Juniper switch port flapping When I need to connect a new computer to the Ethernet port or when I plug in an unmanaged switch into the network jack in the wall so that I can connect more than one computer using the Ethernet port to the switch I will type in the following two commands within the Juniper switch's command-line interface (Junos OS CLI). 202 and ae0. Command to Disable an Interface/Juniper No Shutdown Interface. Firewall filters define the rules that determine whether to forward or deny packets at specific processing points in the packet flow. Click “upgrade switches“ → “Upgrade switch firmware” → Select the firmware of choice. Set a port to operate as a Virtual Chassis port (VCP), or delete the VCP setting on a port. Users with SuperUser or Network Admin privledges for the site can upgrade Junos on one or more switches by selecting the switches from the list and clicking the Upgrade Firmware button that appears. Learn about the key features and benefits, models and specifications, and FRUs and extension modules of EX4400 switches. Starting with Junos OS Release 14. If the port flapping does not occur, then the issue is due to internal configurations and issues in the flapping switch port. Oct 25, 2023 · Interface/Port down. The configuration of this switch was double checked and everything is ok. Customer reported port-0/3/0 issues. Port: vcp-255/1/0. EX4400 System Overview | Juniper Networks X Hi Team, I am looking for some help here . Aug 16, 2012 · KB73617 : Juniper Port Naming Convention on JUNOS KB35907 : [MX5] CLI command 'show interfaces terse' displays unsupported port status of xe-0/0/* KB74775 : MX304: After the router boot-up, the "tunnel-oamd" subsystem may not start. the goes down again. Many network devices send a gratuitous ARP packet when switching an IP address from one device to another. Solution. in the meantime I discovered, that setting one member-port of the VLAN to loopback like suggested above was a very bad idea: The mac addresses from PCs connected to other VLAN member port start flapping between their connected port and the port set to loopback. The switch has no access ports, all ports are trunks. Another frustrating and functionality-impacting problem is that of a port (or ports) stuck in the “down” state. Remember that ge-0/0/0 and ge-0/0/2 are currently part of a security-zone; you will need to include ae0. whenever these messages are coming, people connected with ex-2200 switches experiences intermittent connectivity loss to their mail, communicator. In case of loop in a VLAN, our Cisco isses a MAC FLAPPING warning (SW_MATM-4-MACFLAP_NOTIF). You need to understand the concept of mac learning and how a table is maintained on a switch, when the switch receives a frame, and associates the MAC address of the sender with the LAN port where it was received. When troubleshooting a virtual chassis adjacency problem, you should always check the vc-port statistics to make sure this is not a Cyclic redundancy check (CRC) or framing errors issue on the virtual chassis port. To verify an Aggregated Ethernet Interface (LAG) or an IRB interface (called VLAN interface in legacy platforms), refer to KB22217 - Resolution Guides - EX - Troubleshoot/Verify Interface . You can then disable the port or disconnect it. I also see on my non-flapping Cisco switch that the SRX is not seen as an EDGE port which is what I would have thought it would have appeared as. Seems like that first the switch port goes down and then the client follows because in the affected devices we have different desktops, laptops and even printers, also as i've already said most of the times in the Windows Event Viewer i don't see any event related to this. Packet drops . This topic applies only to the J-Web Application package. Example of continuous messages: [node_name: mgmt_port_link_status_poll: netif. fpc0:----- RX TX . To disable the flapping port on your switch, select your desired item with the check box and the Disable Port button will appear. Ask questions and share experiences about EX and QFX portfolios and all switching solutions across your data center, campus, and branch locations. You (the network administrator) can configure damping to reduce the advertisement of physical interface transitions between up and down states. However, these ports are continuously flapping which is causing disturbance for other devices (ex: Access points) to reboot. Hello, we are replacing an Cisco swith with EX4200 / EX3200. Jun 25, 2019 · Issue Description Network interfaces are flapping Frequent log messages similar to the following in /var/log/ltm: info bcm56xxd[7553]: 012c0015:6: Link: is DOWN info bcm56xxd[7553]: 012c0015:6: Link: is UP Environment Network interface Cause Network interface flapping is typically caused by one of the following: Speed or duplex mismatch Faulty cable Faulty SFP Faulty interface Recommended Mar 25, 2025 · RJ-45 Management Port Connector Pinout Information | 85 Console Port Connector Pinout Information | 86 RJ-45 to DB-9 Serial Port Adapter Pinout Information | 87 RJ-45 Port, SFP Port, SFP+ Port, QSFP+ Port, and QSFP28 Port Connector Pinout Information | 88. To perform Layer 1 troubleshooting, physical access of the switch is required, please arrange an tech who can access the switch to perform below steps. From there you can calculate the last flapped time with respect to the system uptime then weed out the ports you don’t want. show interface fe-x/x/x detail (flap status in interface) 2. Sep 12, 2023 · 2. Jan 3, 2011 · Description. . If the alarm is still there then, with all the connections removed from the failed switch, power cycle/Hard reboot the problem switch. (try that on both ends) looping the port to a known good port (such as port 1 connected to port 2) using a short cable can also be used to confirm if the link issue is due to local port or remote port. Disabled - Does not participate in STP, the switch port is administratively disabled. In this topic we have information related to the port speed on a ACX routers and line cards, support for multiple port speed details, Use the procedures described in this topic to set up Virtual Chassis ports (VCPs) to connect two switches together in an EX Series or a QFX Series Virtual Chassis. If you have diagnosed the issue to be in the port, try swapping the switch port with a different switch port to check if port flapping still occurs. 54:4b:8c:47:84:00 Root cost : 20000 Root port : ge-0/0/1 Hello time : 2 seconds Maximum age : 20 seconds Forward delay : 15 seconds Message age : 1 Number of topology changes : 27 Time since Mar 30, 2022 · Port flapping may be caused by unreliable connections, continuous rebooting of a device connected to the port, incorrect duplex configurations, and more. Eventually it brought the link down and we had to manually reboot the stack and clear an err'ed port on the upstream switch. As you can see I have ports flapping quite often. but after 5 minutes, they will This checklist provides links to troubleshooting basics, an example network, and includes a summary of the commands you might use to diagnose problems with the router and network. Feb 11, 2008 · State, the switch learns MAC addresses sent on this switch port. b. Hi Folks, Please anable bgp traceoptions in both mx and srx end; share the same after the next flap, To trace BGP protocol traffic, include the traceoptions statement at the [edit protocols bgp] hierarchy level. More on this later today. 0 with flags: 0x2101f Aug 5, 2023 · root@Juniper> show system uptime fpc0: KB71480 : [Junos] Layer 1 troubleshooting - Physical interface down/flapping. Jan 20, 2012 · Identify the interface that is constantly flapping. Does this just mean the device (computer) that is attached to this port is being turned off or on? Jan 25, 2012 · This article explains how to identify an interface which has changed state on an EX series switch. To identify an interface that has flapped, perform the following steps: Run the following command to verify if the interface has flapped: show interfaces <interface-name> Example: Oct 25, 2023 · This troubleshooting guide can be used to resolve the issue if following symptoms are reported on a Juniper device. 202 P2p . Juniper Networks Port Checker provides a visual representation of various Juniper network devices, and assists to configure and validate different port combinations. Dec 18, 2024 · Port or multiple ports does not come up after upgrade on QFX switch Solution In case when port stays down after an upgrade, please follow below steps to resolve the issue and collect outputs to root cause the issue. I checked with ISP support and on their end, the port is up, both administratively and operationally. Dec 27, 2023 · We're experiencing intermittent flapping of 10G Base-T interfaces on our QFX5120-48T-6C switches deployed in a virtual chassis configuration. I have configured LACP on the switch and set the vDS Port Group to Route Based on IP Hash (802. I have configured a regular SFP port on the juniper and added it to the port channel group and plugged that in to the X2 port with the fs. To maintain that consistency, Junos OS Limit the number of advertisements of the up and down transitions (flapping) on an interface. If flapping happens at short intervals, it can cause a spike in the CPU utilization as well. It corresponds to FPC-0, PIC-3, port-0. Check host reachability and network connectivity. It will cause instability in the network by compromising the redundancy of VCP links and it may also cause traffic drops in the network. Virtual chassis flapping | CRC errors on VC Port | VC adjacency lost . Printable View « Go BackGo Back As soon as the switch detects the MAC address on the new interface, it immediately updates the table. 3ad), my config looks as follows - port-channel load-balance src-dst-ip interface Port-ch Static address resolution protocol (ARP) table entries are reponded to by default when the destination address of the ARP is on the local network. This article explains how to verify that the Physical Interface of an EX switch is UP, and to troubleshoot it if it is not. Hopefully, I'll be able to find exactly how this was created to duplicate it in lab. The MLAG will also need an inter-switch-link between the two core switches (HP uses the 'switch-interconnect' command to establish those). we are running pvstp+ on this cisco box. Clicking on this will bring up a Disable Port modal that lists When I plug in the breakout cable from the juniper to the Cisco using the fs. This might lead to latency in the network and other network problems. MAC limiting protects against flooding of the Ethernet switching table, and is enabled on Layer 2 interfaces (ports). Below is the output of show log messages on one of my switch stacks. Below is the output of show log messages on one of my switch stacks. show bgp neighbor (flap status in bgp) if interface flap does bgp also will show flapping? does is down the services? Jan 20, 2012 · root@Switch> show spanning-tree bridge detail STP bridge parameters Routing instance name : GLOBAL Context ID : 0 Enabled protocol : RSTP Root ID : 4096. 3 on an EX4300 (what I am using - not sure about your switch). Dec 25, 2023 · Under loop condition, it can happen that the same MAC is learned via two different ports on the switch. Sep 16, 2019 · Hi All, One of my customer is facing issue with port flapping on the Switch when I checked the Switch logs its saying due to STP (The Port is Blocked by STP) after 2 seconds the ports come up and the issue reoccurs after 30 mins. Apr 7, 2008 · Description. Interface/Port down. The below topics discuss the overview aggregated ethernet interfaces, configuration details of link aggregation and aggregated Ethernet interfaces, troubleshooting and verification of aggregated Ethernet Interfaces. 0 root@Juniper# run show interfaces ge-0/0/1. 2, packets that need to be forwarded to the adjacent network element or a neighboring device along a routing path might be dropped by a device owing to several factors. I am keep getting below mentioned messages on ex-2200 switch that shows LACPD changes. [node_name: vifmgr: vifmgr. Does this just mean the device (computer) that is attached to this port is being turned off or on? If not, then how do I troubleshoot flapping ports? Mar 23, 2017 · While removing the connections from switch one by one, check if the alarm raised disappears at some point on problem switch or moved to the newer switch. Upgrade Junos OS Software on Your Switch | Mist | Juniper Networks Apr 26, 2002 · Display status information and statistics about interfaces on SRX Series appliance running Junos OS. Log message: Thu Dec 14 03:01:37 2023 vlan_name vlan_802+802 mac aa:aa:aa:aa:aa:aa was moved from ge-0/0/70. Damping helps reduce the number of these advertisements. Setting an Uplink Port on an EX Series or QFX Series Switch as a Virtual Chassis Port | Junos OS | Juniper Networks Problem: We have a lot of Mac Flap on Catalyst vlans, when flaps occur nexus and juniper are affected (mac move are present in logs) and we can see disconnections and issue everywhere. 5 days ago · This can be useful for maintenance or if the interface is not currently needed. This document describes how to troubleshoot when there is mac move on a Juniper switch and how to prevent it. Note down the end device and port triggered the alarm. KB35389 : [QFX5100] Continuous link flap seen This topic discusses various troubleshooting scenarios. Similar functionality we use on Edge-Core switches, this is called Sticky MAC and prevents re-learning MAC on the wrong port. This causes heavy connection interruptions of those PCs. If it's on the Uplinks, configure STP, If it's on the client side, there could be many many issues. Apparently no config is required on the switch, but the feature was only implemented in 17. This is where the RADIUS server sends a COA (Change of Authorization) message to the switch that changes the VLAN and also bounces the port to force a new DHCP request. iv. After setting a port as a VCP, you can’t use the port for any other purpose unless you remove the VCP setting. Learn about flow control for Ethernet interfaces, how to enable and disable flow control for Ethernet interfaces. 57. e. These static ARP addresses can be configured for Ethernet or Gigabit Ethernet interfaces. The last things I have to do is to sniff the traffic between the switch and the Juniper to undersantand a) if the switch drop some OSPF hello packet or b) if the Juniper is not able to process them Nov 1, 2023 · Multiple data ports flapping in both nodes of the HA pair. 44 Tbps of Layer 2 and Layer 3 connectivity to networked devices such as secure routers, servers, and other switches. one of my ex-2200 switch is connected with ex-4200 switch with aggregated etherenet . Solution Nothing special is configured on the port, it is running at 10G speed, show interfaces diagnostics optics shows that it's getting light (approx -4 dBm), but the port stays down. Keeping network security in mind, we recommend to create a restricted network profile, which will be assigned to unknown devices when connected to the switch ports that are enabled with DPC. Aug 24, 2021 · Problem is being traced back to a single switch port on which a faulty device may have been connected. VC-port flapping; Or any issues which are caused due to issue at the physical layer/interface level. Nov 20, 2023 · During VCP port flapping issue, we will notice interface flaps and carrier transaction counter increase happening. The ping command sends Internet Control Message Protocol (ICMP) ECHO_REQUEST messages to elicit ICMP ECHO_RESPONSE messages from the specified host. VC port down; Interface flapping. Could be a L2 loops but we cant find the root cause, Mac that are Flapping are from different vlans and dislocated on different switch. Total octets: 485051116209 2530448696063 Jul 19, 2023 · Port Stuck. Featuring up to 72 wire-speed 10GbE small form-factor pluggable and pluggable plus transceiver (SFP/SFP+) ports, and up to 12 wire-speed 40GbE quad SFP+ transceiver (QSFP+) ports in a compact one rack unit (1 U) platform, the Juniper Networks ® EX4600 Ethernet Switch delivers 1. Release Note: RSTP might process BPDUs, which do not comply with the IEEE standard; this might lead to unintended spanning-tree convergence behavior. You can verify the number of interface flaps with: root@Switch> show interfaces <interface-name> extensive | match "Carrier transitions" I ended up scripting it to run an snmp query on the uptime of interfaces and their admin / oper status along with the system’s uptime. Learn how to effectively perform loopback testing for Fast and Gigabit Ethernet interfaces. Feb 25, 2023 · On all Junos and Junos OS Evolved platforms, if CCC (Circuit Cross-Connect) is configured to use a label-switched-path such as IGP routed, i. Read this topic to understand how you can troubleshoot issues that cause an access point (AP) to disconnect from the cloud. Feb 11, 2025 · Best Practice to set up a Dynamic Port Configuration. This issue affects multiple servers (approximately 10) equipped with 10G interfaces bonded in LACP for redundancy. To verify port state Mar 14, 2022 · In the above example, the switch's current time is verified. 0 disable << This is cisco equivalent of “no shutdown” Verification root@Juniper#show ge-0/0/1. root@Juniper# delete interfaces ge-0/0/1. Previously they may have been working fine and showing as “up” correctly, but for some reason, they are now stuck in a down state even with some layer 1 connectivity and signalling still occurring on the remote end. Is there a quicker way to do this? Cheers, James 5 days ago · Interfaces User Guide for Switches - Juniper Networks Software\) [EX] How to identify an interface that has flapped. The below topics discuss the troubleshooting of network interfaces and diagnosing a faulty twisted-pair cable. Jumbo frames are Ethernet frames with more than 1,500 bytes of payload (Maximum Transmission Unit, MTU). ARP and MAC address tables normally stay synchronized in MC-LAG configurations, but might get out of sync under certain network conditions (such as link flapping). Enabling/disabling ports flapping issue: “Two (ex-4100 12-p) are connected to each other via multi-gig interface configured as trunk link. See Virtual Chassis Port Options for details on which ports you can set as VCPs on different switches. For routing instances, include the traceoptions statement at the [edit routing-instances routing-in There is a switch (Extreme Networks) betweend the Juniper and the Cisco. Interface does not come up. For some reason my Cisco switch with the flapping goes to : Gi4/10 Desg BLK 4 128. just wanna checkwhat does flap means and what is the different of flap and what causes of flapping (physical, power failure/reboot,???) 1. Hi, I am using Ex-3200 switch at one end and Ex-4200 , i have configured Layer 3 LACP protocol etherchannel on both EX switches with following configurations SW This topic describes the following troubleshooting issues for a Virtual Chassis: Mar 23, 2017 · While removing the connections from switch one by one, check if the alarm raised disappears at some point on problem switch or moved to the newer switch. To minimize the impact in such scenarios, Arista introduced the 'link-debounce Apr 6, 2023 · I ran into a similar issue on a stack of 4400's. With LACP, the sender decides which of the two links will carry the traffic, usually on the basis of a hash of mac addresses, ip addresses and port numbers. linkDown:info]: Ethernet e0c: Link down, check cable. This example shows how to configure and apply firewall filters to control traffic that is entering or exiting a port on the switch, a VLAN on the network, and a Layer 3 interface on the switch. Network traffic disruption . Why does my ae0 link (LACP) go down when a layer-3 device gets an IP Address only when that device is connected to any (ToR Switch) access port (rstp edge). To ensure these tables remain in sync while those conditions are being resolved, we recommend enabling the arp-l2-validate statement on IRB interfaces in an MC-LAG configuration. 58 EX4000 switches run Junos OS, Juniper’s powerful and robust network operating system that powers all Juniper switches, routers, and firewalls. Symptoms. 0 terse Switch(config)# errdisable detect cause link-flap 現場で必要な「スイッチ」の基礎知識 EthernetFablic(L2 Fabric)で、ループフリーのマルチパス構成 Disable rather than block an interface when enforcing MAC limiting, MAC move limiting, and rate-limiting configuration options for shutting down the interface, and With above configuration you just need to make sure that your switch also has a L2 port-channel created acting as a trunk port and passing the vlan-ids created on the sun-units (202 and 205). 3. Sep 21, 2023 · To check for CRC alignment errors you can issue the command "show virtual-chassis vc-port statistics extensive", and you will see an output like this one: root@switch> show virtual-chassis vc-port statistics extensive . And after a minute or two the device has been turned off and back on again. com X2 on the Cisco Jun 3, 2024 · This article explains how to troubleshoot the port and optics when the port shows down on the show cli commands. 0 to ae5. Each time a transition occurs, the interface state is changed, which generates an advertisement to the upper-level routing protocols. Physical interface: xe-0/3/0, Enabled, Physical link is Down Last flapped : 2024-05-08 01:14:10 UTC (2d 07:21 ago) Solution Switch port. The Port Status monitor provides summary and detailed information about the status of the physical network interfaces for the selected node in the View pane. MAC move limiting detects MAC movement and MAC spoofing on access interfaces. To troubleshoot a firewall, use the Junos OS command-line interface (CLI) and LEDs on the chassis: I would first set updown messages to go to a specific file on the box like this: [edit system syslog] file interface-logs { any any; match UpDown; By default, the switch floods these unicast packets that traverse a VLAN to all interfaces that are members of that VLAN. QFX10002 DC Power Cable Specifications. Forwarding - transmits and receives frames. Forwarding this type of traffic can create unnecessary traffic that leads to poor network performance or even a complete loss of network service. Oct 31, 2011 · Synopsis: The root bridge is flapping between Juniper EX and Cisco; even though EX8200 is configured for RSTP and Cisco is configured for PVST. QFX10002 DC Power Specifications. How can I tell if this is a layer-3 issue or a layer-2 issue? You (the network administrator) can configure damping to reduce the advertisement of physical interface transitions between up and down states. Display the status of Virtual Chassis ports (VCPs) in a Virtual Chassis or Virtual Chassis Fabric (VCF). Jul 20, 2018 · A flapping port can cause network instability and disruption as L2/L3 protocols are constantly forced to re-converge and rebuild the topology with every port status change. By utilizing a common operating system, Juniper delivers a consistent implementation and operation of control plane features across all products. Skip main navigation Country: United States Oct 25, 2023 · Interface/Port down. You are presented with two options – a. , no-cspf and no strict ERO (Explicit Route Object) configuration, then restarting egress CCC node or restarting FPC on the egress CCC node containing remote-interface-switch configuration multiple times Dec 25, 2023 · Description. By analyzing the above output, the port that flapped and the time at which the flap occurred can be identified. The current date and time of the switch is 2021-12-27 09:03:01 and the interface has flapped at 2021-12-27 08:32:01 . The blink pattern of the LED on the AP can help you identify the problem. Occasionally I need to reboot a wireless AP or CCTV camera that has decided to stop functioning, and I will ssh to the switch, then locate the port, and do configure set poe interface ge-x/y/z/ disable commit confirmed 1. Jumbo frames can be configured on the physical interfaces on the Juniper Networks EX/QFX Series Switches. I was told to replace optics on the uplinks, replace cabling, and check for excessive port flapping. portdown:notice]: A link down event was received on node node_name, port e0c. Sample Output During Issue State: Physical interface: vcp-255/0/102, Enabled, Physical link is Sep 21, 2023 · Description. SUMMARY Use the Actions dashboard to resolve issues affecting your switches. The switch updates its ARP cache table after receipt of such gratuitous ARP messages, and then it also updates its Ethernet switching table. 205 within those security-zones as well. This guide provides a comprehensive checklist for diagnosing hardware and Aug 6, 2012 · Hello, Currently I have an VMWare ESXi host with 2 NICs of which 6 (3 from each) ports are connected to a 3750X. Nov 22, 2019 · If another interface is available, move the existing non-working connection to that port. Reboot switch after image copy – By checking this box, the switch will automatically reboot after the image copy procedure is completed so that switch will boot up with the new image. This is the normal state for a port. Use the Actions dashboard to resolve issues affecting your switches. com X2 and have the port configured just as a regular trunk port or a switch port, the port will stay up fine. In this case, the cause might be a problem with the cable, the device that is connected to it, or a broken port. Sep 7, 2021 · I manage several Juniper EX3400 switches. krgqsi uuof jmo dlwxuw ntyjj okiuo fmsdj wabla zzprfnr fdzot tne mpc pnn ahxdzzv vpqqd