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). On some CatOS platforms, this feature can be disabled in order to allow redundancy in special scenarios. 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. If they are not, a possible timing problem exists on the interface card or in the network. You need to verify spanning-tree port status on the L2 port (should be forwarding). Interface link parameters must match at both ends of the link. 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. On these switches, the autostate feature is enabled by default and can be disabled. Whats the first thing we should check? Transport IP packets and provide a method for receivers to determine the precise type of packet inside the arriving frame. VLAN trunking between Juniper EX -> Cisco Catalyst -> and Cisco Router. Side A would be admin down, and side B would be down/down. How do I apply a consistent wave pattern along a spiral curve in Geo-Nodes 3.3? The end of the field is indicated by the Length. 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. Use the switchport port-security mac-address command to define the MAC address that you want to allow. You need to investigate why this line protocol is not up. Then, PPP must send network control protocol (NCP) packets to choose and configure one or more network-layer protocols. Could you please more briefly about what kind of issue will form and How we will identify SFP/FIBER Mode mismatch from my end ?? POS interfaces support multiple encapsulations - HDLC, PPP and Frame Relay. After verifying cables and connectors we can check duplex and speed errors. Find answers to your questions by entering keywords or phrases in the Search bar above. Standby Preempt and Standby Track Configuration. 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. Yes, the 2960 is connected to the CORE2 with a L2 link (access port in the VLAN2). 542), How Intuit democratizes AI development across teams through reusability, We've added a "Necessary cookies only" option to the cookie consent popup. Was Galileo expecting to see so many stars? I found the problem! Lets try another ping (maybe we get lucky): Too bad, the ping is not working. Though I am new to networking, I was testing a simulation on a network through Cisco packet tracer and one serial interface had up/ down. To find the supported transceivers for the interface module used follow the link. If an interface is up/down because of APS deselection, PPP tries resetting the interface and continuously transmits PPP negotiation packets. How can I explain to my manager that a project he wishes to undertake cannot be performed by the team? 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. So I have a good intuition that the issues comes from here. 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. rev2023.3.1.43268. The interfaces that Im working with are both showing up/up. This could indicate a layer 1 problem like a broken cable, wrong cable (crossover instead of straight-through) or maybe a bad NIC. When one side is unplugged, both LEDs go green. Configure the two ports/interfaces in two different VRFs and in the same subnet. Click here for a complete list of PPP protocol field values . 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 ?? Glad to hear it was useful to you. Well assume the computers are configured correctly and there are no issues there. 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. The frame format for PPP in HDLC-like framing is shown in this figure. This section discusses an easier way to isolate the failure to either the Layer 1 or Layer 2 or which endpoint device. Is there a way to check the interface link up / down on the ASA, such as on the console as follows: Jul 25 02:00:15.268: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/1, changed state to up Jul 25 02:00:17.903: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/1, changed state to down Jul 25 02:00:18.903: %LINK-3-UPDOWN: Interface GigabitEthernet1/0/1 . CN router also shows the interface going up/down when disconnected and reconnected It might be easier if the interface could recover itself after a certain time. *Jan 2 00:00:04.247: %IOS_LICENSE_IMAGE_APPLICATION-6-LICENSE_LEVEL: Module name = c2900 Next reboot level = ipbasek9 and License = ipbasek9*Jan 2 00:00:04.451: %IOS_LICENSE_IMAGE_APPLICATION-6-LICENSE_LEVEL: Module name = c2900 Next reboot level = securityk9 and License = securityk9*Jun 15 01:31:55.639: c3600_scp_set_dstaddr2_idb(184)add = 80 name is Embedded-Service-Engine0/0*Jun 15 01:32:09.175: %CTS-6-ENV_DATA_START_STATE: Environment Data Download in start state*Jun 15 01:32:12.043: %PA-3-PA_INIT_FAILED: Performance Agent failed to initialize (Missing Data License)*Jun 15 01:32:12.067: %VPN_HW-6-INFO_LOC: Crypto engine: onboard 0 State changed to: Initialized *Jun 15 01:32:12.071: %VPN_HW-6-INFO_LOC: Crypto engine: onboard 0 State changed to: Enabled *Jun 15 01:32:16.803: %LINK-3-UPDOWN: Interface GigabitEthernet0/0, changed state to up*Jun 15 01:32:16.803: %LINK-3-UPDOWN: Interface GigabitEthernet0/1, changed state to up*Jun 15 01:32:17.619: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan1, changed state to down*Jun 15 01:32:17.851: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0, changed state to up*Jun 15 01:32:17.851: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/1, changed state to up*Jun 15 01:32:18.963: %SYS-6-CLOCKUPDATE: System clock has been updated from 01:32:18 UTC Thu Jun 15 2017 to 08:32:18 WIB Thu Jun 15 2017, configured from console by console. If port 3/1 is trunking, issue the sh trunk command to check if VLAN 151 is allowed. High latency/drops between Cisco switches in two locations. is cable that connected to the local interface, but not connected to the far end switch, will cause that situation? 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). Other than quotes and umlaut, does " mean anything special? No, it is point-to-point at layer-3. Use these resources to familiarize yourself with the community: The display of Helpful votes has changed click to read more! Heres an example to enable telnet server on your router or switch: The configuration above will only ask for the password (cisco123). Hi Rene, thanks for the lessons. This phrase has several connotation. You can use this to only allow specific MAC addresses. 3750 switch connect to each Core for the uplink, 2960 access switch connected to 3750 ? To sugget better, we would like to see your configuraiton and topology ? If the problem persists, check other hardware components. According to point 3 as I understand Ask a question or join the discussion by visiting our Community Forum, Get Full Access to our 758 Cisco Lessons Now, Last Source Address:Vlan : 0090.cc0e.5023:1, FastEthernet0/1 is down, line protocol is down (err-disabled), 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. Server Fault is a question and answer site for system and network administrators. Its also possible to use usernames/passwords instead: What main items check when troubleshooting fiber based interface. When R1 and R2 exchange HSRP hellos, R2 learns the standby IP address from R1. Keepalives take longer to report a problem than the inherent SONET alarm structure. 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. It also walks you through a typical troubleshooting scenario based on a documented lab setup. How is "He who Remains" different from "Kang the Conqueror"? Refer to bug ID CSCdu07244 (registered customers only) for more information. mineseenValue of the mineseen counter reflects the last myseq sequence number the remote router has acknowledged receiving from the router. Alternatively, you can post and accept your own answer. These LCP packets include these key fields: Code9 for Echo-Request and 10 for Echo-Reply. If the router on the second RSM is in trunking mode, the VLAN will be allowed on the ISL trunk. Thanks for contributing an answer to Server Fault! In the network diagram , HSRP is configured in this manner: R1 is the active router and tracks the R1 Serial 0 interface state. Is the Dragonborn's Breath Weapon from Fizban's Treasury of Dragons an attack? 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. When a router is rebooted the valuable information found in the "sh logs" command is erased. 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. When you finish using a debug command, remember to disable it with its specific no debug command or with the no debug all command. 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. 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 . How is the "active partition" determined when using GPT? The last MAC address seen on the interface is 000c.2928.5c6c. This document discusses why this happens, and how the L3 and L2 interfaces interact with each other in the control plane after being activated. What are some tools or methods I can purchase to trace a water leak? *Mar 1 01:54:39.699: %LINEPROTO-5-UPDOWN: Line protocol on Interface Tunnel0, changed state to up. Are these the complete logs from the router. - edited Can you post the configuration and spanning-tree config ? Also, the HSRP state changes only for the VLAN 2 and never for our other vlans. Perform a local loop test first, and then a remote test. There also are various vendor-specific values. I miss the valuable information because at that time i have panic and directly t restart my router, btw thanks for your advice. 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 is sample output from the debug serial interface command for an HDLC connection when keepalives are received properly by both ends. Lets try a ping: H1 is unable to ping H2. This change makes the R2 priority of 100 higher. Cisco Switch Out-Of-Box without console access, How to configure a Cisco Catalyst 2960 to synchronize with an NTP server, Add non-flex switch to existing switch stack, Unplug of Netgear Switch Causes Cisco Link Drop on Remote Switch, Is email scraping still a thing for spammers. Lets try a ping: Unfortunately our pings are not working. Here is why: Hi, your lessons are very interesting. One of these is for a 2.5Gbps link that the switch was plugged into. Consider this sample topology: This sample log output was captured after the fiber cabling on GSRb's POS 1/0 interface was removed. The autostate feature is not synchronized with the STP state. When the difference in the values in the myseq and mineseen fields exceeds three, the line goes down and the interface is reset. The state of R1 is active and the state of R2 is standby. You need to investigate why this line protocol is not up. 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. 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 shows an example that uses the standby preempt command in conjunction with the standby track command. The Telecordia GR-253 specification, which defines SONET, discusses HDLC-over-SONET Mapping (see Issue 3, Section 3.4.2.3, pp.3-59.) This test excludes the SFP and the cables in the packet path. Check to make sure that VLAN 151 exists in the VLAN database and is active. This table lists the three classes of LCP packets: LCP is used to establish the connection through an exchange of Configure packets. POS interfaces support PPP in High-Level Data Link Control (HDLC)-like framing, as specified in RFC 1662 , for data encapsulation at Layer 2. Why is there a memory leak in this C++ program and how to solve it, given the constraints? We have a security violation, and as a result, the port goes in err-disable state. 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. 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. 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
