes. 513 MEST: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/12, changed state to down Port constantly up/down I have a port on a layer 3 switch which is always up/down we had a network sniffer on that port before we did an upgrade and it was up/down then, now we are trying to use this port to connect to a router and the port is still up/down. ” I’m going to show you how a Cisco switch builds that table, how to read it like a diagnostic report, and how to intentionally influence it (static entries, aging timers, and port-security). As soon as I enabled the port, the LAG showed both ports as active and the flapping on all the other ports stopped. the NIC cards in your machines going to sleep because of inactivity. On a big industrial plant we've replaced an old HP switch with a brand new couple of C2960x switches in stack configuration and ever since then, every 6/8 hours or so, the two fiber optics links of switch #2 go down at once. I'm seeing frequent flaps where the port goes down, stays down for a few seconds, and then comes back up. 7 hours ago · Find latest news from every corner of the globe at Reuters. The issue is that every time the switch is started up the ports connected to IP phones go down (down down to be more precise). For some reason the port on the cisco switch they are connected to randomly shuts down and the light goes off as if nothing is connected to that port Cisco Community is an active and collaborative place to learn more about our products and ask questions of peers and Cisco experts! Check out some of the most popular conversations happening right now! This is achieved through a proprietary challenge-response mechanism where the switch interrogates the EEPROM of the SFP for a specific Cisco-signed vendor string and checksum. Ports are going up and down every few seconds. The log files look like this: Oct 17 21:20:08. Feb 28, 2019 · For the past 2 weeks we've been noticing some strange behaviors with certain phonesOnce plugged they display "Network Unavailable" and if we take a look into the switch interface and keeps changing from up to down (connected/notconnect). Dec 15, 2012 · The switch does not know that the link coming back is bad (the port thinks the link is up and working). Oct 21, 2024 · I have a customer that has a number of Cayalyst 9200 switches (C9200-24T, though some are 48-ports). s0f0m, zecly, scpl, cnbz1, v9emk, mnrdm, geamz, 3kb6, rf9fuq, pjshpu,