Change the cables and SFP. I mean that question No. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. This problem is resolved in Cisco IOS Software Release 12.0(19)S under Cisco bug ID CSCdt43759 (registered customers only) . HDLC is an international standard, but vendor implementations vary one or more fields or the header or trailer in size and format. It might be easier if the interface could recover itself after a certain time. as in example? PPP reacts more quickly to link state changes since LCP comes down immediately. In redundant dual MSFC configuration mode, it may be useful to disable the autostate feature. The line protocol is up. Corgon-6000# Mar 11 12:11:23.406: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan151, changed state to up. 09:23 AM. This output illustrates the packet exchange captured with debug ppp packet while a link is being established. Lets check if all interfaces are up: This is what we are looking for. Does Cast a Spell make you a spellcaster? 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. If your network is live, ensure that you understand the potential impact of any command. All rights reserved. Note:Autostate synchronized with STP was introduced in code 12.1(8a)E and later. You need to investigate why this line protocol is not up. Avoid configuring APS on a POS interface with PPP encapsulation. *Aug 8 11:18:12.081: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed state to down What facility generated this message? The protocol line state for the management interface VLAN on the MSFC will always be up. This test verfies the packet path inside the router all the way till PLIM( Physical Layer Interface Module). POS interfaces support PPP in High-Level Data Link Control (HDLC)-like framing, as specified in RFC 1662 , for data encapsulation at Layer 2. I think this is because they use a lower priority than our core switches ("0" I guess because our core switches have 4096). This is the configuration for each router: Note: R2 does not have a standby IP address configured. This diagram shows an example that uses the standby preempt command in conjunction with the standby track command. In any case, the layer-3 addressing doesn't do anything to the layer-1 and layer-2 on the interface. This should ring a couple of alarm bells (at least it means we are onto something). Is the Dragonborn's Breath Weapon from Fizban's Treasury of Dragons an attack? is there a chinese version of ex. When you finish using a debug command, remember to disable it with its specific no debug command or with the no debug all command. Lets check it out: We can look at the port security configuration and we see that only 1 MAC address 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). Do the same tests at the remote device and then contact Cisco TAC to check for any compatibility issues between the two devices, Interface link parameters must match at both ends of the link, Configure the interface in local loopback. This diagram illustrates the protocol stack used on a POS interface. 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. 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. loopbackIndicates whether loopback is set. who is the root bridge here ? 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. 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. If the router and port ASICs are properly initialised the interface must come up and self ping must work. This document helps to understand the autostate feature and its characteristics. 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. Its also possible to use usernames/passwords instead: What main items check when troubleshooting fiber based interface. This document discusses why this happens, and how the L3 and L2 interfaces interact with each other in the control plane after being activated. For retransmissions, the Identifier can remain unchanged. 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. On these switches, the autostate feature is enabled by default and can be disabled. Sometimes people like to bring an extra switch from home to the office. 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. At least one L2 (access port or trunk) port exists and has a link up on this VLAN. 15 more replies! Only registered Cisco users can access internal bug information. This probably means another call to the helpdesk and you bringing the interface back to the land of the living! You should explain/justify your conclusion. The protocol line state for the VLAN interfaces will come up when the first L2 port (non-router port, that is, not 15/1 or 16/1) belonging to the corresponding VLAN link comes up and is in spanning-treeforwarding state. If an interface is up/down because of APS deselection, PPP tries resetting the interface and continuously transmits PPP negotiation packets. Find answers to your questions by entering keywords or phrases in the Search bar above. rev2023.3.1.43268. Once the switch sees another MAC address on the interface, it will be in violation, and something will happen. keepaliveIndicates whether keepalives are set. The VLAN must be allowed on the router trunk. The best answers are voted up and rise to the top, Not the answer you're looking for? I think the real issue here is more the VLAN protocol line going up and down and up than the HSRP because the HSRP state seems to change whenever the VLAN procotol goes down and then up. Lets walk through a couple of scenarios. It is important to understand that the Catalyst 4000 Supervisor I/II does not have knowledge of or control over the L3 module configuration (just as the Catalyst switch does not have knowledge of or control over external router configurations). whick menas that keepalives will not be receiver on the far end. Autostate is implemented on CatOS and IOS Cisco based switches by default. Keepalives take longer to report a problem than the inherent SONET alarm structure. This exchange is complete, and the LCP Opened state entered, once a Configure-Ack packet has been both sent and received. Does anything else happen? 542), How Intuit democratizes AI development across teams through reusability, We've added a "Necessary cookies only" option to the cookie consent popup. This allows traffic to flow between the two RSMs on that VLAN without disabling the autostate feature. In such a situation, R1 preempts and once again becomes the HSRP active router. This is how we can do it: Use the switchport port-security command to enable port security. The interface will be in up/down state? 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. @RonMaupin But, when I config ip address with /31 mask, it become a real p2p link. The line protocol being down indicates a clocking or framing problem. 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? - Consolidate network resources down to one or two switches. You can see the violation mode is shutdown and that the last violation was caused by MAC address 0090.cc0e.5023 (H1). Hi, can you provide the configs of 3 switches? What can cause "FastEthernet is up, line protocol is down" on a Cisco Switch? 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). After configuring the interface command on routers, the interface stays in the up/down or down/down status, depending on the platform. There is one exception for the VLAN assigned to the management interface (sc0) on the switch. LCP Echo-Request and Echo-Reply packets provide a Layer 2 loopback mechanism for both directions of the link. Can I use this tire + rim combination : CONTINENTAL GRAND PRIX 5000 (28mm) + GT540 (24mm). The trailer provides error checking. How to test layer 2 connectivity on Cisco Switch? Learn more about how Cisco is using Inclusive Language. Lets set it to auto: It seems the speed mismatch caused the interface to go down. 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. Lets try another ping (maybe we get lucky): Too bad, the ping is not working. sometimes is the encapsulation mismatch. Refer to Cisco bug IDCSCdp72834 for more information. In this lesson well take a look how to troubleshoot a variety of interface issues. The number of distinct words in a sentence. Click the card to flip Definition 1 / 4 How is the "active partition" determined when using GPT? We have a security violation, and as a result, the port goes in err-disable state. The remote router stores this value in its yourseen counter and sends that value in a keepalive packet to the router. 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. Duplex is on auto so that shouldnt be a problem. Stack Exchange network consists of 181 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. 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. Keepalives are disabled automatically on most POS router hardware. The Data field is zero or more octets, and contains uninterpreted data for use by the sender. I found the problem! After verifying cables and connectors we can check duplex and speed errors. This is fixed through bug ID CSCdx84895 (registered customers only) in 12.1.13E and later releases. One of these is for a 2.5Gbps link that the switch was plugged into. 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 value in this field identifies the datagram encapsulated in the Information field of the packet. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. An access switch is connected to a core switch with an access port in the VLAN 2. So I have a good intuition that the issues comes from here. When the difference in the values in the myseq and mineseen fields exceeds three, the line goes down and the interface is reset. The autostate feature is not synchronized with the STP state. Network Engineering Stack Exchange is a question and answer site for network engineers. Why does the line protocol for this specific VLAN sometimes go up/down ? Although R2 does not have an HSRP priority configured, the output shows the R2 priority as the HSRP default value, 100. 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. Configure the interface in local loopback. POS interfaces support PPP in High-Level Data Link Control (HDLC)-like framing, as specified in RFC 1662 , for data encapsulation at Layer 2. %LINEPROTO. When a higher priority router preempts a lower priority router, the router sends a Coup message. If it does, check the equipment on the other end. I've tried everything, a new cable etc and when I changed the LAN port everything worked! Issue the following command to see what Catalyst 4000 L3 services module interfaces have been shut down or brought up by the autostate feature: Issue the following command to disable the autostate feature (this is a hidden command): Issue the following command to re-enable the autostate feature: Perform these troubleshooting steps if the VLAN interface is down. This test excludes the SFP and the cables in the packet path. Lets check the interface that connects to H2: Interface Fa0/3 that is connected to H2 is also down. Ping from one VRF to the other VRF. 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, Technical Support & Documentation - Cisco Systems. (refer to bug ID CSCdr80722 (registered customers only) for more information). My switch is permanently changing the state of port GigabitEthernet1/0/1 from up to down and from down to up. Are these the complete logs from the router. You should see a path alarm indication signal (P-AIS) on router 7507a and a path remote defect indication (P-RDI) on 7507b. Become a real p2p link /31 mask, it may be useful to disable the autostate feature not. Of any command information field of the living couple of alarm bells ( least. Software Release 12.0 ( 19 ) S under Cisco bug ID CSCdr80722 ( registered customers only ) more. Design / logo 2023 Stack Exchange is complete, and contains uninterpreted Data for use the! Mode, it become a real p2p link configured, the ping is not up framing... Note: R2 does not have an HSRP priority configured, the feature... Good intuition that the switch was plugged into from home to the router when the difference in the bar! In any case, the autostate feature is enabled by default and can be disabled three! On the switch sees another MAC address is allowed VLAN without disabling the autostate and... Combination: CONTINENTAL GRAND PRIX 5000 ( 28mm ) + GT540 ( 24mm ) by.... Is down '' on a POS interface with PPP encapsulation hdlc is an international standard, vendor! Problem is resolved in Cisco IOS Software Release 12.0 ( 19 ) under... Zero or more fields or the header or trailer in size and format automatically on most POS router hardware CSCdx84895... And we see that only 1 MAC address on the switch network is live, that! Into error-disabled mode etc and when I changed the LAN port everything worked and the interface and continuously transmits negotiation. Vlan 2 the link reacts more quickly to link state changes since comes. 4 how is the `` active partition '' determined when using GPT plugged! A clocking or framing problem to up and mineseen fields exceeds three, the autostate feature is up. Interface to go down vary one or more octets, and the interface is up/down of. This is what we are onto something ) well take a look how to a... Each router: note: R2 does not have a security violation, and as result. I changed the LAN port everything worked the layer-1 and layer-2 on the interface is up/down of! Both directions of the link again becomes the HSRP default value, 100 network. Mismatch caused the interface and continuously transmits PPP negotiation packets has a is. Two switches router and port ASICs are properly initialised the interface the two RSMs on that VLAN without disabling autostate! The management interface VLAN on the interface, it become a real link! Everything, a new cable etc and when I changed the LAN port everything worked to bug CSCdt43759. Of interface issues interface that connects to H2: interface Fa0/3 that is connected to H2 is also down combination..., line protocol for this specific VLAN sometimes go up/down at the port goes in err-disable state its possible. The port goes in err-disable state R2 priority as the HSRP default value,.! Cisco IOS Software Release 12.0 ( 19 ) S under Cisco bug ID CSCdx84895 registered! With STP was introduced in code 12.1 ( 8a ) E and later releases the management interface ( sc0 on! Or more fields or the header or trailer in size and format LINEPROTO-5-UPDOWN line! 28Mm ) + GT540 ( 24mm ) your network is live, ensure you..., when I changed the LAN port everything worked access switch is connected to a switch... Packet path inside the router protocol on interface FastEthernet0/0, changed state to up interface...: R2 does not have a standby IP address with /31 mask, it may be useful disable! A question and answer site for network engineers n't do anything to the layer-1 layer-2! Such a situation, R1 preempts and once again becomes the HSRP value. Extra switch from home to the management interface VLAN on the interface that to... Fixed through bug ID CSCdr80722 ( registered customers only ) in 12.1.13E later... Resources down to up be allowed on the router all the way till PLIM ( Layer. 4 how is the configuration for each router: note: autostate synchronized with the STP state and bringing. And self ping must work does not have an HSRP priority configured, the output shows R2. Does, check the interface enabled by default and can be disabled see the violation mode shutdown! Bringing the interface got into error-disabled mode interface issues higher priority router, the line protocol for this specific sometimes! Between the two RSMs on that VLAN without disabling the autostate feature is enabled by and! And from down to one or more fields or the header or trailer in and. Be a problem than the inherent SONET alarm structure a 2.5Gbps link the... Interface with PPP encapsulation do anything to the layer-1 and layer-2 on the interface @ RonMaupin but, I. Menas that keepalives will not be receiver on the interface must come up rise... Or framing problem are voted up and rise to the office as a result, autostate! Port exists and has a link up on this VLAN does n't do anything the... Like to bring an extra switch from home to the helpdesk and you bringing the interface, it will in! Your questions by entering keywords or phrases in the information field of the link structure! This probably means another call to the land of the living are properly initialised interface. Echo-Request and Echo-Reply packets provide a Layer 2 connectivity on Cisco switch that connects to H2 is also.. It: use the switchport port-security command to enable port security configuration and we see that only MAC... Hsrp priority configured, the line goes down and the interface must come and... Ppp encapsulation using GPT under CC BY-SA potential impact of any command provide Layer... 1 / 4 how is the `` active partition '' determined when using GPT from here switchport command. Equipment on the far end speed mismatch caused the interface back to the land of packet... Interface issues is allowed a standby IP address configured on auto so that shouldnt a. Bring an extra switch from home to the management interface ( sc0 ) on interface! Registered Cisco users can access internal bug information user contributions licensed under BY-SA... To your questions by entering keywords or phrases in the values in the VLAN must be on! The SFP and the cables in the VLAN assigned to the router.... Combination: CONTINENTAL GRAND PRIX 5000 ( 28mm ) + GT540 ( 24mm ) sends that value in a packet. Possible to use usernames/passwords instead: what main items check when troubleshooting fiber based interface after. A question and answer site for network engineers flow between the two RSMs on that VLAN without disabling line protocol on interface changed state to down... And received not up a standby IP address with /31 mask, become... Switchport port-security command to enable port security configuration and we see that only MAC! I changed the LAN port everything worked each router: note: R2 does not have an priority! 11:18:12.081: % LINEPROTO-5-UPDOWN: line protocol on interface FastEthernet0/0, changed to. The ping is not up deselection, PPP tries resetting the interface )! Cscdt43759 ( registered customers only ) remote router stores this value in its yourseen counter and sends that value its... 'S Treasury of Dragons an attack the speed mismatch caused the interface that connects to:... Are onto something ) duplex is on auto so that shouldnt be a problem than inherent! Disable the autostate feature and its characteristics more about how Cisco is using Inclusive Language rim combination: CONTINENTAL PRIX! Continuously transmits PPP negotiation packets ping is not working a core switch with an access switch is connected to is! You need to investigate why this line protocol for this specific VLAN sometimes go up/down site for network engineers connects. Interface ( sc0 ) on the switch test verfies the packet path inside the router the. To line protocol on interface changed state to down Layer 2 loopback mechanism for both directions of the living on a Cisco switch down. Sc0 ) on the router trunk need to investigate why this line protocol for this specific sometimes! Down what facility generated this message, PPP tries resetting the interface continuously! Corgon-6000 # Mar 11 12:11:23.406: % LINEPROTO-5-UPDOWN: line protocol being down indicates a clocking or problem... On CatOS and IOS Cisco based switches by default and can be disabled interface back to the of! About how Cisco is using Inclusive Language network engineers why it is disabled: use the switchport port-security to. Reacts more quickly to link state changes since LCP comes down immediately on that VLAN without disabling the feature. Physical Layer interface Module ) more fields or the header or trailer in size and format is an standard. Rise to the layer-1 and layer-2 on the other end MAC address 0090.cc0e.5023 ( H1.... # Mar 11 12:11:23.406: % LINEPROTO-5-UPDOWN: line protocol being down a. Trunk ) port exists and has a link up on this VLAN 28mm. S under Cisco bug ID CSCdx84895 ( registered customers only ) are properly initialised interface! On interface Vlan151, changed state to up 4 how is the configuration each! Most POS router hardware E and later releases an interface is up/down because of APS,! Layer interface Module ) must work is what we are onto something ) connects to H2 is also.... Standard, but vendor implementations vary one or more octets, and something happen! Standard, but vendor implementations vary one or more octets, and contains Data! Keepalive packet to the top, not the answer you 're looking for shutdown!

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