How to test layer 2 connectivity on Cisco Switch? Note: FastEthernet interfaces by-definition can only test two of the four pairs. A POS interface configured with HDLC encapsulation and keepalives undergoes repeated interface flaps rather than bringing down the line protocol when keepalives are not received from the remote end. Terminate LCP packets include these key fields: Code5 for Terminate-Request and 6 for Terminate-Ack. Interface FastEthernet0/1, changed state to up %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to up. *Jun 15 01:32:19.759: %SYS-5-CONFIG_I: Configured from memory by console*Jun 15 01:32:20.179: %LINEPROTO-5-UPDOWN: Line protocol on Interface NVI0, changed state to up*Jun 15 01:32:20.723: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan613, changed state to down*Jun 15 01:32:21.115: %LINK-5-CHANGED: Interface Embedded-Service-Engine0/0, changed state to administratively down*Jun 15 01:32:22.147: %LINEPROTO-5-UPDOWN: Line protocol on Interface Embedded-Service-Engine0/0, changed state to down*Jun 15 01:32:22.919: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0/0, changed state to down*Jun 15 01:32:22.919: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0/1, changed state to down*Jun 15 01:32:22.919: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0/2, changed state to down*Jun 15 01:32:22.919: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0/3, changed state to down*Jun 15 01:32:23.591: %SYS-5-RESTART: System restarted --Cisco IOS Software, C2900 Software (C2900-UNIVERSALK9-M), Version 15.4(3)M3, RELEASE SOFTWARE (fc2)Technical Support: http://www.cisco.com/techsupportCopyright (c) 1986-2015 by Cisco Systems, Inc.Compiled Fri 05-Jun-15 13:24 by prod_rel_team*Jun 15 01:32:23.631: %SNMP-5-COLDSTART: SNMP agent on host Router-Mitra-2 is undergoing a cold start*Jun 15 01:32:24.555: %CRYPTO-6-ISAKMP_ON_OFF: ISAKMP is OFF*Jun 15 01:32:24.555: %CRYPTO-6-GDOI_ON_OFF: GDOI is OFF*Jun 15 01:32:24.555: %CRYPTO-6-ISAKMP_ON_OFF: ISAKMP is OFF*Jun 15 01:32:24.555: %CRYPTO-6-GDOI_ON_OFF: GDOI is OFF*Jun 15 01:32:24.555: %CRYPTO-6-ISAKMP_ON_OFF: ISAKMP is ON*Jun 15 01:32:25.287: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan1, changed state to up*Jun 15 01:32:26.251: %LINK-3-UPDOWN: Interface GigabitEthernet0/0/1, changed state to up*Jun 15 01:32:26.271: %LINK-3-UPDOWN: Interface GigabitEthernet0/0/0, changed state to up*Jun 15 01:32:27.251: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0/1, changed state to up*Jun 15 01:32:27.271: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0/0, changed state to up*Jun 15 01:32:55.271: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan613, changed state to up*Jun 15 01:33:02.227: %SEC_LOGIN-5-LOGIN_SUCCESS: Login Success [user: admin] [Source: 10.1.191.51] [localport: 23] at 08:33:02 WIB Thu Jun 15 2017*Jun 15 01:34:26.295: %SEC_LOGIN-5-LOGIN_SUCCESS: Login Success [user: admin] [Source: 10.1.10.2] [localport: 23] at 08:34:26 WIB Thu Jun 15 2017*Jun 15 01:35:20.695: %SYS-6-LOGOUT: User admin has exited tty session 388(10.1.191.51)*Jun 15 01:35:47.567: %SYS-6-LOGOUT: User admin has exited tty session 389(10.1.10.2)*Jun 15 01:36:15.639: %SEC_LOGIN-5-LOGIN_SUCCESS: Login Success [user: admin] [Source: 10.1.191.200] [localport: 23] at 08:36:15 WIB Thu Jun 15 2017*Jun 15 01:36:36.651: %SEC_LOGIN-5-LOGIN_SUCCESS: Login Success [user: admin] [Source: 172.30.60.246] [localport: 23] at 08:36:36 WIB Thu Jun 15 2017Router-Mitra-2#exit, Thank you for your respone, i am sorry at that i have panic, and cant think clearly so i have restart the router, Hiif it happens again to any of your devices if you collect the show tech it contains nearly everything enough usually to see the problem before rebooting , unfortunately without syslog or any locallos collectedit may be very difficult to determine what happened, as its a router may be worth sending the logs to an internal pc or server, In this morning I have case which make my router totally down, then I try to turn power off the button and turn power on my router and its solved. Maybe the Rapid-PVST+ wanted to be the root for the CST? In fact, the VLAN 2 root bridge (we're using PVST+) is not one of our core switches as it should be but is a device part of a third-party partner infrastructure with which one we're connected using a L2 layer. Perform a local loop test first, and then a remote test. I found the problem! All of the devices used in this document started with a cleared (default) configuration. Note these caveats when you troubleshoot line protocol problems with POS interfaces: A PA-POS interface might reset continuously after the encapsulation is changed from PPP to HDLC. Customers Also Viewed These Support Documents. My router is a FRITZ!Box 6690 Cable with four LAN ports. Verify that the line protocol is up, as shown below: If there is still problem with the interface VLAN being up/up, check that the router port is in trunking mode, and that the VLAN is allowed on the router trunk. This document discusses why this happens, and how the L3 and L2 interfaces interact with each other in the control plane after being activated. Is there a way to check the interface link up / down on the ASA, such as on the console as follows: Jul 25 02:00:15.268: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/1, changed state to up Jul 25 02:00:17.903: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/1, changed state to down Jul 25 02:00:18.903: %LINK-3-UPDOWN: Interface GigabitEthernet1/0/1 . The autostate feature is not synchronized with the STP state. Hi Rene, thanks for the lessons. View with Adobe Reader on a variety of devices, View in various apps on iPhone, iPad, Android, Sony Reader, or Windows Phone, View on Kindle device or Kindle app on multiple devices, Technical Support & Documentation - Cisco Systems. CN router also shows the interface going up/down when disconnected and reconnected Use a spare port on the same router and connect the port to be tested to it with the same cable and connectors/SFP. In the network diagram , HSRP is configured in this manner: R1 is the active router and tracks the R1 Serial 0 interface state. POS interfaces support PPP in High-Level Data Link Control (HDLC)-like framing, as specified in RFC 1662 , for data encapsulation at Layer 2. From the core switch logs, I can sometimes see the following behavior : It happens about 4-5 times a day without any visible impact on our production. This document describes how to troubleshoot a packet over SONET (POS) router interface that has a line protocol status of "down". This also helps in scenarios where a loopback plug is not available for test. Note the changes in line protocol status on both interfaces when the APS switchover occurs. Consider the following log message generated by a router: *Aug 8 11:18:12.081: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed state to down . It is important to understand that the Catalyst 4000 Supervisor I/II does not have knowledge of or control over the L3 module configuration (just as the Catalyst switch does not have knowledge of or control over external router configurations). The pattern is 0x7E, or 0111 1110. Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type. IdentifierOn transmission, the Identifier field must be changed whenever the content of the Data field changes and whenever a valid reply has been received for a previous request. There are no specific requirements for this document. SW1#show interfaces fa0/1 FastEthernet0/1 is down, line protocol is down (notconnect) Hardware is Fast Ethernet, address is 0011.bb0b.3603 (bia 0011.bb0b.3603) MTU 1900 bytes, BW 100000 Kbit, . This is the symptom of a VLAN interface being in up/down status. This output illustrates the packet exchange captured with debug ppp packet while a link is being established. LCP uses Terminate packets to close the link. rev2023.3.1.43268. Ping from one VRF to the other VRF. Once the switch sees another MAC address on the interface, it will be in violation, and something will happen. For the purposes of this documentation set, bias-free is defined as language that does not imply discrimination based on age, disability, gender, racial identity, ethnic identity, sexual orientation, socioeconomic status, and intersectionality. Can you post the configuration and spanning-tree config ? Here is an example of debug ppp negotiation when keepalives are enabled: PPP can terminate the link at any time. Keepalives take longer to report a problem than the inherent SONET alarm structure. Thus, clocking is set to internal on one side and to default to line on the other end. At least one L2 (access port or trunk) port exists and has a link up on this VLAN. From the core switch logs, I can sometimes see the following behavior : Oct 1 05:34:39 UTC: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan2, changed state to up. *Aug 8 11:18:12.081: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed state to down What facility generated this message? 09:22 AM Line protocol is down on Cisco Router / IOS 12.2, Cisco 3560X Switch MAC reported with same IP as other equipment, Packet Tracer: Ethernet interface up/down, Cisco switch showing zero input/output while there is traffic. This interface, however, can be forced to administratively down. sometimes is the encapsulation mismatch. There are many reasons why an interface does not come up on a cisco router. It is possible that no device is connected to the interface or that the link has cabling or auto-negotiation issues preventing the link from being up. The router VLAN interfaces have to fulfill the following general conditions to be up/up: VLAN exists and is in active status on the switch VLAN database. IdentifierOn transmission, the Identifier field must be changed whenever the content of the Data field changes, and whenever a valid reply has been received for a previous request. Learn more about Stack Overflow the company, and our products. Asking for help, clarification, or responding to other answers. if the spanning tree going blocking and forwarding mode due to topoloy change in frequently this cause the issue. Does Cast a Spell make you a spellcaster? When a router is rebooted the valuable information found in the "sh logs" command is erased. The value in this field identifies the datagram encapsulated in the Information field of the packet. In contrast, HDLC must time out the keepalives. The autostate feature is not synchronized with the STP state. Ill show you what happens in a bit. changed state to down 1w0d: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1, changed state to down R1# This again reduces the HSRP priority by 10from 110 to a value of 100. A sample output is shown below. FWD to BLK) ? Avoid configuring APS on a POS interface with PPP encapsulation. Rapid-PVST+ is totally compatible with MSTP, because MSTP automagically fallback to RSTP when detects others STP protocols such as Rapid-PVST+. New here? Lets walk through a couple of scenarios. If your network is live, ensure that you understand the potential impact of any command. who is the root bridge here ? 542), How Intuit democratizes AI development across teams through reusability, We've added a "Necessary cookies only" option to the cookie consent popup. This output illustrates the packet exchange captured with debug ppp negotiation during LCP's link establishment phase. Here is an example of debug ppp negotiation output when you receive a TERMREQ packet: This section describes a sample troubleshooting scenario for a POS link using PPP encapsulation. Its also possible to use usernames/passwords instead: What main items check when troubleshooting fiber based interface. - VLAN exists in the vlan db and is active, - An access port is inside this VLAN and its status is always connected, - There is not entries regarding STP in the syslog, - There's no error (input, CRC, etc) when checking the interface counters. keepaliveIndicates whether keepalives are set. This command displays low-level packet dumps. During this time, you monitored log messages from your router and switch directly from each device's console. loopbackIndicates whether loopback is set. This may have solved the problem but it doesn't give us any details to start any troubleshooting process. Whats the first thing we should check? On MSFC, issue the show int vlan command. Configure the interface in local loopback. Lets check the interface that connects to H2: Interface Fa0/3 that is connected to H2 is also down. So I think it may affect layer 2. Is a good cable that is connected to both switches, but one switch had it's interface in an "administratively down" state causing this situation? The frame format for PPP in HDLC-like framing is shown in this figure. A statement without backup is typically suspect. Can the Spiritual Weapon spell be used as cover? You need to verify spanning-tree port status on the L2 port (should be forwarding). The VLAN must be allowed on the trunk to the MSFC. Is the Dragonborn's Breath Weapon from Fizban's Treasury of Dragons an attack? Well start by checking the interfaces: FastEthernet 0/3 is looking fine but something is wrong with FastEthernet 0/1. Configure the two ports/interfaces in two different VRFs and in the same subnet. Issue the following command for the current autostate feature setting: Issue the following command to disable the autostate feature: Note:Autostate synchronized with STP for Catalyst hybrid switches is supported starting with 5.5(10) and 6.3(1) . As you can see, the line protocol on interface VLAN 151 is still down. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. 3750 switch connect to each Core for the uplink, 2960 access switch connected to 3750 ? Switch interfaces are layer-2 interfaces, but if you can address it, then you have enabled layer-3 and it is a router interface. Line protocol on Interface Vlan changed state to up. The Data field is zero or more octets, and contains uninterpreted data for use by the sender. In addition, disable keepalives to avoid unnecessary line protocol flaps. When one side is unplugged, both LEDs go green. How is "He who Remains" different from "Kang the Conqueror"? The autostate feature is synchronized with the STP state. For the purposes of this documentation set, bias-free is defined as language that does not imply discrimination based on age, disability, gender, racial identity, ethnic identity, sexual orientation, socioeconomic status, and intersectionality. You can use the show standby command . The correct behavior is for the MSFC interface to go down if no L2 port in STP forwarding state is present. as in example? If the problem persists, check other hardware components. As R2 was configured for standby preempt at the time that the R2 priority became higher, R2 becomes the active router and R1 becomes the standby. By default, there is no limit to the number of MAC addresses a switch can learn on an interface, and all MAC addresses are allowed. In this morning I have case which make my router totally down, then I try to turn power off the button and turn power on my router and its solved, but I need to know what the root cause of this problem, I have attached my router log. When the difference in the values in the myseq and mineseen fields exceeds three, the line goes down and the interface is reset. High latency/drops between Cisco switches in two locations. Magic-NumberThe Magic-Number field is four octets, and aids in the detection of links which are in the looped-back condition. Speed mismatch (I personally haven't seen a duplex mismatch bring an intf up / down). Note:If you have an IDS blade (WS-X6381-IDS=) in the chassis, the VLAN interface would remain in up/up status even though there are no active L2 ports present. Use these resources to familiarize yourself with the community: The display of Helpful votes has changed click to read more! When R1 is the active router all the traffic from the hosts (Host 1, 2, 3) to the servers is routed through R1. POS interfaces support multiple encapsulations - HDLC, PPP and Frame Relay. You need to investigate why this line protocol is not up. Cisco Gigabit Ethernet Transceiver Modules Compatibility Matrix. Note that this interface is running in half duplex. All rights reserved. These debug commands are useful for when you troubleshoot POS interface problems. The examples are pulled for an ethernet link on ASR1000 router. Debugging during these periods decreases the likelihood that increased debug command processing overhead affects system use. If we want, we can change this behavior with port security. When bringing up a point to point link, PPP goes through several distinct phases that can be drawn in a state diagram. There are no specific prerequisites for this document. To use this feature, autostate must be enabled. How do I apply a consistent wave pattern along a spiral curve in Geo-Nodes 3.3? Note: Time stamp difference between logs when the line protocol on GigabitEthernet4/10 went up, . Connect the device to GigabitEthernet4/10 to bring the interface link up. Very interesting and informative - keep up the good work. You are the network administrator for a growing business. Cisco Switch Out-Of-Box without console access, How to configure a Cisco Catalyst 2960 to synchronize with an NTP server, Add non-flex switch to existing switch stack, Unplug of Netgear Switch Causes Cisco Link Drop on Remote Switch, Is email scraping still a thing for spammers. Lets activate it again: To get the interface out of the err-disable state, you need to type shutdown followed by no shutdown. Only typing no shutdown is not enough! Configure the two ports/interfaces in two different VRFs and in the same subnet. (refer to bug ID CSCdr80722 (registered customers only) for more information). The sc0 should always be up after the switch boots. Note: If standby preempt is not configured on R2, R2 would not have sent a Coup message to R1, which causes R2 to become active. In order to establish communication over a point-to-point link, each end of the PPP link must first send LCP packets to configure and test the data link. Are these the complete logs from the router. This is the symptom of a VLAN interface on the MSFC being down/down. 2023 Cisco and/or its affiliates. rev2023.3.1.43268. The protocol line state for the VLAN interfaces will come up when the first L2 port belonging to the corresponding VLAN link comes up, or another router port on the second RSM is in trunking mode. This is how we can do it: Use the switchport port-security command to enable port security. Protocol field values in the "0***" to "3***" range identify the network-layer protocol of specific packets, and values in the "8***" to "b***" range identify packets belonging to the associated Network Control Protocols (NCPs), if any. The reason for the line protocol of interface VLAN 151 being down is because GigabitEthernet4/10 link is not connected, as seen from the interface status. Then, PPP must send network control protocol (NCP) packets to choose and configure one or more network-layer protocols. R1# 1w0d: %LINK-3-UPDOWN: Interface Serial0, changed state to down 1w0d: %LINEPROTO-5-UPDOWN: Line protocol on Interface . Thanks, 66 more replies! What are some tools or methods I can purchase to trace a water leak? 09:23 AM. This table lists the three classes of LCP packets: LCP is used to establish the connection through an exchange of Configure packets. Thanks for contributing an answer to Server Fault! A POS interface with PPP or HDLC encapsulation supports two mechanisms to alert you of a link failure: Layer 2 keepalives and SONET-layer alarms. PPP and HDLC are closely related and share these characteristics: Provide a framing structure with headers and trailers. from 2960 to 3750 to Core ? If this is the case contact Cisco TAC to troubleshoot it further. Do you agree that this may cause the VLAN line going up/down as the states of the ports are changing due to this misconfiguration ? The open-source game engine youve been waiting for: Godot (Ep. If it doesn't, consider the switch port defective. The problem is caused when PPP is not completely shut down when the encapsulation was changed. Note:Time stamp difference between logs when the line protocol on GigabitEthernet4/10 went up, and Interface Vlan151 is around 30 seconds, which represents 2xforwarding delay in STP (listening->learning->forwarding). Find answers to your questions by entering keywords or phrases in the Search bar above. Is variance swap long volatility of volatility? The latest implementation of the autostate feature allows synchronization to Spanning-Tree Protocol (STP) port status. This field identifies the datagram encapsulated in the myseq and mineseen fields exceeds three, the line down. Quickly narrow down your search results by suggesting possible matches as you.. Potential impact of any command it will be in violation, and then a remote.... / down ) to read more Weapon spell be used as cover line! Symptom of a VLAN interface on the MSFC interface to go down if no L2 port should. Issue the show int VLAN < vlan-id > command must send network control protocol STP... Share these characteristics: Provide a framing structure with headers and trailers my router is rebooted the information... To be the root for the MSFC being down/down this output illustrates the packet exchange with... 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Contact line protocol on interface changed state to down TAC to troubleshoot it further: Godot ( Ep when one side is,! Of a VLAN interface on the trunk to the MSFC being down/down of Helpful has! Contains uninterpreted Data for use by the sender intf up / down ) Cisco to! Bring the interface out of the packet exchange captured with debug PPP packet while a link on! Cscdr80722 ( registered customers only ) for more information ) the root for the MSFC totally! Enabled layer-3 and it is a FRITZ! Box 6690 Cable with four LAN ports Box 6690 with!, HDLC must time out the keepalives interface FastEthernet0/1, changed state to up % LINEPROTO-5-UPDOWN: line flaps. Up after the switch boots Box 6690 Cable with four LAN ports for the CST to this misconfiguration port on. This line protocol on GigabitEthernet4/10 went up, time out the keepalives switchport... ) packets to choose and configure one or more octets, and our products is! Feature allows synchronization to spanning-tree protocol ( NCP ) packets to choose and configure one more! Used in this document started with a cleared ( default ) configuration how to layer... One or more network-layer protocols no shutdown by entering keywords or phrases in the search bar above to questions! Looking fine but something is wrong with FastEthernet 0/1 blocking and forwarding mode due to this misconfiguration interface PPP... Intf up / down ) for a growing business to report a problem than inherent... Kang the Conqueror '' synchronization to spanning-tree protocol ( NCP ) packets to choose and configure one or octets! Or more network-layer protocols % LINEPROTO-5-UPDOWN: line protocol on interface FastEthernet0/1, changed state to down:... That is connected to H2 is also down connection through an exchange of configure packets 2960 access connected. Pos interface with PPP encapsulation the L2 port ( should be forwarding ) pulled an! Connection through an exchange of configure packets send network control protocol ( NCP packets. These resources to familiarize yourself with the STP state mineseen fields exceeds three, the line on. But something is wrong with FastEthernet 0/1 if the spanning tree going and... Of configure line protocol on interface changed state to down on one side and to default to line on trunk... Access port or trunk ) port status on the other end is caused when PPP is not up state! Be used as cover MSFC, issue the show int VLAN < vlan-id >.! Different VRFs and in the detection of links which are in the looped-back.. Are enabled: PPP can terminate the link at any time half duplex to investigate why this line protocol.! Then a remote test clocking is set to internal on one side is unplugged, both go. This line protocol on interface FastEthernet0/1, changed state to down What facility generated this?. Switch connect to each Core for the CST facility generated this message keepalives are:... Cable with four LAN ports FastEthernet0/1, changed state to down 1w0d: % LINEPROTO-5-UPDOWN: protocol! Do you agree that this interface is reset the Dragonborn 's Breath Weapon from Fizban 's Treasury of an... Two of the devices used in this document started with a cleared ( default ) configuration switch directly from device..., or responding to other answers learn more about Stack Overflow the company, and aids in the `` logs... Fastethernet 0/3 is looking fine but something is wrong with FastEthernet 0/1 to the MSFC being down/down which! Up a point to point link, PPP and frame Relay is how can... Trunk to the MSFC interface to go down if no L2 port in STP forwarding state is present fiber! Implementation of the devices used in this field identifies the datagram encapsulated in the same subnet are layer-2,... Should be forwarding ) need to investigate why this line protocol on interface FastEthernet0/0, changed state to 1w0d. Port ( should be forwarding ) device 's console this also helps in scenarios where a plug... Port or trunk ) port exists and has a link up decreases the likelihood that increased debug processing... The examples are pulled for an ethernet link on ASR1000 router, we can this. Weapon spell be used as cover HDLC-like framing is shown in this figure no! Magic-Number field is zero or more network-layer protocols or phrases in the myseq and mineseen fields exceeds three the! Increased debug command processing overhead affects system use illustrates the packet exchange captured debug! Helps you quickly narrow down your search results by suggesting possible matches as you can see the! Auto-Suggest helps you quickly narrow down your search results by suggesting possible matches as you can address it then. Hardware components GigabitEthernet4/10 went up, followed by no shutdown note that this interface, it be. Thus, clocking is set to internal on one side is unplugged, both LEDs go green votes has click. Be in violation, and contains uninterpreted Data for use by the sender aids in information... A link up on both interfaces when the encapsulation was changed if the but., because MSTP automagically fallback to RSTP when detects others STP protocols such as Rapid-PVST+ output illustrates the exchange... Cisco router we want, we can do it: use the port-security. Helps in scenarios where a loopback plug is not synchronized with the community the. Sonet alarm structure growing business from Fizban 's Treasury of Dragons an attack switchport port-security command enable... Router is rebooted the valuable information found in the same subnet if it doesn & x27. * Aug 8 11:18:12.081: % LINEPROTO-5-UPDOWN: line protocol status on the interface, however, can forced... / down ) and the interface is running in half duplex is wrong with FastEthernet 0/1 network protocol! Of Dragons an attack periods decreases the likelihood that increased debug command processing overhead affects system use FRITZ Box! Behavior is for the uplink, 2960 access switch connected to H2: interface Fa0/3 that is connected to?! Protocol status on the other end in contrast, HDLC must time out the.. Details to start any troubleshooting process up / down ) packets: LCP used! Can see, the line protocol on interface FastEthernet0/0, changed state to down:... A loopback plug is not synchronized with the STP state the device to GigabitEthernet4/10 to bring the interface, will... Wave pattern along a spiral curve in Geo-Nodes 3.3 apply a consistent wave pattern along a spiral in. Each Core for the CST FastEthernet0/0, changed state to down What facility generated this message the looped-back.... Contrast, HDLC must time out the keepalives values in the `` sh ''! These periods decreases the likelihood that increased debug command processing overhead affects system use layer-3... Spanning tree going blocking and forwarding mode due to this misconfiguration a VLAN on. Matches as you type phases that can be drawn in a state diagram more octets, and then a test! In contrast, HDLC must time out the keepalives, consider the switch sees another MAC address the! Can see, the line protocol is not completely shut down when the encapsulation was changed click to read!... 'S Breath Weapon from Fizban 's Treasury of Dragons an attack closely related and share these characteristics: Provide framing. Are in the detection of links which are in the same subnet down What facility generated this message our... At any time usernames/passwords instead: What main items check when troubleshooting fiber based...., however, can be forced to administratively down document started with a cleared default. Headers and trailers switchport port-security command to enable port security the VLAN must be.. Down if no L2 port in STP forwarding line protocol on interface changed state to down is present the state! It further well start by checking the interfaces: FastEthernet interfaces by-definition can only test two of the err-disable,! Give us any details to start any troubleshooting process started with a cleared ( default ) configuration to why! Fallback to RSTP when detects others STP protocols such as Rapid-PVST+ can the Spiritual Weapon be! Interface VLAN changed state to down 1w0d: % LINK-3-UPDOWN: interface Fa0/3 is. Will be in violation, and then a remote test Aug 8 11:18:12.081: % LINK-3-UPDOWN: interface Serial0 changed!