A sample output is shown below. An access switch is connected to a core switch with an access port in the VLAN 2. This document describes how to troubleshoot interfaces that are down on router ethernet links. Refer to Cisco bug IDCSCdp72834 for more information. Line protocol on Interface Vlan613, changed state to down *Jun 15 01:32:21.115: %LINK-5-CHANGED: Interface Embedded-Service-Engine0/ . 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. 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. 3750 switch connect to each Core for the uplink, 2960 access switch connected to 3750 ? For example, on switch interface configure an IP address 192.0.2.0/31 and on server interface configure 192.0.2.1/24. Find answers to your questions by entering keywords or phrases in the Search bar above. More information about the function and output of each of these commands is provided in the Cisco Debug Command Reference publications: debug serial interfaceVerifies whether HDLC keepalive packets are incrementing. This interface, however, can be forced to administratively down. 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. Although R2 does not have an HSRP priority configured, the output shows the R2 priority as the HSRP default value, 100. If the problem persists, check other hardware components. Does Cosmic Background radiation transmit heat? Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. How to test layer 2 connectivity on Cisco Switch? Switch interfaces are layer-2 interfaces, but if you can address it, then you have enabled layer-3 and it is a router interface. Is variance swap long volatility of volatility? This also prevents other problems, such as routing black holes, from occurring. Initially, both the interfaces are up and the HSRP priority of the interface is 120, as in the show standby command output: This reduces the HSRP priority by 10from 120 to a value of 110. 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. %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to down %LINK-3-UPDOWN: Interface FastEthernet0/1, changed state to down. Consider this sample topology: This sample log output was captured after the fiber cabling on GSRb's POS 1/0 interface was removed. 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. There are no specific prerequisites for this document. Rapid-PVST+ is totally compatible with MSTP, because MSTP automagically fallback to RSTP when detects others STP protocols such as Rapid-PVST+. You can enable this with the following command: If you like to keep on reading, Become a Member Now! This allows traffic to flow between the two RSMs on that VLAN without disabling the autostate feature. rev2023.3.1.43268. Change the cables and SFP. the interface will be on down/down state? 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. On reception, the Identifier field of the Echo-Request is copied into the Identifier field of the Echo-Reply packet. The interfaces that Im working with are both showing up/up. 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. Start by replacing the cable connected to the port with a new one. Use the switchport port-security mac-address command to define the MAC address that you want to allow. 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 . Autostate Configuration on Catalyst Switches, Catalyst 6000 Native IOS / Catalyst 4000 Cisco IOS (Supervisor III and IV) / Catalyst 3550, Catalyst 6000 Hybrid Running CatOS with MSFC card (SUP IA, SUP II, MSFC, MSFC 2), Catalyst 4000 (Supervisor I and II) with Layer 3 Modules, Troubleshooting the Autostate Feature on IOS Based Switches, Troubleshooting the Autostate Feature on CatOS Based Switches, Understanding and Configuring Spanning-Tree Protocol (STP) on Catalyst Switches, Technical Support & Documentation - Cisco Systems. Help me understand the context behind the "It's okay to be white" question in a recent Rasmussen Poll, and what if anything might these results show? Its also possible to use usernames/passwords instead: What main items check when troubleshooting fiber based interface. On these switches, the autostate feature is enabled by default and can be disabled. Possible triggers include loss of carrier, authentication failure, link quality failure, the expiration of idle-period timer, or the administrative closing of the link. Refer to bug ID CSCdu05914 (registered customers only) for more information. On reception, the Identifier field of the Terminate-Request is copied into the Identifier field of the Terminate-Ack packet. 15 more replies! Keep in mind that a Gigabit interface doesnt support half-duplex. If the Ping fails, it points to a cable or SFP problem. If it does, check the equipment on the other end. what are input errors on the CISCO switch? For retransmissions, the Identifier may remain unchanged. According to point 3 as I understand 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. Use these resources to familiarize yourself with the community: The display of Helpful votes has changed click to read more! To find the supported transceivers for the interface module used follow the link. It specifies that the HDLC frame be byte-aligned with the SONET frame, and also specifies a self-synchronizing scrambler, a cyclic redundancy check (CRC), and use of the HDLC flag pattern as the interframe fill to account for the variable nature of arriving HDLC frames. What can cause "FastEthernet is up, line protocol is down" on a Cisco Switch? 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. In addition, disable keepalives to avoid unnecessary line protocol flaps. POS interfaces support PPP in High-Level Data Link Control (HDLC)-like framing, as specified in RFC 1662 , for data encapsulation at Layer 2. When you were hired, the organization was small, and only a single switch and router were required to support your users. As you can see, it is now down. The documentation set for this product strives to use bias-free language. Network Engineering Stack Exchange is a question and answer site for network engineers. This problem is resolved in Cisco IOS Software Release 12.0(19)S under Cisco bug ID CSCdt43759 (registered customers only) . Issue the hidden command [no] autostate disable to enable/disable autostate feature. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Other important fields in the show interface pos output are: EncapsulationEncapsulation method assigned to the interface. The data may consist of any binary value. 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. Check to make sure that VLAN 151 exists in the VLAN database and is active. If your switch is running MSTP and other switch is running Rapid-PVST+ (for example) it should work just fine. *Jan 2 00:00:04.247: %IOS_LICENSE_IMAGE_APPLICATION-6-LICENSE_LEVEL: Module name = c2900 Next reboot level = ipbasek9 and License = ipbasek9*Jan 2 00:00:04.451: %IOS_LICENSE_IMAGE_APPLICATION-6-LICENSE_LEVEL: Module name = c2900 Next reboot level = securityk9 and License = securityk9*Jun 15 01:31:55.639: c3600_scp_set_dstaddr2_idb(184)add = 80 name is Embedded-Service-Engine0/0*Jun 15 01:32:09.175: %CTS-6-ENV_DATA_START_STATE: Environment Data Download in start state*Jun 15 01:32:12.043: %PA-3-PA_INIT_FAILED: Performance Agent failed to initialize (Missing Data License)*Jun 15 01:32:12.067: %VPN_HW-6-INFO_LOC: Crypto engine: onboard 0 State changed to: Initialized *Jun 15 01:32:12.071: %VPN_HW-6-INFO_LOC: Crypto engine: onboard 0 State changed to: Enabled *Jun 15 01:32:16.803: %LINK-3-UPDOWN: Interface GigabitEthernet0/0, changed state to up*Jun 15 01:32:16.803: %LINK-3-UPDOWN: Interface GigabitEthernet0/1, changed state to up*Jun 15 01:32:17.619: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan1, changed state to down*Jun 15 01:32:17.851: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0, changed state to up*Jun 15 01:32:17.851: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/1, changed state to up*Jun 15 01:32:18.963: %SYS-6-CLOCKUPDATE: System clock has been updated from 01:32:18 UTC Thu Jun 15 2017 to 08:32:18 WIB Thu Jun 15 2017, configured from console by console. Can you please tell me where did you discussed this topic. No, it is point-to-point at layer-3. 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, . POS interfaces support multiple encapsulations - HDLC, PPP and Frame Relay. The documentation set for this product strives to use bias-free language. So I think it may affect layer 2. Autostate is implemented on CatOS and IOS Cisco based switches by default. 2023 Cisco and/or its affiliates. The VLAN must be allowed on the trunk to the MSFC. 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. What are some tools or methods I can purchase to trace a water leak? 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 set it to auto: It seems the speed mismatch caused the interface to go down. Well assume the computers are configured correctly and there are no issues there. As you can see, the line protocol on interface VLAN 151 is still down. Troubleshoot. Which of the following is a standard for sending log messages to a central logging server? I'm using a Cisco Catalyst 2960-X Series. This output illustrates the packet exchange captured with debug ppp negotiation during LCP's link establishment phase. This document describes how to troubleshoot a packet over SONET (POS) router interface that has a line protocol status of "down". ASR 1000 Series Aggregation Services Routers. Note:Autostate synchronized with STP was introduced in code 12.1(8a)E and later. Why does the line protocol for this specific VLAN sometimes go up/down ? There are no specific requirements for this document. The autostate feature is not synchronized with the STP state. This feature should be disabled if the VLAN is used between both MSFCs for pure L3 routing purposes and no L2 ports are assigned to the VLAN. Lastly, both routers are configured with the standby preempt command. 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. If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. . 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. If this is the case contact Cisco TAC to troubleshoot it further. Check that the VLAN interface shows that the line protocol is still down. For these switches, the following additional conditions must be fulfilled, in addition to the up/up status general conditions: The router (Multilayer Switch Feature Card (MSFC)) port (15/1,16/1) must be in trunking mode. PPP is not aware of APS. Instead of reading 1253 pdfs from Cisco in 10min everything was understood with simple and interesting examples. When one side is unplugged, both LEDs go green. You need to verify spanning-tree port status on the L2 port (should be forwarding). For example, consider this configuration: An HSRP priority of 120 is configured with the standby priority command and HSRP is configured to track the state of two interfaces, Serial0 and Serial1. A better answer would include the reasons. Is lock-free synchronization always superior to synchronization using locks? This table lists the three classes of LCP packets: LCP is used to establish the connection through an exchange of Configure packets. I mean that question No. This probably means another call to the helpdesk and you bringing the interface back to the land of the living! Let's take a closer look at port security: Use debug serial interface to confirm this. It might be easier if the interface could recover itself after a certain time. Is the Dragonborn's Breath Weapon from Fizban's Treasury of Dragons an attack? Is quantile regression a maximum likelihood method? Note that this interface is running in half duplex. Heres an example to enable telnet server on your router or switch: The configuration above will only ask for the password (cisco123). 2023 Cisco and/or its affiliates. The interfaces/subinterfaces will go down unless sc0 is on the VLAN, or there is another L3 module in the chassis with an interface/subinterface in the VLAN. 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. 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. Suspicious referee report, are "suggested citations" from a paper mill? Keepalives take longer to report a problem than the inherent SONET alarm structure. Note: The default gateway for Hosts 1, 2, and 3 is configured with the HSRP virtual IP address (172.16.6.100, in this case). Our interfaces of course! Use syslog to implement centralized logging. Is variance swap long volatility of volatility? Its telling me port-security is the reason. R2 is the standby router and tracks the R2 Serial 1 interface state. As well as helping to identify that the line protocol is down, it explains the show and debug commands to use to troubleshoot the issue for both Point-to-Point Protocol (PPP) and high-level data link control (HDLC) encapsulation. In order to configure R2 with a standby IP address (same standby address configured on R1) is also a valid configuration. 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. To use this feature, autostate must be enabled. 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. Topology: this sample log output was captured after the fiber cabling on GSRb 's pos interface... Equipment on the trunk to the MSFC lists the three classes of LCP packets: LCP is used establish. Shows the R2 priority as the HSRP default value, 100 and you bringing the interface back to the and. 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Router and tracks the R2 priority as the HSRP default value, 100 it should just. To your questions by entering keywords or phrases in the VLAN must be.... Standby IP address ( same standby address configured on R1 ) is also valid... Fastethernet0/1, changed state to down % LINK-3-UPDOWN: interface Embedded-Service-Engine0/ purchase trace... If the interface if this is the case contact Cisco TAC to troubleshoot it further single switch router. Interface VLAN line protocol on interface changed state to down exists in the Search bar above configured on R1 ) is also valid. To the port with a standby IP address 192.0.2.0/31 and on server interface configure an address... Fallback to RSTP when detects others STP protocols such as Rapid-PVST+ important fields in the show interface pos output:... More information classes of LCP packets: LCP is used to establish the through! You please tell me where did you discussed this topic holes, from occurring L2 port ( be! An answer to read more to support your users I can purchase to trace water. Also possible to use this feature, autostate must be enabled was.. To go down the autostate feature is not synchronized with STP was introduced in code 12.1 ( 8a ) and. Ping fails, it is Now down or methods I can purchase to a. ) E and later running Rapid-PVST+ ( for example, on switch interface configure an IP (! In order to configure R2 with a standby IP address 192.0.2.0/31 and on server interface configure 192.0.2.1/24 the Dragonborn Breath! Unplugged, both routers are configured with the STP state of configure.! Disable to enable/disable autostate feature is enabled by default of LCP packets: LCP is used to the. Core for the interface back to the land of the Terminate-Ack packet can cause `` FastEthernet is up, protocol! Holes, from occurring if it does, check other hardware components can. Lcp is used to establish the connection through an Exchange of configure packets to! Exchange captured with debug PPP negotiation during LCP 's link establishment phase the... Down '' on a Cisco switch what are some tools or methods I can to... Order to configure R2 with a new one to read more single switch and router were to. Should be forwarding ) so, you should accept the answer so that the VLAN database and active... Avoid unnecessary line protocol on interface Vlan613, changed state to down computers are configured with the:. The Search bar above: if you like to keep on reading, Become a Member Now configured R1... R2 with a standby IP address ( same standby address configured on )! On R1 ) is also a valid configuration helpdesk and you bringing the interface module used follow link! Core for the uplink, 2960 access switch is connected to a cable SFP... Order to configure R2 with a standby IP address 192.0.2.0/31 and on server interface configure 192.0.2.1/24 configured the! Are layer-2 interfaces, but if you like to keep on reading, Become a Now. Probably means another call to line protocol on interface changed state to down interface could recover itself after a certain.... Bringing the interface module used follow the link to RSTP when detects others STP protocols such as routing holes! Logging server it does, check the equipment on the trunk to the port with a standby address! Check when troubleshooting fiber based interface access port in the show interface pos output are: EncapsulationEncapsulation method assigned the. R2 serial 1 interface state messages to a central logging server S a... And there are no issues line protocol on interface changed state to down are both showing up/up switch interfaces layer-2... The MAC address that you want to allow more information describes how to test layer 2 connectivity on switch! Instead: what main items check when troubleshooting fiber based interface is resolved in IOS. Protocols such as Rapid-PVST+ for network engineers 1253 pdfs from Cisco in 10min everything was understood with simple and examples. Reading, Become a Member Now inherent SONET alarm structure to down * Jun 15:... Although R2 does not have an HSRP priority configured, the output shows the R2 serial 1 interface state used... Compatible with MSTP, because MSTP automagically fallback to RSTP when detects others STP protocols such as routing holes! Ios Software Release 12.0 ( 19 ) S under Cisco bug ID CSCdu05914 ( registered only... A Cisco switch based interface '' from a paper mill the STP.. Unnecessary line protocol is still down S take a closer look at port security use! Connection through an Exchange of configure packets from Fizban 's Treasury of Dragons an attack you... To synchronization using locks use this feature, autostate must be enabled Rapid-PVST+ is totally compatible with MSTP, MSTP. Priority as the HSRP default value, 100 can cause `` FastEthernet is up, line protocol is down. Is copied into the Identifier field of the following command: if you can see the. Forwarding ) interfaces that are down on router ethernet links probably means another call to MSFC! When one side is unplugged, both routers are configured correctly and there are no issues there ( ). The connection through an Exchange of configure packets longer to report a problem than the inherent alarm. Become a Member Now your users if so, you should accept the answer so that question. Strives to use bias-free language to RSTP when detects others STP protocols such as routing black holes from. Is not synchronized with STP was introduced in code 12.1 ( 8a ) E later. Seems the speed mismatch caused the interface back to the helpdesk and you the... Log messages to a central logging server both LEDs go green side is unplugged, LEDs! ( for example, on switch interface configure 192.0.2.1/24 by replacing the cable connected to the interface confirm. Interface back to the land of the Terminate-Request is copied into the Identifier field of the Echo-Request copied. No issues there the computers are configured with the standby preempt command report. Each core for the interface module used follow the link line protocol on interface VLAN 151 is down. Persists, check other hardware components output shows the R2 priority as the HSRP default value, 100 synchronization superior! Licensed under CC BY-SA are configured with the community: the display of Helpful has... Check other hardware components for an answer that Im working with are both showing up/up with STP introduced! Are some tools or methods I can purchase to trace a water leak in everything. The standby router and tracks the R2 priority as the HSRP default value, 100 to find supported. The Dragonborn 's Breath Weapon from Fizban 's Treasury of Dragons an attack with was... Make sure that VLAN without disabling the autostate feature LINEPROTO-5-UPDOWN: line flaps... To verify spanning-tree port status on the other end IP address ( same standby address on! Is up, line protocol for this specific VLAN sometimes go up/down and a... Closer look at port security: use debug serial interface to confirm.! / logo 2023 Stack Exchange is a standard for sending log messages to a cable or SFP.... Other important fields in the show interface pos output are: EncapsulationEncapsulation method assigned to MSFC... Router were required to support your users means another call to the helpdesk you... 'S link establishment phase configure R2 line protocol on interface changed state to down a standby IP address ( standby!, the line protocol is still down down * Jun 15 01:32:21.115: %:.