line protocol on interface changed state to down

If they are not, a possible timing problem exists on the interface card or in the network. This test verfies the packet path inside the router all the way till PLIM( Physical Layer Interface Module). "is cable that connected to the local interface, but not connected to the far end switch, will cause that situation?" This debug captures the value of the protocol field in the PPP packet. At this point the R2 HSRP priority is higher than R1, and R2 takes over as the active router. PPP reacts more quickly to link state changes since LCP comes down immediately. Jordan's line about intimate parties in The Great Gatsby? If the router and port ASICs are properly initialised the interface must come up and self ping must work. Terminate LCP packets include these key fields: Code5 for Terminate-Request and 6 for Terminate-Ack. My switch is permanently changing the state of port GigabitEthernet1/0/1 from up to down and from down to up. Why does the line protocol for this specific VLAN sometimes go up/down ? On reception of an Echo-Request in the LCP Opened state, an Echo-Reply must be transmitted. Browse other questions tagged, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site. is cable that connected to the local interface, but not connected to the far end switch, will cause that situation? 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. To use this feature, autostate must be enabled. Planned Maintenance scheduled March 2nd, 2023 at 01:00 AM UTC (March 1st, Will a Cisco 2514 router work properly with a Cisco Catalyst 3500 series switch? Side A would be admin down, and side B would be down/down. LCP uses Terminate packets to close the link. R1# 1w0d: %LINK-3-UPDOWN: Interface Serial0, changed state to down 1w0d: %LINEPROTO-5-UPDOWN: Line protocol on Interface . Note:If autostate is enabled and there are no ports active on a specific VLAN in the switch, the interface on RSM remains up if there is more than one RSM. Of course, we dont want people to bring their own switches and connect them to our network, so we want to prevent this from happening. You need to verify spanning-tree port status on the L2 port (should be forwarding). Also, is there any history somewhere that records the changes of states of the ports (ie. This problem is reported against the PA-POS in Cisco bug ID CSCdk30893 (registered customers only) and resolved in Cisco bug ID CSCdk18777 (registered customers only) and Cisco bug ID CSCdk13757 (registered customers only) for various interfaces that support PPP and HDLC encapsulation. Consider this sample topology: This sample log output was captured after the fiber cabling on GSRb's POS 1/0 interface was removed. In a back-to-back setup between two routers, pulling one of the fiber strands breaks Layer 1 connectivity, and both POS interfaces change state to down/down. Lets take a look at the following situation: In the topology above, someone connected a cheap (unmanaged) switch that they brought from home to the FastEthernet 0/1 interface of our Cisco switch. This is the configuration for each router: Note: R2 does not have a standby IP address configured. Would the reflected sun's radiation melt ice in LEO? 10-02-2019 Aug 4 14:48:36.323 UTC: %LINEPROTO-5-UPDOWN: Line protocol on Interface Embedded-Service-Engine0/0, changed state to down I've rebooted a few times, tried removing all connections to the device. Refer to bug ID CSCdu07244 (registered customers only) for more information. You need to investigate why this line protocol is not up. Maybe the Rapid-PVST+ wanted to be the root for the CST? This diagram illustrates the protocol stack used on a POS interface. 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. The value in this field identifies the datagram encapsulated in the Information field of the packet. Spanning-tree port status is in listening yet. To find the supported transceivers for the interface module used follow the link. If the cable is faulty, it could cause up / down status. 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. The state of R1 is active and the state of R2 is standby. Which of the following is a standard for sending log messages to a central logging server? Browse other questions tagged, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site. Lets check it out: We can look at the port security configuration and we see that only 1 MAC address is allowed. This allows traffic to flow between the two RSMs on that VLAN without disabling the autostate feature. The command below shows that the VLAN exists and is active on the switch. Are these the complete logs from the router. Other than quotes and umlaut, does " mean anything special? if the cable is good, both sides will be down. (refer to bug ID CSCdr80722 (registered customers only) for more information). Asking for help, clarification, or responding to other answers. Line Protocol Is Down With PPP RFC 1661 defines PPP as a protocol. The frame format for PPP in HDLC-like framing is shown in this figure. If the ping works, it indicates the local node, local ports/connectors and the cable are good. is there a chinese version of ex. Suspicious referee report, are "suggested citations" from a paper mill? Lets set duplex to auto: Ill change the interface to duplex auto so the switch can figure it out by itself. 2023 Cisco and/or its affiliates. In contrast, HDLC must time out the keepalives. You should explain/justify your conclusion. On the switch, issue the sh vlan , sh port mod/port (L2 port), sh trunk mod/port (if the L2 port is a trunk), and sh spantree commands. This section discusses an easier way to isolate the failure to either the Layer 1 or Layer 2 or which endpoint device. The examples are pulled for an ethernet link on ASR1000 router. Then it shows what appear to be the 4 physical interfaces all go into a down 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. I have configured port security, so only one MAC address is allowed. It only takes a minute to sign up. When the last L2 port on the switch VLAN goes down, all L3 interfaces/subinterfaces on that VLAN shutdown. 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. For example, on switch interface configure an IP address 192.0.2.0/31 and on server interface configure 192.0.2.1/24. This is the symptom of a VLAN interface on the MSFC being down/down. I can put some really messed up layer-3 addressing on the interfaces to the point that layer-3 doesn't work, but that doesn't do anything to bring down layer-1 or layer-2. You can use this to only allow specific MAC addresses. Change the cables and SFP. 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. Thank you for your response , this is my complete log that i have, =~=~=~=~=~=~=~=~=~=~=~= PuTTY log 2017.06.15 08:47:58 =~=~=~=~=~=~=~=~=~=~=~=sh loh gSyslog logging: enabled (0 messages dropped, 3 messages rate-limited, 0 flushes, 0 overruns, xml disabled, filtering disabled), Console logging: level debugging, 41 messages logged, xml disabled, filtering disabled Monitor logging: level debugging, 0 messages logged, xml disabled, filtering disabled Buffer logging: level debugging, 41 messages logged, xml disabled, filtering disabled Exception Logging: size (4096 bytes) Count and timestamp logging messages: disabled Persistent logging: disabled. This document describes how to troubleshoot a packet over SONET (POS) router interface that has a line protocol status of "down". Symptom: Dec 30 03:34:54: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/26, changed state to down Dec 30 03:35:04: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/26, changed state to up Dec 30 03:49:50: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/26, changed state to down Dec 30 03:50:00: %LINEPROTO-5-UPDOWN: Line protocol on . Hi, can you provide the configs of 3 switches? As you can see, the line protocol on interface VLAN 151 is still down. - Changed cable from straight to cross over and back - Cable has been traced back and is definitely connected to correct port on CN router. This diagram shows an example that uses the standby preempt command in conjunction with the standby track command. The output of both routers indicates that the routers track the state of the Serial interface. I don't know why, but the switch couldn't work properly with that port. I found the problem! 3750 switch connect to each Core for the uplink, 2960 access switch connected to 3750 ? When troubleshooting fibre based interfaces, there are some specific items that you should check: First of all, all of the issues brought up by Rene in this lesson are applicable to fibre optic connections as well. This document discusses why this happens, and how the L3 and L2 interfaces interact with each other in the control plane after being activated. In this example we have a switch in the middle and two computers that are connected to it. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. All rights reserved. View with Adobe Reader on a variety of devices, Understanding Loopback Modes on Cisco Routers, Technical Support & Documentation - Cisco Systems, Configure-Request, Configure-Ack, Configure-Nak and Configure-Reject, Code-Reject, Protocol-Reject, Echo-Request, Echo-Reply, and Discard-Request. This test is particularly useful when the loopback test is successful to identify which end of the link is at fault or if it is an interoperability issue between devices. I wonder what can cause that the first line output of the command "show interfaces" will be: "fastEthernet is up, line protocol is down". Switch interfaces are layer-2 interfaces, but if you can address it, then you have enabled layer-3 and it is a router interface. Priority is determined first by the configured priority value, and then by the IP address. Oct 1 05:35:25 UTC: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan2, changed state to down. What happens if the serial 0 interface of R1 goes down? If the router on the second RSM is in trunking mode, the VLAN will be allowed on the ISL trunk. I think the real issue here is more the VLAN protocol line going up and down and up than the HSRP because the HSRP state seems to change whenever the VLAN procotol goes down and then up. Perform a local loop test first, and then a remote test. Cisco ASR 1000 Series Aggregation Services Routers, 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, There are many reasons why an interface does not come up on a cisco router. A sample output is shown below. The VLAN must be allowed on the router trunk. - 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. Is variance swap long volatility of volatility? 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) . See the Magic-Number Configuration Option in RFC 1661 for further explanation. In order to configure R2 with a standby IP address (same standby address configured on R1) is also a valid configuration. Once the switch sees another MAC address on the interface, it will be in violation, and something will happen. Because no decrement value is specified in the standby track command, the HSRP priority is decremented by the default value of 10 when the tracked interface goes down. What tool to use for the online analogue of "writing lecture notes on a blackboard"? Cisco ethernet interfaces are normally down / down if they don't have a link. Connect the device to GigabitEthernet4/10 to bring the interface link up. You can use the show standby command to verify this: Next, the second tracked interfaceSerial 1is brought down: This again reduces the HSRP priority by 10from 110 to a value of 100. In this lesson well take a look how to troubleshoot a variety of interface issues. This document describes how the standby preempt and standby track commands work together and how to use them. There are many reasons why an interface does not come up on a cisco router. There are no specific prerequisites for this document. Heres an example for the console and SSH: Configuring Cisco router for the first time. This output illustrates the packet exchange captured with debug ppp negotiation during LCP's link establishment phase. Server Fault is a question and answer site for system and network administrators. 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. Our interfaces of course! All of the devices used in this document started with a cleared (default) configuration. After verifying cables and connectors we can check duplex and speed errors. Network Engineering Stack Exchange is a question and answer site for network engineers. How to test layer 2 connectivity on Cisco Switch? (Refer to the APS Technology Support Page for more information.). 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 autostate feature is not synchronized with the STP state. I finally noticed that the other router interface it was connected to had no keep alive. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Check the status of port 3/1 assigned to VLAN 15. On the RSM, issue the show int command. Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type. Regarding to the second question: What if the cable is good? If you are lucky you might get a duplex message through CDP that tells you that there is a duplex mismatch. as in example? 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). No, it is point-to-point at layer-3. IP addressing, at layer-3, does not affect the layer-1/2. What can I do? Lets try another ping (maybe we get lucky): Too bad, the ping is not working. DataThe Data field is zero or more octets, and contains uninterpreted data for use by the sender. 542), How Intuit democratizes AI development across teams through reusability, We've added a "Necessary cookies only" option to the cookie consent popup. The VLAN must be allowed on the trunk to the MSFC. Note: Time stamp difference between logs when the line protocol on GigabitEthernet4/10 went up, . This interface, however, can be forced to administratively down. Hi Rene, thanks for the lessons. Connect and share knowledge within a single location that is structured and easy to search. The correct behavior is for the MSFC interface to go down if no L2 port in STP forwarding state is present. A better answer would include the reasons. Are there conventions to indicate a new item in a list? This sample output captures the LCP link configuration stage on a POS interface: Note:A POS interface configured with PPP encapsulation continually tries to establish a PPP session. It uses these configurations: Note:These debugs were captured on two routers in a back-to-back lab setup. Whats the first thing we should check? @RonMaupin But, when I config ip address with /31 mask, it become a real p2p link. when HSRP failing - this could be low reasons. 2023 Cisco and/or its affiliates. In addition, disable keepalives to avoid unnecessary line protocol flaps. Additionally, you should keep the following in mind when troubleshooting fibre based interfaces: Hi Laz, What can cause "FastEthernet is up, line protocol is down" on a Cisco Switch? Note that this interface is running in half duplex. This is fixed through bug ID CSCdt75094 (registered customers only) in 6.2.2 , 6.3.1 and later releases. The documentation set for this product strives to use bias-free language. Alternately, when performing this test, execute the show controller pos command, which displays SONET alarms. The next issue is about port-security, well use the same topology: Same topology but theres a different problem here. A statement without backup is typically suspect. In order to keep the interface VLAN up/up without having a dedicated L2 port assigned to the VLAN, the autostate feature can be disabled. These LCP packets include these key fields: Code9 for Echo-Request and 10 for Echo-Reply. Learn more about how Cisco is using Inclusive Language. yourseenReflects the value of the myseq sequence number the router has received in a keepalive packet from the remote router. Besides setting a maximum on the number of MAC addresses, we can also use port security to filter MAC addresses. If the Ping fails, it points to a cable or SFP problem. Multi-RSM allows the interfaces on the two RSMs to go down when the last physical link on that VLAN in the switch goes down. The latest implementation of the autostate feature allows synchronization to Spanning-Tree Protocol (STP) port status. If it doesn't, consider the switch port defective. The sc0 should always be up after the switch boots. Learn more about how Cisco is using Inclusive Language. An access switch is connected to a core switch with an access port in the VLAN 2. Use a spare port on the same router and connect the port to be tested to it with the same cable and connectors/SFP. Troubleshootcan be tedious and painful when the failure happens in the field with too many variables - the problem could be due to Layer 1 - SFP (Small Form-Factor Pluggable)/cables/connectors/patch panel or layer 2 - the port on the router (either end or one end of the link). Change the cables and SFP. Line protocol on Interface Vlan613, changed state to down *Jun 15 01:32:21.115: %LINK-5-CHANGED: Interface Embedded-Service-Engine0/ . Well start by checking the interfaces: FastEthernet 0/3 is looking fine but something is wrong with FastEthernet 0/1. Refer to Understanding Loopback Modes on Cisco Routers for guidance. Is the Dragonborn's Breath Weapon from Fizban's Treasury of Dragons an attack? The interfaces that Im working with are both showing up/up. Click the card to flip Definition 1 / 4 As you can see, it is now down. Each computer has an IP address and they should be able to ping each other. Probable reasons for this are encapsulation and clock rate mismatches. %LINEPROTO. Issue the hidden command [no] autostate disable to enable/disable autostate feature. A Cisco 12000 Series POS interface in APS working or protect mode can become stuck in an up/down state (even with a loopback) when APS is disabled. It only takes a minute to sign up. According to point 3 as I understand 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 . If your switch is running MSTP and other switch is running Rapid-PVST+ (for example) it should work just fine. Although R2 does not have an HSRP priority configured, the output shows the R2 priority as the HSRP default value, 100. 10:55 PM Lets try that ping again: Lesson learned: Check your interfaces for speed and duplex issues and see if they show as up/up. Why is there a memory leak in this C++ program and how to solve it, given the constraints? Now well generate some traffic to cause a violation: Im pinging to some bogus IP addressthere is nothing with IP address 1.2.3.4; I just want to generate some traffic. Does Cast a Spell make you a spellcaster? I wonder what can cause the first line output of the command show interfaces to be: FastEthernet is up, line protocol is down. Can you please tell me where did you discussed this topic. Thus, clocking is set to internal on one side and to default to line on the other end. Has Microsoft lowered its Windows 11 eligibility criteria? . Note the highlighted parts of the display and comments: The Cisco IOS Command Reference states that the line protocol field status "indicates whether the software processes that handle the line protocol consider the line usable (that is, keepalives are successful) or whether it has been taken down by an administrator.". All rights reserved. Lets check the interface that connects to H2: Interface Fa0/3 that is connected to H2 is also down. The best answers are voted up and rise to the top, Not the answer you're looking for? You can see the violation mode is shutdown and that the last violation was caused by MAC address 0090.cc0e.5023 (H1). I mean that question No. 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. Does anything else happen? Configure the two ports/interfaces in two different VRFs and in the same subnet. Note:Autostate synchronized with STP was introduced in code 12.1(8a)E and later. debug ppp errorsShows PPP errors (such as illegal or malformed frames) associated with PPP connection negotiation and operation. Now, if the R1 serial 0 interface comes back up, the R1 priority is 105, again. Learn more about Stack Overflow the company, and our products. Protocol field values in the "c***" to "f***" range identify packets as link-layer Control Protocols (such as LCP). For more information on document conventions, see the Cisco Technical Tips Conventions. Check the status of interface gig 4/10 assigned to VLAN 151. VLAN trunking between Juniper EX -> Cisco Catalyst -> and Cisco Router. Lets set it to auto: It seems the speed mismatch caused the interface to go down. how is these connected L2 ? No, it is point-to-point at layer-3. Configure the interface in local loopback. How is "He who Remains" different from "Kang the Conqueror"? The line protocol on an interface configured with PPP comes up only when all LCP and NCP sessions are negotiated successfully. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. One function is determination when a link is functioning properly and when it is failing. *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, did you check the show version before it was rebooted to see what it provided or take a show tech before it was rebooted , rebooting it would have cleared the errors and reset the logs , do you have syslog in place on the router so the logs went to any other server. The last MAC address seen on the interface is 000c.2928.5c6c. upgrading to decora light switches- why left switch has white and black wire backstabbed? On MSFC, issue the show int vlan command. The autostate feature is synchronized with the STP state, and this behavior cannot be modified unless autostate is enabled. 09:23 AM. HDLC is the default encapsulation type on a POS router interface. An access switch is connected to a core switch with an access port in the VLAN 2. R2 is the standby router and tracks the R2 Serial 1 interface state. When the difference in the values in the myseq and mineseen fields exceeds three, the line goes down and the interface is reset. 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. Use these resources to familiarize yourself with the community: The display of Helpful votes has changed click to read more! In any case, the layer-3 addressing doesn't do anything to the layer-1 and layer-2 on the interface. The autostate feature is synchronized with the STP state. Exceptions may be present in the documentation due to language that is hardcoded in the user interfaces of the product software, language used based on RFP documentation, or language that is used by a referenced third-party product. this can only confirm based on some more inputs. From the access switch, the uplink is always up. If an interface is up/down because of APS deselection, PPP tries resetting the interface and continuously transmits PPP negotiation packets. However, Layer 2 keepalives are useful because they check the path from line card CPU to line card CPU, rather than framer to framer as SONET-level alarms do. Ill show you what happens in a bit. Make sure that at least one L2 port is in spanning-tree forwarding state on this VLAN. The documentation set for this product strives to use bias-free language. debug ppp negotiationShows PPP packets transmitted during PPP startup, where PPP options are negotiated. Lets take a closer look at it: Hmm it says err-disabled. From the remote router and share knowledge within a single location that connected... Such as illegal or malformed frames ) associated with PPP RFC 1661 PPP. The command below shows that the routers track the state of R2 is the for... The console and SSH: Configuring Cisco router going up/down as the states of the protocol field in the line... Switch, will cause that situation? for example, on switch interface 192.0.2.1/24. The uplink is always up bad, the line protocol on interface changed state to down shows the R2 HSRP priority configured, ping! How to test Layer 2 connectivity on Cisco switch mode is shutdown and that the VLAN must be allowed the. Technology Support Page for more information on document conventions, see the Magic-Number configuration in... Configure an IP address with /31 mask, it indicates the local interface, it is now down security and... There any history somewhere that records the changes of states of the packet keepalives to avoid unnecessary line protocol GigabitEthernet4/10! Node, local ports/connectors and the state of the protocol field in the field! % LINK-3-UPDOWN: interface Serial0, changed state to down and from down to up and paste this URL your... Is `` He who Remains '' different from `` Kang the Conqueror '' bring interface! Errors ( such as illegal or malformed frames ) associated with PPP comes up only when all and! Shows the R2 Serial 1 interface state Kang the Conqueror '' output of both routers indicates that VLAN! In RFC 1661 for further explanation priority as the HSRP default value, and will... This can only confirm based on some more inputs field identifies the datagram encapsulated in LCP. To flow between the two RSMs to go down it does n't, consider the can. A look how to use this feature, autostate must be allowed on the trunk to the end! The display of Helpful votes has changed click to read more only when all LCP and NCP sessions are.. Not affect the layer-1/2 this misconfiguration properly initialised the interface to go down Module. Be low reasons was caused by MAC address on the switch can figure it out by itself citations '' a. `` is cable that connected to the top, not the answer you 're looking for looking fine but is! Standby preempt and standby track commands work together and how to troubleshoot a of! Not have a standby IP address ( same standby address configured vlan-id >.. Loopback Modes on Cisco routers for guidance VLAN 151 is still down LCP packets include these key fields Code9... Why an interface is up/down because of APS deselection, PPP tries resetting the that. The layer-3 addressing does n't, consider the switch sees another MAC address on the same and... Valid configuration to other answers that is structured and easy to search difference in the information field of the feature... Are there conventions to indicate a new item in a list but if are. Of an Echo-Request in the switch from down to up LINK-3-UPDOWN: interface that! Clocking is set to internal on one side and to default to line on the interface is up/down of! Given the constraints on GSRb 's POS 1/0 interface was removed cabling on GSRb 's POS 1/0 interface was.! Interface does not have a standby IP address and they should be able to ping each other, Echo-Reply... You provide the configs of 3 switches 6.3.1 and later be tested to it with the topology... White and black wire backstabbed cleared ( default ) configuration negotiated successfully were. Umlaut, does `` mean anything special exceeds three, the line protocol is down with connection... Is a router interface it was connected to the top, not the answer you looking. This document describes how the standby preempt command in conjunction with the STP state you can use this feature autostate... < vlan-id > command PPP connection negotiation and operation type on a Cisco router and Cisco for. Anything to the APS Technology Support Page for more information on document conventions, see Magic-Number! Not connected to the second question: what if the ping works, it be... Vlan613, changed state to down PPP reacts more quickly to link state changes since LCP down. All of the following is a router interface the layer-1/2 these key fields: Code5 for Terminate-Request and for... On two routers in a list output illustrates the protocol Stack used on Cisco! The HSRP default value, 100 should always be up after the fiber cabling on GSRb 's POS interface... Spanning-Tree protocol ( STP ) port status on the same subnet be low reasons this VLAN computers that are to. Sun 's radiation melt ice in LEO remote router example for the MSFC down/down! A list RSMs to go down when the last MAC address 0090.cc0e.5023 H1. Interfaces are normally down / down if no L2 port in the values in the network HDLC is Dragonborn. Anything to the MSFC being down/down on ASR1000 router always be up after the fiber cabling on GSRb 's 1/0. Umlaut, does not have an HSRP priority is determined first by the.... Shows that the routers track the state of R1 goes down and the are... Sonet alarms has changed click to read more default value, and this behavior can not be modified autostate. Click to line protocol on interface changed state to down more and 10 for Echo-Reply to Understanding Loopback Modes on routers! Information field of the autostate feature is synchronized with the STP state history somewhere that the! Then by the sender contrast, HDLC must time out the keepalives MSFC interface to down! Question and answer site for network engineers internal on one side and to default line. Shown in this document describes how the standby track commands work together and how to this... May cause the VLAN must be allowed on the MSFC being down/down and when it is now.! Link is functioning properly and when it is now down perform a local test... Sonet alarms what appear to be the 4 physical interfaces all go into a down.! Ppp options are negotiated R2 HSRP priority is determined first by the IP address and. Or Layer 2 connectivity on Cisco switch further explanation PPP packet to line on the all... Such as illegal or malformed frames ) associated with PPP RFC 1661 for further explanation cause the must., does not come up on a POS router interface LINK-5-CHANGED: interface Serial0, changed state down! Interface issues go up/down network Engineering Stack Exchange is a router interface changing due to this RSS,! Synchronization to spanning-tree protocol ( STP ) port status on the number of MAC.! Properly with that port did you discussed this topic now, if the trunk., if the cable is good, both sides will be in,! Check duplex and speed errors VLAN line going up/down as the states the. Would the reflected sun 's radiation melt ice in LEO are not, possible... Also a valid configuration myseq and mineseen fields exceeds three, the line protocol flaps card flip... Work just fine up, connect and share knowledge within a single location that connected... Line about intimate parties in the network properly and when it is failing C++. Fault is a question and answer site for system and network administrators VLAN 15 are pulled an... Frame format for PPP in HDLC-like framing is shown in this lesson well take a closer at. And then a remote test of both routers indicates that the other interface! Are negotiated successfully lesson well take a closer look at it: Hmm it says err-disabled switch! Captured with debug PPP negotiationShows PPP packets transmitted during PPP startup, where PPP options are negotiated points to central... Core for the online analogue of `` writing lecture notes on a Cisco router and 6 for Terminate-Ack POS! Vlan interface on the interface, however, can be forced to administratively down subscribe to misconfiguration. Network Engineering Stack Exchange Inc ; user contributions licensed under CC BY-SA use to! A Cisco router log messages to a central logging server format for PPP in framing. Did you discussed this topic is also a valid configuration to default to line on the RSM issue... Configured port security to filter MAC addresses R2 HSRP priority configured, the line goes down a POS interface use! Cables and connectors we can look at it: Hmm it says err-disabled reacts more quickly link! Message through CDP that tells you that there is a standard for sending log to... Umlaut, does not come up and self ping must work the Magic-Number configuration Option in RFC 1661 PPP! In HDLC-like framing is shown in this lesson well take a look how solve... A possible timing problem exists on the trunk to the far end switch, will cause that situation ''. Good, both sides will be in violation, and side B would be admin,. Is shown in this document describes how the standby preempt command in conjunction with the STP state and... Can see the violation mode is shutdown and that the VLAN 2 configure 192.0.2.1/24 issue. Do n't know why, but not connected to a central logging server with access! This is the Dragonborn 's Breath line protocol on interface changed state to down from Fizban 's Treasury of Dragons an?! Configure an IP address ( same standby address configured on R1 ) is also down why this line protocol interface. Answer site for system and network administrators the next issue is about port-security, well use the same:! For guidance memory leak in this example we have a link this section discusses an easier way to isolate failure... % LINK-3-UPDOWN: interface Embedded-Service-Engine0/, clocking is set to internal on one side and to to!

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