And besides, please elaborate when you mean "router totally down". If we want, we can change this behavior with port security. You should see a path alarm indication signal (P-AIS) on router 7507a and a path remote defect indication (P-RDI) on 7507b. GigabitEthernet interfaces can test all four pairs. I'm using a Cisco Catalyst 2960-X Series. I have checked the spanning-tree configuration and found out something abnormal. I mean that question No. HDLC is an international standard, but vendor implementations vary one or more fields or the header or trailer in size and format. Check to make sure that VLAN 151 exists in the VLAN database and is active. This is intentional in order to demonstrate that this is a valid configuration. Keepalives are disabled automatically on most POS router hardware. 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. If it does, check the equipment on the other end. In this lesson well take a look how to troubleshoot a variety of interface issues. When R1 and R2 exchange HSRP hellos, R2 learns the standby IP address from R1. Now, if the R1 serial 0 interface comes back up, the R1 priority is 105, again. 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. Heres an example to enable telnet server on your router or switch: The configuration above will only ask for the password (cisco123). rev2023.3.1.43268. The end of the field is indicated by the Length. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. 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 document describes how the standby preempt and standby track commands work together and how to use them. However, speed has been set to 10 Mbit while this interface is a FastEthernet (100Mbit) link. 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. For this reason, use debug commands only to troubleshoot specific problems or during troubleshooting sessions with Cisco technical support staff. 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. Note that this interface is running in half duplex. Server Fault is a question and answer site for system and network administrators. Debugging during these periods decreases the likelihood that increased debug command processing overhead affects system use. Its telling me port-security is the reason. Note:If you have an IDS blade (WS-X6381-IDS=) in the chassis, the MSFC interface would remain in up/up status even though there are no active L2 ports present. 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. How to test layer 2 connectivity on Cisco Switch? 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. 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). 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 end of the field is indicated by the Length. Heres what you will see: We have a security violation, and as a result, the port goes in err-disable state. Refer toCisco Technical Tips Conventions for more information on document conventions. Troubleshoot. The protocol line state for the VLAN interfaces will come up when the first L2 port belonging to the corresponding VLAN link comes up. 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. 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. What we see so far seems to begin with a normal boot process. Alternately, when performing this test, execute the show controller pos command, which displays SONET alarms. What can I do? 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. Autostate is implemented on CatOS and IOS Cisco based switches by default. Can you provide more information related to environment, how many switches and how they conncted, (good to have high level diagram to understand). 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. Thanks Lus! I finally noticed that the other router interface it was connected to had no keep alive. 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. 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. (refer to bug ID CSCdr80722 (registered customers only) for more information). At least one L2 (access port or trunk) port exists and has a link up on this VLAN. You can use the show standby command . For retransmissions, the Identifier may remain unchanged. When bringing up a point to point link, PPP goes through several distinct phases that can be drawn in a state diagram. On these switches, the autostate feature is enabled by default, and can be disabled. The command below shows that the VLAN exists and is active on the switch. 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. Use these resources to familiarize yourself with the community: The display of Helpful votes has changed click to read more! When one side is unplugged, both LEDs go green. To find the supported transceivers for the interface module used follow the link. Is the Dragonborn's Breath Weapon from Fizban's Treasury of Dragons an attack? Does Cast a Spell make you a spellcaster? upgrading to decora light switches- why left switch has white and black wire backstabbed? The frame format for PPP in HDLC-like framing is shown in this figure. In order to configure R2 with a standby IP address (same standby address configured on R1) is also a valid configuration. When R2 becomes the active router all the traffic from the hosts to the servers is routed through R2. Learn more about Stack Overflow the company, and our products. 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. R1# 1w0d: %LINK-3-UPDOWN: Interface Serial0, changed state to down 1w0d: %LINEPROTO-5-UPDOWN: Line protocol on Interface . 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. This document helps to understand the autostate feature and its characteristics. The reason for the line protocol of interface VLAN 151 being down is because GigabitEthernet4/10 link is not connected, as seen from the interface status. Does Cosmic Background radiation transmit heat? as in example? Learn more about how Cisco is using Inclusive Language. At this point the R2 HSRP priority is higher than R1, and R2 takes over as the active router. Moreover, it is best to use debug commands during periods of low network traffic and fewer users. Embedded-Service-Engine0/0, changed state to down, Customers Also Viewed These Support Documents. It only takes a minute to sign up. Is the set of rational points of an (almost) simple algebraic group simple? is there a chinese version of ex. In this configuration, keepalives are the mechansim to bring the link down. This diagram illustrates the protocol stack used on a POS interface. In contrast, HDLC must time out the keepalives. This could indicate a layer 1 problem like a broken cable, wrong cable (crossover instead of straight-through) or maybe a bad NIC. 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. For the purposes of document, the output of show interface pos is as this output shows. From the access switch, the uplink is always up. This is sample output from the debug serial interface command for an HDLC connection when the remote interface is shut and the local interface misses more than three keepalives. When the last L2 port on the switch VLAN goes down, all L3 interfaces/subinterfaces on that VLAN shutdown. Lets set it to auto: It seems the speed mismatch caused the interface to go down. In the question, the interface is layer-1, and the line protocol is layer-2. The documentation set for this product strives to use bias-free language. Connect and share knowledge within a single location that is structured and easy to search. No, it is point-to-point at layer-3. I have configured port security, so only one MAC address is allowed. This is how we can do it: Use the switchport port-security command to enable port security. The best answers are voted up and rise to the top, Not the answer you're looking for? On reception, the Identifier field of the Echo-Request is copied into the Identifier field of the Echo-Reply packet. 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? You are the network administrator for a growing business. So I have a good intuition that the issues comes from here. On reception of an Echo-Request in the LCP Opened state, an Echo-Reply must be transmitted. In each case, a higher value is of greater priority. When the difference in the values in the myseq and mineseen fields exceeds three, the line goes down and the interface is reset. - Changed cable from straight to cross over and back - Cable has been traced back and is definitely connected to correct port on CN router. Issue the following command to view the current autostate feature setting: Issue the following command to disable the multi-RSM feature in autostate: Note:Disabling multi-RSM is an additional feature of autostate. Perform a local loop test first, and then a remote test. Due to this, the autostate feature will not work on L3 module interfaces if the L3 module is not properly configured. If you are unlucky its possible that your interface goes down. Oct 1 05:35:25 UTC: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan2, changed state to down. 09:22 AM 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.". 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. Line protocol on Interface Vlan613, changed state to down *Jun 15 01:32:21.115: %LINK-5-CHANGED: Interface Embedded-Service-Engine0/ . When a higher priority router preempts a lower priority router, the router sends a Coup message. Change the cables and SFP. This section discusses an easier way to isolate the failure to either the Layer 1 or Layer 2 or which endpoint device. 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 . Refer to bug ID CSCdu05914 (registered customers only) for more information. This probably means another call to the helpdesk and you bringing the interface back to the land of the living! The link issues are quite common when the network is brought up for the first time or with interconnections which involve different Cisco/vendor devices. 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. My router is a FRITZ!Box 6690 Cable with four LAN ports. 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. The protocol line state for the management interface VLAN on the MSFC will always be up. If your network is live, ensure that you understand the potential impact of any command. See the Magic-Number Configuration Option in RFC 1661 for further explanation. However the interface exists even if the module isn't present. Is the cable that is connected to the local interface, but not connected to the far end switch causing this situation? FastEthernet 0/1 is showing down. this can only confirm based on some more inputs. 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. when HSRP failing - this could be low reasons. When both these tracked serial interfaces (serial 0 and serial 1) go down, the resultant priority is 100. Lets take a closer look at port security: Here is a useful command to check your port security configuration. If you are working in a live network, ensure that you understand the potential impact of any command before using it. CN router also shows the interface going up/down when disconnected and reconnected However, although closely related, PPP and HDLC are not the same, and different debug commands are used to troubleshoot line protocol problems. . This test excludes the SFP and the cables in the packet path. The remote router stores this value in its yourseen counter and sends that value in a keepalive packet to the router. If the router on the second RSM is in trunking mode, the VLAN will be allowed on the ISL trunk. The line protocol being down indicates a clocking or framing problem. The last MAC address seen on the interface is 000c.2928.5c6c. This document does not cover Frame Relay encapsulation. We have a security violation, and as a result, the port goes in err-disable state. 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 Would the reflected sun's radiation melt ice in LEO? Can the Spiritual Weapon spell be used as cover? What tool to use for the online analogue of "writing lecture notes on a blackboard"? After verifying cables and connectors we can check duplex and speed errors. A better answer would include the reasons. Another weird behavior that my be related to my other post but as I'm not sure, I prefer opening a new thread. 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 diagram from RFC 1661 illustrates the format of a PPP keepalive packet. Lets take a closer look at it: Hmm it says err-disabled. These debug commands are useful for when you troubleshoot POS interface problems. Lets try that ping again: Lesson learned: Check your interfaces for speed and duplex issues and see if they show as up/up. Switch interfaces are layer-2 interfaces, but if you can address it, then you have enabled layer-3 and it is a router interface. 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. Gongratulations Ren, here it is a very useful lesson. Thus, clocking is set to internal on one side and to default to line on the other end. 2023 Cisco and/or its affiliates. And as you can see, the HSRP state is therefore impacted. Configure the two ports/interfaces in two different VRFs and in the same subnet. Are there conventions to indicate a new item in a list? Lets set duplex to auto: Ill change the interface to duplex auto so the switch can figure it out by itself. Use the switchport port-security mac-address command to define the MAC address that you want to allow. *Jun 15 01:32:19.759: %SYS-5-CONFIG_I: Configured from memory by console*Jun 15 01:32:20.179: %LINEPROTO-5-UPDOWN: Line protocol on Interface NVI0, changed state to up*Jun 15 01:32:20.723: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan613, changed state to down*Jun 15 01:32:21.115: %LINK-5-CHANGED: Interface Embedded-Service-Engine0/0, changed state to administratively down*Jun 15 01:32:22.147: %LINEPROTO-5-UPDOWN: Line protocol on Interface Embedded-Service-Engine0/0, changed state to down*Jun 15 01:32:22.919: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0/0, changed state to down*Jun 15 01:32:22.919: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0/1, changed state to down*Jun 15 01:32:22.919: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0/2, changed state to down*Jun 15 01:32:22.919: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0/3, changed state to down*Jun 15 01:32:23.591: %SYS-5-RESTART: System restarted --Cisco IOS Software, C2900 Software (C2900-UNIVERSALK9-M), Version 15.4(3)M3, RELEASE SOFTWARE (fc2)Technical Support: http://www.cisco.com/techsupportCopyright (c) 1986-2015 by Cisco Systems, Inc.Compiled Fri 05-Jun-15 13:24 by prod_rel_team*Jun 15 01:32:23.631: %SNMP-5-COLDSTART: SNMP agent on host Router-Mitra-2 is undergoing a cold start*Jun 15 01:32:24.555: %CRYPTO-6-ISAKMP_ON_OFF: ISAKMP is OFF*Jun 15 01:32:24.555: %CRYPTO-6-GDOI_ON_OFF: GDOI is OFF*Jun 15 01:32:24.555: %CRYPTO-6-ISAKMP_ON_OFF: ISAKMP is OFF*Jun 15 01:32:24.555: %CRYPTO-6-GDOI_ON_OFF: GDOI is OFF*Jun 15 01:32:24.555: %CRYPTO-6-ISAKMP_ON_OFF: ISAKMP is ON*Jun 15 01:32:25.287: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan1, changed state to up*Jun 15 01:32:26.251: %LINK-3-UPDOWN: Interface GigabitEthernet0/0/1, changed state to up*Jun 15 01:32:26.271: %LINK-3-UPDOWN: Interface GigabitEthernet0/0/0, changed state to up*Jun 15 01:32:27.251: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0/1, changed state to up*Jun 15 01:32:27.271: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0/0, changed state to up*Jun 15 01:32:55.271: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan613, changed state to up*Jun 15 01:33:02.227: %SEC_LOGIN-5-LOGIN_SUCCESS: Login Success [user: admin] [Source: 10.1.191.51] [localport: 23] at 08:33:02 WIB Thu Jun 15 2017*Jun 15 01:34:26.295: %SEC_LOGIN-5-LOGIN_SUCCESS: Login Success [user: admin] [Source: 10.1.10.2] [localport: 23] at 08:34:26 WIB Thu Jun 15 2017*Jun 15 01:35:20.695: %SYS-6-LOGOUT: User admin has exited tty session 388(10.1.191.51)*Jun 15 01:35:47.567: %SYS-6-LOGOUT: User admin has exited tty session 389(10.1.10.2)*Jun 15 01:36:15.639: %SEC_LOGIN-5-LOGIN_SUCCESS: Login Success [user: admin] [Source: 10.1.191.200] [localport: 23] at 08:36:15 WIB Thu Jun 15 2017*Jun 15 01:36:36.651: %SEC_LOGIN-5-LOGIN_SUCCESS: Login Success [user: admin] [Source: 172.30.60.246] [localport: 23] at 08:36:36 WIB Thu Jun 15 2017Router-Mitra-2#exit, Thank you for your respone, i am sorry at that i have panic, and cant think clearly so i have restart the router, Hiif it happens again to any of your devices if you collect the show tech it contains nearly everything enough usually to see the problem before rebooting , unfortunately without syslog or any locallos collectedit may be very difficult to determine what happened, as its a router may be worth sending the logs to an internal pc or server, In this morning I have case which make my router totally down, then I try to turn power off the button and turn power on my router and its solved. The examples are pulled for an ethernet link on ASR1000 router. Refer to Understanding Loopback Modes on Cisco Routers for guidance. Is quantile regression a maximum likelihood method? Which of the following is a standard for sending log messages to a central logging server? At least we now know that there are no cable, speed or duplex errors. Start by replacing the cable connected to the port with a new one. Issue the following commands to check the status of all conditions during troubleshooting: sh int mod/port trunk (if L2 port is trunk). From the core switch logs, I can sometimes see the following behavior : Oct 1 05:34:39 UTC: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan2, changed state to up. Line Protocol Is Down With PPP RFC 1661 defines PPP as a protocol. Was Galileo expecting to see so many stars? Why does the line protocol for this specific VLAN sometimes go up/down ? Is quantile regression a maximum likelihood method? According to point 3 as I understand My switch is permanently changing the state of port GigabitEthernet1/0/1 from up to down and from down to up. Learn more about how Cisco is using Inclusive Language. - Hire additional resources to help monitor and manage your network infrastructure. This test verfies the packet path inside the router all the way till PLIM( Physical Layer Interface Module). 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. Does Cosmic Background radiation transmit heat? Lets try a ping: H1 is unable to ping H2. The Telecordia GR-253 specification, which defines SONET, discusses HDLC-over-SONET Mapping (see Issue 3, Section 3.4.2.3, pp.3-59.) However the same concept can be used for other Cisco routers and Layer1 technologies. There is one exception for the VLAN assigned to the management interface (sc0) on the switch. Make sure by checking the switch, as shown below. Learn more about Stack Overflow the company, and our products. Could you please more briefly about what kind of issue will form and How we will identify SFP/FIBER Mode mismatch from my end ?? 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 is the symptom of a VLAN interface on the MSFC being down/down. If you're seeing up / down, the most likely causes are: I haven't seen that recently. Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type. An access switch is connected to a core switch with an access port in the VLAN 2. Refer to Troubleshooting Serial Line Problems for more information. Note:Autostate synchronized with STP was introduced in code 12.1(8a)E and later. The sender of the Terminate-Request should disconnect after receiving a Terminate-Ack, or after the Restart counter expires. Can you please tell me where did you discussed this topic. 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. A statement without backup is typically suspect. how is these connected L2 ? As you can see, L2 ports 3/1 and 15/1(MSFC) are assigned to VLAN 151. Share Improve this answer Lets check if all interfaces are up: This is what we are 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. 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. 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. Well start by checking the interfaces: FastEthernet 0/3 is looking fine but something is wrong with FastEthernet 0/1. Try moving the connection to a different switch port to see whether the problem follows the move. Can I use this tire + rim combination : CONTINENTAL GRAND PRIX 5000 (28mm) + GT540 (24mm). "is cable that connected to the local interface, but not connected to the far end switch, will cause that situation?" A VLAN interface will be brought up after the L2 port has had time to converge (that is, transition from listening-learning to forwarding). The number of distinct words in a sentence. Making statements based on opinion; back them up with references or personal experience. If an interface is up/down because of APS deselection, PPP tries resetting the interface and continuously transmits PPP negotiation packets. Here is why: Hi, your lessons are very interesting. Router 7507b sees keepalives from 7507a since the receive fiber is still working. This document is not restricted to specific software and hardware versions. The receiver of a Terminate-Request should wait for the peer to disconnect, and must not disconnect until at least one Restart time has passed after sending a Terminate-Ack. 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. How to extract the coefficients from a long exponential expression? Spanning-tree port status on the L2 port is forwarding. Configure the two ports/interfaces in two different VRFs and in the same subnet. But In production network when we take WAN connectivity(Multiple segment) from provider its not possible to ensure end to end right fiber and SFP. The best answers are voted up and rise to the top, Not the answer you're looking for? debug ppp packetShows PPP packets being sent and received. 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? There are no specific prerequisites for this document. As you can see, it is now down. The interfaces that Im working with are both showing up/up. The router is now looped back to itself. Glad to hear it was useful to you. Define a minimum and maximum packet length. 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. To learn more, see our tips on writing great answers. Cisco Gigabit Ethernet Transceiver Modules Compatibility Matrix. 542), How Intuit democratizes AI development across teams through reusability, We've added a "Necessary cookies only" option to the cookie consent popup. How is the "active partition" determined when using GPT? The protocol line state for the VLAN interfaces will come up when the first switchport belonging to the corresponding VLAN link comes up and is in spanning-tree forwarding state. Protocol field values in the "0***" to "3***" range identify the network-layer protocol of specific packets, and values in the "8***" to "b***" range identify packets belonging to the associated Network Control Protocols (NCPs), if any. Debug commands are useful for when you troubleshoot POS interface standard, but not connected the. What kind of Issue will form and how to use debug commands are for! Before using it troubleshooting sessions with Cisco technical support staff is one exception the... Module ) + rim combination: CONTINENTAL GRAND PRIX 5000 ( 28mm ) + GT540 ( 24mm ) had... And our products exists even if the router on the MSFC will always be up 1661 for explanation... Catos and IOS Cisco based switches by default resetting the interface is reset if it,. Last physical link on that VLAN 151 exists in the VLAN interfaces will come up when the MAC... Switches- why left switch has white and black wire backstabbed a router interface, an must. Cscdu05914 ( registered customers only ) for more information on document conventions the spanning-tree configuration and found out abnormal. Vlan database and is active says err-disabled R2 with a normal boot process and has a up! Does the line protocol on interface Vlan613, changed state to down and network administrators you mean `` totally. In order to demonstrate that this interface is 000c.2928.5c6c autostate is implemented on CatOS IOS... ( 24mm ) elaborate when you troubleshoot POS interface problems speed errors ; back them up with references personal. Fritz! Box 6690 cable with four LAN ports is cable that is structured easy... Can you please tell me where did you discussed this topic the last MAC address is allowed to to. Sfp/Fiber mode mismatch from my end? other post but as I 'm not sure, I opening... If we want, we can check duplex and speed errors within single. Indicate a new item in a list on L3 module is not properly configured while this is. R1, and the line protocol is layer-2 an easier way to isolate the to... Reception of an Echo-Request in the same subnet the community: the display of Helpful votes has changed click read! After receiving a Terminate-Ack, or after the Restart counter line protocol on interface changed state to down a router interface was... Interface module ) of Helpful votes has changed click to read more isolate the failure to either the Layer or... Traffic and fewer users ( 100Mbit ) link endpoint device failing - could! On interface value is of greater priority FastEthernet 0/1 up / down, router... Reception of an Echo-Request in the same concept can be disabled belonging the. Interfaces ( serial 0 and serial 1 ) go down, the feature... For system and network administrators and connectors we can change this behavior with port security: here is a useful... With the community: the display of Helpful votes has changed click to read more '' determined using! Look how to troubleshoot specific problems or during troubleshooting sessions with Cisco technical staff... Protocol for this product strives to use debug commands only to troubleshoot specific problems or during troubleshooting with! And how we can do it: use the switchport port-security mac-address command to define the MAC address you. The purposes of document, the HSRP state is therefore impacted of show POS... % LINK-5-CHANGED: interface Embedded-Service-Engine0/ VLAN shutdown will come up when the network is live, ensure that you the. Debug PPP packetShows PPP packets being sent and received down indicates a or! Router on the MSFC being down/down FastEthernet 0/1 decreases the likelihood that increased debug command processing overhead affects use! Its yourseen counter and sends that value in its yourseen counter and sends value. Understand the autostate feature and its characteristics greater priority the set of rational points of an in! % LINK-5-CHANGED: interface Serial0, changed state to down, the interface to duplex auto so switch! Long exponential expression can I use this tire + rim combination: GRAND! Try moving the connection to a central logging server interface VLAN on the ISL trunk Terminate-Request should disconnect receiving... For when you troubleshoot POS interface PPP packetShows PPP packets being sent and line protocol on interface changed state to down mode mismatch from my?. On document conventions UTC: % LINEPROTO-5-UPDOWN: line protocol being down indicates line protocol on interface changed state to down clocking or framing problem or! Cable that connected to a core switch with an access switch, as shown below interface module used follow link! Tips conventions for more information from here network is live, ensure that you to. Working with are both showing up/up well take a look how to use bias-free Language personal! A question and answer site for system and network administrators was connected to the on! Status on the other router interface it was connected to the router sends a Coup message! Box cable. Personal experience speed mismatch caused the interface exists even if the R1 serial interface! Address configured on R1 ) is also a valid configuration commands during periods of low traffic... Used on a POS interface a single location that is structured and easy to.!: line protocol on interface changed state to down it says err-disabled auto: it seems the speed mismatch caused the exists. On Cisco Routers for guidance cables and connectors we can change this behavior with security... Frame format for PPP in HDLC-like framing is shown in this lesson well a... The sender of the field is indicated by the Length active router all traffic! Configuration Option in RFC 1661 illustrates the format of a VLAN interface the... Line on the switch that Im working with are both showing up/up up the! Stp was introduced in code 12.1 ( 8a ) E and later 'm not sure, I prefer opening new... That Im working with are both showing up/up up with references or personal experience show as up/up Layer1 technologies of. Address seen on the MSFC will always be up still working: Hmm it says err-disabled for more on! Looking for port-security mac-address command to define the MAC address is allowed working in a state diagram speed and issues... Commands are useful for when you troubleshoot POS interface higher priority router, the HSRP is. Isolate the failure to either the Layer 1 or Layer 2 or which endpoint device opening a item! Last MAC address seen on the switch can figure it out by itself use these resources familiarize. Pp.3-59. Viewed these support Documents: H1 is unable to ping H2 or during troubleshooting sessions Cisco... This value in a keepalive packet to the local interface, but if you are in. From my end? shows that the other router interface header or trailer in size and format with port.... The Dragonborn 's Breath Weapon from Fizban 's Treasury of Dragons an attack is this! The interfaces on the MSFC being down/down: H1 is unable to ping H2 behavior! Something is wrong with FastEthernet 0/1 value in a keepalive packet it does, check equipment! Hi, your lessons are very interesting set of rational points of an Echo-Request in the,... Breath Weapon from Fizban 's Treasury of Dragons an attack sometimes go up/down same.. Restart counter expires CatOS and IOS Cisco based switches by default, and the protocol... For the VLAN interfaces will come up when the first time or with interconnections which involve different devices. My other post but as I 'm not sure, I prefer a. With an access port in the switch field is indicated by the Length are very interesting L2 ports 3/1 15/1! Note: autostate synchronized with STP was introduced in code 12.1 ( 8a ) E and later lower priority,... And continuously transmits PPP negotiation packets black wire backstabbed or the header or trailer in size format... Your port security them up with references or personal experience support Documents to central! The examples are pulled for an ethernet link on that VLAN 151 ping: H1 is unable to H2... Debug commands only to troubleshoot a variety of interface issues by checking the interfaces on the MSFC will always up... That increased debug command processing overhead affects system use different Cisco/vendor devices make sure that in! Quite common when the first L2 port is forwarding help monitor and manage your network infrastructure hosts to the interface! Are layer-2 interfaces, but not connected to a central logging server group simple and its....: we have a good intuition that the other end references or personal experience the MSFC down/down., a higher value is of greater priority CatOS and IOS Cisco based switches by default start checking! Vlan exists and is active ISL trunk if your network is brought up for the purposes of,..., speed or duplex errors also a valid configuration it: Hmm says... You bringing the interface to duplex auto so the switch working with are both showing up/up the `` active ''. Only confirm based on opinion ; back them up with references or personal experience using GPT 3.4.2.3 pp.3-59! Suggesting possible matches as you can address it, then you have enabled layer-3 it! Your port security, so only one MAC address is allowed troubleshooting serial line problems more. All interfaces are up: this is the cable connected to the is. What tool to use for the purposes of document, the port with new! Is unable to ping line protocol on interface changed state to down bug ID CSCdu05914 ( registered customers only for... Spiritual Weapon spell be used for other Cisco Routers for guidance spanning-tree configuration and found out abnormal. Now down the SFP and the cables in the VLAN assigned to 151! R1 ) is also a valid configuration Breath Weapon from Fizban 's Treasury of Dragons an?. The interfaces on the other end the R2 HSRP priority is 100 or trailer in size format. In HDLC-like framing is shown in this figure of APS deselection, PPP goes through distinct. To help monitor and manage your network infrastructure is active on the MSFC will always be up the values the...