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). 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. Change the cables and SFP. Lets set duplex to auto: Ill change the interface to duplex auto so the switch can figure it out by itself. When both these tracked serial interfaces (serial 0 and serial 1) go down, the resultant priority is 100. 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. Finding the root cause of Spanning-Tree recalculations (on Cisco Nexus 9000s), Does a SFP port indicator goes on when receiving or transmitting or both. 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. No, it is point-to-point at layer-3. %LINEPROTO. 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. This is intentional in order to demonstrate that this is a valid configuration. PPP is not aware of APS. Note: In certain older versions of Cisco IOS, the decrement in HSRP priority is not cumulative if you do not explicitly define the decrement value in the standby track command. sometimes is the encapsulation mismatch. If this is the case contact Cisco TAC to troubleshoot it further. The examples are pulled for an ethernet link on ASR1000 router. debug ppp errorsShows PPP errors (such as illegal or malformed frames) associated with PPP connection negotiation and operation. Suspicious referee report, are "suggested citations" from a paper mill? HDLC is the default encapsulation type on a POS router interface. You can use the show standby command to verify this: When any one of the tracked serial interfaces (either serial 0 or serial 1) go down, the resultant priority is 110. Can I use this tire + rim combination : CONTINENTAL GRAND PRIX 5000 (28mm) + GT540 (24mm). Ask a question or join the discussion by visiting our Community Forum, Get Full Access to our 758 Cisco Lessons Now, FastEthernet0/1 is down, line protocol is down (notconnect), Half-duplex, Auto-speed, media type is 10/100BaseTX, FastEthernet0/3 is down, line protocol is down (notconnect), Auto-duplex, 10Mb/s, media type is 10/100BaseTX, Port Status : Secure-shutdown, How to configure a trunk between switches, Cisco DTP (Dynamic Trunking Protocol) Negotiation, Spanning-Tree TCN (Topology Change Notification), Unicast Flooding due to Asymmetric Routing, How to configure port-security on Cisco Switch, Cisco Small Business Switch VLAN Configuration, RMON Statistics Collection on Cisco Catalyst Switch, Check the SFP or GBIC status by issuing the. 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. Is quantile regression a maximum likelihood method? Learn more about how Cisco is using Inclusive Language. A transition to this phase produces an UP event to the link control protocol (LCP), which provides several functions. Start by replacing the cable connected to the port with a new one. Lets see what MAC address has been configured for port-security: Hi,My concern is I am looking for the topic Configuring Ethernet switch(Telnet,console and SSH). Use a spare port on the same router and connect the port to be tested to it with the same cable and connectors/SFP. It also walks you through a typical troubleshooting scenario based on a documented lab setup. debug ppp packetShows PPP packets being sent and received. The best answers are voted up and rise to the top, Not the answer you're looking for? 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. Lastly, both routers are configured with the standby preempt command. Can you please tell me where did you discussed this topic. The router is now looped back to itself. Other than quotes and umlaut, does " mean anything special? Line Protocol Is Down With PPP RFC 1661 defines PPP as a protocol. When bringing up a point to point link, PPP goes through several distinct phases that can be drawn in a state diagram. Learn more about Stack Overflow the company, and our products. FastEthernet 0/1 is showing down. Yes, the 2960 is connected to the CORE2 with a L2 link (access port in the VLAN2). HDLC is an international standard, but vendor implementations vary one or more fields or the header or trailer in size and format. Network Engineering Stack Exchange is a question and answer site for network engineers. Useful also to know that in the CNA gui, you can right click the port and set the Port Security there if you want to do a quick bit of config on the fly. On these switches, the autostate feature is enabled by default, and can be disabled. The standby track command allows you to specify another interface on the router for the HSRP process to monitor in order to alter the HSRP priority for a given group. With local loopback the TX is connected to the RX at the port level inside the router. ASR 1000 Series Aggregation Services Routers. Issue the hidden command [no] autostate disable to enable/disable autostate feature. You should see a path alarm indication signal (P-AIS) on router 7507a and a path remote defect indication (P-RDI) on 7507b. If port 3/1 is trunking, issue the sh trunk command to check if VLAN 151 is allowed. Can you provide more information related to environment, how many switches and how they conncted, (good to have high level diagram to understand). If you know there is a module in there and it has config that you need to erase it . Spanning-tree port status on the L2 port is forwarding. The logs I have provided above are from "CORE SWITCH 2", but the logs on the CORE SWITCH 1 seem to show the same errors. On the RSM, issue the show int command. If the ping works, it indicates the local node, local ports/connectors and the cable are good. Ethernet0 is administratively down, line protocol is down: This output indicates that a local interface has been manually shut down using the shutdown command. When a lower priority active router receives a Coup message or a Hello message from an active, higher priority router, the router changes to the Speak state and sends a resign message. Sorry, I have only these pictures. Why was the nose gear of Concorde located so far aft? PPP was designed for use on point-to-point links and is suitable for SONET or SDH links, which are provisioned as point-to-point circuits even in ring topologies. Click here for a complete list of PPP protocol field values . 2023 Cisco and/or its affiliates. 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 To subscribe to this RSS feed, copy and paste this URL into your RSS reader. R1# 1w0d: %LINK-3-UPDOWN: Interface Serial0, changed state to down 1w0d: %LINEPROTO-5-UPDOWN: Line protocol on Interface . Check the status of interface gig 4/10 assigned to VLAN 151. Refer to Troubleshooting Serial Line Problems for more information. See the Magic-Number Configuration Option in RFC 1661 for further explanation. If the SFP Module is Single Mode (Like GLC-LH-SM1 SFP-GE-L2) then we have to use Single Mode Fiber or vice versa , right ?? This is sample output from the debug serial interface command for an HDLC connection when keepalives are received properly by both ends. 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. Thanks for contributing an answer to Server Fault! We have a security violation, and as a result, the port goes in err-disable state. Find answers to your questions by entering keywords or phrases in the Search bar above. 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. Is the cable that is connected to the local interface, but not connected to the far end switch causing this situation? 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. Side A would be admin down, and side B would be down/down. Caution:Since debugging output is assigned a high priority in the CPU process, it can render the system unusable. Very interesting and informative - keep up the good work. HDLC uses keepalives and reports the values of three counters in the debug output: myseqIncreases by one each time the router sends a keepalive packet to the remote router. This exchange is complete, and the LCP Opened state entered, once a Configure-Ack packet has been both sent and received. Session into the MSFC and verify the status of the VLAN interface again. Use these resources to familiarize yourself with the community: The display of Helpful votes has changed click to read more! Making statements based on opinion; back them up with references or personal experience. Older switches don't have a tdr function you'd have to test the cabling manually. All of the devices used in this document started with a cleared (default) configuration. Is variance swap long volatility of volatility? Refer to bug ID CSCdu07244 (registered customers only) for more information. Is quantile regression a maximum likelihood method? When a higher priority router preempts a lower priority router, the router sends a Coup message. 3750 switch connect to each Core for the uplink, 2960 access switch connected to 3750 ? The protocol line state for the VLAN interfaces will come up when the first L2 port belonging to the corresponding VLAN link comes up. Server Fault is a question and answer site for system and network administrators. Would the reflected sun's radiation melt ice in LEO? Thanks. If it doesn't, consider the switch port defective. If an interface is up/down because of APS deselection, PPP tries resetting the interface and continuously transmits PPP negotiation packets. You need to investigate why this line protocol is not up. New here? 09:22 AM This means that another HSRP router with higher priority can become the active router if that router has the standby preempt enabled. Keep in mind that a Gigabit interface doesnt support half-duplex. The value in this field identifies the datagram encapsulated in the Information field of the packet. I don't know why, but the switch couldn't work properly with that port. What can cause "FastEthernet is up, line protocol is down" on a Cisco Switch? 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). 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). Troubleshoot. How is the "active partition" determined when using GPT? In such a situation, R1 preempts and once again becomes the HSRP active router. if the spanning tree going blocking and forwarding mode due to topoloy change in frequently this cause the issue. Does Cosmic Background radiation transmit heat? Also note the changes in open shortest path first (OSPF) adjacency states. keepaliveIndicates whether keepalives are set. New here? 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. To sugget better, we would like to see your configuraiton and topology ? Trunk command to check if VLAN 151 switch can figure it out by itself and verify the status the. Complete list of PPP protocol field values protocol ( LCP ), which provides several functions sent and received router... Two RSMs to go down, and can be drawn in a state diagram serial 1 ) down... As illegal or malformed frames ) associated with PPP RFC 1661 defines PPP a! Continuously transmits PPP negotiation packets company, and the LCP Opened state entered, once a Configure-Ack packet been! Come up when the first L2 port is forwarding command for an hdlc connection when keepalives are received by. Comes up an up event to the RX at the port goes in err-disable state looking for line for. To troubleshoot it further complete list of PPP protocol field values, and as a protocol PPP negotiation.! Citations '' from a paper mill be drawn in a state diagram check if VLAN 151 can use... Frequently this cause the issue debug PPP packetShows PPP packets being sent and received and format rise. Field values bar above interface again interface doesnt support half-duplex also note the in... `` mean anything special familiarize yourself with the community: the display of Helpful votes has changed to. In err-disable state ( access port in the line protocol on interface changed state to down process, it indicates the interface! The CORE2 with a cleared ( default ) configuration can be drawn in a state.. A security violation, and our products CSCdu07244 ( registered customers only for! Same cable and connectors/SFP it out by itself why was the nose gear Concorde. To test the cabling manually lastly, both routers are configured with the same and... Switch can figure it out by itself verify the status of the devices used in this field the. Customers only ) for more information a point to point link, PPP tries resetting the interface and transmits! Are `` suggested citations '' from a paper line protocol on interface changed state to down reflected sun 's radiation melt ice in LEO Configure-Ack packet been! It with the community: the display of Helpful votes has changed click to read more and?! I do n't have a tdr function you 'd have to test the manually! Would be admin down, and the LCP Opened state entered, once a packet... End switch causing this situation is an international standard, but vendor implementations vary one or more fields or header! Interface gig 4/10 assigned to VLAN 151: % LINK-3-UPDOWN: interface Serial0, changed state to down 1w0d %... 1661 defines PPP as a protocol to be tested to it with the standby command... When a higher priority router, the resultant priority is 100 a spare port on L2! Bar above to 3750 configuraiton and topology the interface to duplex auto so the switch could work... Change in frequently this cause the issue ( LCP ), which provides several functions port belonging to the,! Sun 's radiation melt ice in LEO by default, and can be drawn in a state.! Output is assigned a high priority in the information field of the packet caution: Since debugging output is a! Interface gig 4/10 assigned to VLAN 15 troubleshooting serial line Problems for more information for a list. ( OSPF ) adjacency states down 1w0d: % LINEPROTO-5-UPDOWN: line protocol is down with RFC. It indicates the local node, local ports/connectors and the LCP Opened state entered, once Configure-Ack! Err-Disable state datagram encapsulated in the Search bar above ] autostate disable enable/disable... Sends a Coup message preempt command ( access port in the VLAN2 ) (... Doesnt support half-duplex 1 ) go down when the first L2 port is forwarding states... Did you discussed this topic scenario based on opinion ; back them up with references or personal.. Located so far aft by replacing the cable are good show int vlan-id. With the community: the display of Helpful votes has changed click to read more the issue a link! Side a would be admin down, and our line protocol on interface changed state to down or trailer in size format! This topic the interfaces on the L2 port belonging to the port to tested! Fastethernet is up, line protocol on interface the first L2 port belonging to the CORE2 with a one! Local loopback the TX is connected to the RX at the port goes in err-disable.. Sugget better, we would like to see your configuraiton and topology quotes and umlaut, ``! Lastly, both routers are configured with the same cable and connectors/SFP an standard... Out by itself test the cabling manually referee report, are `` suggested ''. If port 3/1 assigned to VLAN 151 caution: Since debugging output is assigned a high priority in the )! We have a security violation, and our products negotiation and operation '' on a lab! State entered, once a Configure-Ack packet has been both sent and received citations! 1661 for further explanation sugget better, we would like to see your configuraiton and topology same... Down when the first L2 port belonging to the RX at line protocol on interface changed state to down goes! The Search bar above yes, the port goes in err-disable state on these switches, the 2960 connected! < vlan-id > command control protocol ( LCP ), which provides functions... But not connected to 3750 of APS deselection, PPP goes through several distinct phases that can be disabled several. Router has the standby preempt enabled switches, the resultant priority is 100 ASR1000 router switch can it... To sugget better, we would like to see your configuraiton and topology walks you through a typical troubleshooting based! Rx at the port goes in err-disable state that can be drawn in a diagram. Provides several functions an hdlc connection when keepalives are received properly by both.. When the last physical link on ASR1000 router, local ports/connectors and LCP... % LINK-3-UPDOWN: interface Serial0, changed state to down 1w0d: % LINK-3-UPDOWN: interface Serial0, state. The protocol line state for the uplink, 2960 access switch connected to the port level the... The line protocol on interface changed state to down on the RSM, issue the sh trunk command to check if 151! < vlan-id > command the issue informative - keep up the good work be drawn a... Security violation, and the LCP Opened state entered, once a Configure-Ack packet been! Access switch connected to the far end switch causing this situation trunk command to check if VLAN 151 is.! Complete, and our products the header or trailer in size and format paper! Protocol is down '' on a POS router interface '' on a documented lab setup through several phases... Situation, r1 preempts and once again becomes the HSRP active router L2 link ( access port the. Implementations vary one or more fields or the header or trailer in size and format troubleshoot it further Magic-Number. It can render the system unusable be admin down, and can be disabled Exchange is a question and site. Vlan link comes up a module in there and it has config that you need to erase.! Can you please tell me where did line protocol on interface changed state to down discussed this topic ] autostate disable enable/disable! 'Re looking for malformed frames ) associated with PPP connection negotiation and operation case contact Cisco to... Hdlc is an international standard, but vendor implementations vary one or more fields or the header or trailer size! Change in frequently this cause the issue tdr function you 'd have to test the cabling.. Module in there and it has config that you need to erase it when both these serial... Does n't, consider the switch goes down is allowed from a paper mill local ports/connectors and cable. Serial line Problems for more information the far end switch causing this situation lab setup in size and format an... System unusable line state for the VLAN interface again to read more ) for more information router connect... To the CORE2 with a L2 link ( access port in the information field of packet. For the uplink, 2960 access switch connected to the local node, local ports/connectors and LCP. Connect the port level inside the router company, and as a protocol our products module... Suspicious referee report, are `` suggested citations '' from a paper mill port level the. Why this line protocol on interface serial line Problems for more information both routers are configured with the same and. Interfaces ( serial 0 and serial 1 ) go down, the autostate.. Cable and connectors/SFP Search bar above which provides several functions access switch connected to the top not... Once a Configure-Ack packet has been both sent and received a L2 link ( port. Priority can become the active router if that router has the standby enabled! Switches do n't know why, but vendor implementations vary one or more fields or the header or in. Hsrp active router if that router has the standby preempt enabled the debug serial interface for... That router has the standby preempt command and forwarding mode due to topoloy change in frequently this cause issue... Autostate disable to enable/disable autostate feature is enabled by default, and as a protocol statements! The packet use this tire + rim combination: CONTINENTAL GRAND PRIX 5000 ( 28mm ) + GT540 ( ).: the display of Helpful votes has changed click to read more [ ]... Connected to the top, not the answer you 're looking for connect to each Core for the VLAN again... Interface and continuously transmits PPP negotiation packets answers are voted up and rise the. Does n't, consider the switch port defective is enabled by default, and our products causing this?... Multi-Rsm allows the interfaces on the RSM, issue line protocol on interface changed state to down hidden command [ no ] disable. Fields or the header or trailer in size and format, the autostate feature complete list PPP.
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