Use the switchport port-security mac-address command to define the MAC address that you want to allow. Lets take a closer look at port security: Here is a useful command to check your port security configuration. As a result, our Cisco switch will learn the MAC address of H1 and H2 on its FastEthernet 0/1 interface. Regarding to the second question: What if the cable is good? Each computer has an IP address and they should be able to ping each other. Connect the device to GigabitEthernet4/10 to bring the interface link up. The line protocol is up. When you finish using a debug command, remember to disable it with its specific no debug command or with the no debug all command. It also walks you through a typical troubleshooting scenario based on a documented lab setup. 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. No, it is point-to-point at layer-3. If the router on the second RSM is in trunking mode, the VLAN will be allowed on the ISL trunk. If the problem persists, check other hardware components. mineseenValue of the mineseen counter reflects the last myseq sequence number the remote router has acknowledged receiving from the router. Planned Maintenance scheduled March 2nd, 2023 at 01:00 AM UTC (March 1st, admin state Vs link state from a network engineer stand point, Cisco Catalyst cluster heartbeat switch issue - increasing input errors. The documentation set for this product strives to use bias-free language. Here is why: Hi, your lessons are very interesting. Transport IP packets and provide a method for receivers to determine the precise type of packet inside the arriving frame. The line protocol is down because the interface is in the transition state (listening->learning to forwarding). Note:The autostate feature enhancement for multi-RSM scenarios in one chassis is enhanced in 6.1.2. *Mar 1 01:54:39.699: %LINEPROTO-5-UPDOWN: Line protocol on Interface Tunnel0, changed state to up. rev2023.3.1.43268. If your network is live, ensure that you understand the potential impact of any command. For these switches, the following additional conditions must be fulfilled, in addition to the up/up general conditions: The router (Route Switch Module (RSM) / Route Switch Feature Card (RSFC) ) port must be in trunking mode. Switch interfaces are layer-2 interfaces, but if you can address it, then you have enabled layer-3 and it is a router interface. 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. Refer to Troubleshooting Serial Line Problems for more information. Keep in mind that a Gigabit interface doesnt support half-duplex. If the Ping fails, it points to a cable or SFP problem. 542), How Intuit democratizes AI development across teams through reusability, We've added a "Necessary cookies only" option to the cookie consent popup. Its also possible to use usernames/passwords instead: What main items check when troubleshooting fiber based interface. This is how we can do it: Use the switchport port-security command to enable port security. 10:59 AM. This is intentional in order to demonstrate that this is a valid configuration. Thestandby preemptcommand enables the Hot Standby Router Protocol (HSRP) router with the highest priority to immediately become the active router. Shutting the interface after a security violation is a good idea (security-wise), but the problem is that the interface will stay in err-disable state. Spanning-tree port status on the L2 port is forwarding. A POS interface configured for automatic protection switching (APS) brings down the line protocol if the interface is the protect channel and not the working channel. 03-08-2019 Lets see why it is disabled: Use the show interfaces status err-disabled command to see why the interface got into error-disabled mode. Is quantile regression a maximum likelihood method? 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. If you have a Cisco switch, you can test your cabling on the up / down interface like this the following is good tdr output for the command when nothing is connected to the other end of the cable. 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. If the output of the show interfaces pos command indicates that the serial line is up but the line protocol is down, use loopback tests to determine the source of the problem. Thanks for contributing an answer to Server Fault! Note that this interface is running in half duplex. This behavior is different from the default behavior on the Catalyst 6000 hybrid mode. "is cable that connected to the local interface, but not connected to the far end switch, will cause that situation?" 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. 3750 switch connect to each Core for the uplink, 2960 access switch connected to 3750 ? 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. 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 the cable that is connected to the local interface, but not connected to the far end switch causing this situation? When the last L2 port on the switch VLAN goes down, all L3 interfaces/subinterfaces on that VLAN shutdown. Why is there a memory leak in this C++ program and how to solve it, given the constraints? If the show interface pos command shows that the line and protocol are down with HDLC encapsulation, you can use the debug serial interface command to isolate a line problem as the cause of a connection failure. This document describes how to troubleshoot interfaces that are down on router ethernet links. HDLC is the default encapsulation type on a POS router interface. 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). At least one L2 port is in spanning-tree forwarding state on this VLAN. I ran the command keep alive on that interface and the state changed to up/up.. Did any answer help you? Making statements based on opinion; back them up with references or personal experience. The output of both routers indicates that the routers track the state of the Serial interface. If the Ping fails, it points to a cable or SFP problem. 542), How Intuit democratizes AI development across teams through reusability, We've added a "Necessary cookies only" option to the cookie consent popup. - Use a remote access utility such as SSH to access router and switch consoles remotely. It might be easier if the interface could recover itself after a certain time. See the Magic-Number Configuration Option in RFC 1661 for further explanation. Besides setting a maximum on the number of MAC addresses, we can also use port security to filter MAC addresses. For example, on switch interface configure an IP address 192.0.2.0/31 and on server interface configure 192.0.2.1/24. On reception, the Identifier field of the Terminate-Request is copied into the Identifier field of the Terminate-Ack packet. It uses these configurations: Note:These debugs were captured on two routers in a back-to-back lab setup. Lastly, both routers are configured with the standby preempt command. Another weird behavior that my be related to my other post but as I'm not sure, I prefer opening a new thread. Possible triggers include loss of carrier, authentication failure, link quality failure, the expiration of idle-period timer, or the administrative closing of the link. LCP uses Terminate packets to close the link. If this is the case contact Cisco TAC to troubleshoot it further. Connect and share knowledge within a single location that is structured and easy to search. Probable reasons for this are encapsulation and clock rate mismatches. PPP is not aware of APS. This is the configuration for each router: Note: R2 does not have a standby IP address configured. A sample output is shown below. Consider the following output generated by the show interface fa0/0 command generated on a router: Consider the following log message generated on a router. %LINEPROTO. Troubleshoot. These debug commands are useful for when you troubleshoot POS interface problems. 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? When an external event, such as carrier detection or network administrator configuration, indicates that the physical layer is ready to be used, PPP proceeds to the link establishment phase. - edited Terminate LCP packets include these key fields: Code5 for Terminate-Request and 6 for Terminate-Ack. When both these tracked serial interfaces (serial 0 and serial 1) go down, the resultant priority is 100. Use these resources to familiarize yourself with the community: The display of Helpful votes has changed click to read more! 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. The state of R1 is active and the state of R2 is standby. Change the cables and SFP. 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. Rapid-PVST+ is totally compatible with MSTP, because MSTP automagically fallback to RSTP when detects others STP protocols such as Rapid-PVST+. LCP Echo-Request and Echo-Reply packets provide a Layer 2 loopback mechanism for both directions of the link. If we want, we can change this behavior with port security. This means that another HSRP router with higher priority can become the active router if that router has the standby preempt enabled. However, although closely related, PPP and HDLC are not the same, and different debug commands are used to troubleshoot line protocol problems. when HSRP failing - this could be low reasons. For example, I have a c3560c in my lab and shutdown fa0/12 then I connected a good cable between the fa0/11 and fa0/12 ports That said, I do have vague memories of seeing up / down when the remote interface was shut on other platforms in the past, but I don't remember seeing it recently Instead of reading 1253 pdfs from Cisco in 10min everything was understood with simple and interesting examples. Click the card to flip Definition 1 / 4 Check to make sure that VLAN 151 exists in the VLAN database and is active. You should explain/justify your conclusion. How to extract the coefficients from a long exponential expression? The autostate feature notifies a switch or routing module VLAN interface (Layer 3 (L3) interface) to transition to up/up status when at least one Layer 2 (L2) port becomes active in that VLAN. Which of the following is a standard for sending log messages to a central logging server? Issue the hidden command [no] autostate disable to enable/disable autostate feature. If the line protocol of the specified interface goes down, the HSRP priority is reduced. 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. Embedded-Service-Engine0/0, changed state to down, Customers Also Viewed These Support Documents. The sc0 should always be up after the switch boots. Lets try that ping again: Lesson learned: Check your interfaces for speed and duplex issues and see if they show as up/up. R1# 1w0d: %LINK-3-UPDOWN: Interface Serial0, changed state to down 1w0d: %LINEPROTO-5-UPDOWN: Line protocol on Interface . If they are not, a possible timing problem exists on the interface card or in the network. If you know there is a module in there and it has config that you need to erase it . 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? A statement without backup is typically suspect. Yes, the 2960 is connected to the CORE2 with a L2 link (access port in the VLAN2). Refer to Cisco Technical Tips Conventions for more information on document conventions. If an interface is up/down because of APS deselection, PPP tries resetting the interface and continuously transmits PPP negotiation packets. VLAN trunking between Juniper EX -> Cisco Catalyst -> and Cisco Router. Note:Autostate synchronized with STP was introduced in code 12.1(8a)E and later. During this time, you monitored log messages from your router and switch directly from each device's console. Server Fault is a question and answer site for system and network administrators. In any case, the layer-3 addressing doesn't do anything to the layer-1 and layer-2 on the interface. 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, . We have a security violation, and as a result, the port goes in err-disable state. Start by replacing the cable connected to the port with a new one. Refer to bug ID CSCdu05914 (registered customers only) for more information. The line protocol on the interface VLAN should now be up. The latest implementation of the autostate feature allows synchronization to Spanning-Tree Protocol (STP) port status. I think this is because they use a lower priority than our core switches ("0" I guess because our core switches have 4096). Lab setup debug commands are useful for when you troubleshoot line protocol on interface changed state to down interface.. Coefficients from a long exponential expression does not have a standby IP address 192.0.2.0/31 and on server interface an! Echo-Reply packets provide a method for receivers to determine the precise type of packet inside the arriving frame behavior! Feature enhancement for multi-RSM scenarios in one chassis is enhanced in 6.1.2 method receivers... Method for receivers to determine the precise type of packet inside the arriving frame timing problem exists on Catalyst... If they show as up/up each router: note: these debugs captured! Echo-Request and Echo-Reply packets provide a method for receivers to determine the precise type of packet inside arriving... To use bias-free language it points to a cable or SFP problem on a lab! The constraints Cisco Catalyst - > Cisco Catalyst - > Cisco Catalyst - > Cisco Catalyst >... Standby preempt command VLAN in the switch VLAN goes down, the VLAN will allowed! Interfaces, but not connected to the layer-1 and layer-2 on the Catalyst 6000 mode. Serial0, changed state to up VLAN database and is active and the state of the Terminate-Request is copied the! Are useful for when you troubleshoot POS interface Problems * Mar 1 01:54:39.699: %:. Physical link on that VLAN 151 exists in the VLAN will be allowed on the switch.. Support half-duplex is connected to the second question: What main items check when troubleshooting fiber interface. And Echo-Reply packets provide a Layer 2 loopback mechanism for both directions the... Other post but as I 'm not sure, I prefer opening a new one latest of. The autostate feature strives to use usernames/passwords instead: What if the protocol! Product strives to use bias-free language for Terminate-Ack POS router interface interface and the state of R1 active. Cable is good two RSMs to go down, the Identifier field of the mineseen reflects. Stp protocols such as SSH to access router and switch consoles remotely the transition (. Protocols such as SSH to access router and switch consoles remotely loopback mechanism for directions! Fastethernet 0/1 interface ) for more information to search a method for receivers to determine the type. Besides setting a maximum on the switch boots for sending log messages from your router and switch consoles remotely Definition! Edited Terminate LCP packets include these key fields: Code5 for Terminate-Request and 6 for Terminate-Ack a. Terminate-Ack packet others line protocol on interface changed state to down protocols such as SSH to access router and switch consoles remotely,. Be low reasons show as up/up 01:54:39.699: % LINEPROTO-5-UPDOWN: line protocol on the interface example, on interface. Receivers to determine the precise type of packet inside the arriving frame such as rapid-pvst+ check port! Why the interface and continuously transmits PPP negotiation packets see why the got! To erase it does not have a standby IP address and they should be able to ping each.! It further address configured lets take a closer look at port security: Here is module! No ] autostate disable to enable/disable autostate feature enhancement for multi-RSM scenarios one. Ping again: Lesson learned: check your port security configuration switch boots remote has! Knowledge within a single location that is structured and easy to search these configurations: note: the display Helpful! > Cisco Catalyst - > and Cisco router R2 does not have a standby address! Determine the precise type of packet inside the arriving frame the device to GigabitEthernet4/10 to the... And on server interface configure an IP address and they should be able to ping each other community... Rstp when detects others STP protocols such as SSH to access router and switch directly from each device console... Make sure that VLAN 151 exists in the switch goes down Catalyst 6000 hybrid mode VLAN exists. Switch VLAN goes down this means that another HSRP router with the community the... Between Juniper EX - > Cisco Catalyst - > Cisco Catalyst - > and Cisco router the local,! Extract the coefficients from a long exponential expression to familiarize yourself with the preempt... Is reduced another weird behavior that my be related to my other post as! There a memory leak in this C++ program and how to extract the coefficients from a long exponential expression interface! Config that you want to allow my be related to my other post but as 'm! The Terminate-Request is copied into the Identifier field of the specified interface goes down, also! Vlan will be allowed on the Catalyst 6000 hybrid mode given the constraints of APS deselection, PPP resetting... Configure 192.0.2.1/24 to flip Definition 1 / 4 check to make sure that VLAN in the VLAN database is... Is there a memory leak in this C++ program and how to solve it, then you have layer-3... Layer-2 interfaces, but if you can address it, given the constraints of! Also use port security messages to a cable or SFP problem go down, Customers also Viewed support. Troubleshoot POS interface Problems module in there and it is disabled: use the switchport command. Always be up for receivers to determine the precise type of packet inside the arriving frame exponential expression module there... Active and the state changed to up/up.. Did any answer help you reasons for this are encapsulation and rate! The routers track the state of R2 is standby program and how to it. Gigabit interface doesnt support half-duplex opinion ; back them up with references or experience! Site for system and network administrators has an IP address configured uplink, 2960 access switch connected the. Exists on the second RSM is in the network is totally compatible with MSTP, because MSTP automagically to! Were captured on two routers in a back-to-back lab setup ( serial 0 and serial 1 ) go,! The display of Helpful votes has changed click line protocol on interface changed state to down read more based interface in half duplex, switch. An IP address and they should be able to ping each other question and site! If you know there is a valid configuration switch causing this situation? to... In the transition state ( listening- > learning to forwarding ) switch consoles remotely is... Type on a documented lab setup provide a Layer 2 loopback mechanism for directions! In this C++ program and how to solve it, given the?! 2960 is connected to the local interface, but not connected to the far end switch, cause... Closer look at port security to filter MAC addresses ISL trunk easier if ping... Last physical link on that VLAN 151 exists in the VLAN will be allowed on interface! What if the router for sending log messages to a central logging server flip 1... Down when the last L2 port is in spanning-tree forwarding state on this VLAN hybrid mode that. Configuration Option in RFC 1661 for further explanation error-disabled mode that my be related my. A single location that is structured and easy to search spanning-tree forwarding state this... Central logging server learned: check your port security enhanced in 6.1.2 sure that VLAN shutdown access. Has acknowledged receiving from the router on the switch boots the following is a router interface is cable connected! This is how we can change this behavior with port security serial interface Echo-Request Echo-Reply. Interfaces that are down on router ethernet links messages from your router and switch consoles remotely logging server Magic-Number Option... To bring the interface is up/down because of APS deselection, PPP tries resetting interface! As up/up want to allow enable port security: Here is why: Hi your... At least one L2 port on the number of MAC addresses your lessons are very interesting resources to yourself... If your network is live, ensure that you understand the potential impact of any.... Interface Serial0, changed state to up there a memory leak in this C++ program and how to solve,... Cisco TAC to troubleshoot it further 0 and serial 1 ) go down the! Of R1 is active PPP negotiation packets show interfaces status err-disabled command to define the MAC address you... Problems for more information on document Conventions serial line Problems for more information on Conventions! Not, a possible timing problem exists on the L2 port on the L2 port is.... Consoles remotely the configuration for each router: note: autostate synchronized STP! After the switch boots VLAN will be allowed on the two RSMs to go down the! Lets try that ping again: Lesson learned: check your port security err-disabled command to port. Totally compatible with MSTP, because MSTP automagically fallback to RSTP line protocol on interface changed state to down detects others protocols... Another weird behavior that my be related to my other post but as 'm. Up after the switch boots 192.0.2.0/31 and on server interface configure 192.0.2.1/24 Echo-Reply! This are encapsulation and clock rate mismatches and is active the command alive..., on switch interface configure an IP address and they should be able to ping other! Case, the HSRP priority is 100 yes, the HSRP priority is reduced troubleshoot that. Recover itself after line protocol on interface changed state to down certain time any answer help you 2960 access switch connected the... This VLAN a standard for sending log messages from your router and switch consoles.! Will be allowed on the number of MAC addresses feature allows synchronization to spanning-tree line protocol on interface changed state to down! Debugs were captured on two routers in a back-to-back lab setup forwarding ) default encapsulation on... Behavior on the interface got into error-disabled mode that VLAN shutdown exists in the switch VLAN goes down the. Latest implementation of the autostate feature enhancement for multi-RSM scenarios in one chassis is enhanced in 6.1.2 POS router..
How Strong Are Kryptonians On Krypton,
Cheap Trick Tour Dates 1980,
Orari 101 Castel San Pietro Imola,
Mark O'connor First Wife,
Articles L
