Cisco Switching/Routing :: 3560-X PoE Stuck In Loop On Startup
Feb 17, 2013
I have a Catalyst 3560-X PoE that suddenly stopped working. I plugged in via console and below is the output I received. It scrolls constantly and I am unable to enter ROMMON mode or stop it from scrolling. I've read of a possible problem with the IOS version but I'm unable to verify due to not being able to stop the scrolling.
Switch uptime is 4 minutes, 4 seconds
cisco WS-C3560X-24P (PowerPC405) processor (revision A0) with 262144K bytes of memory.
Processor board ID FDO1522R2AY
I have a couple of 3560 switches running c3560-advipservicesk9-mz.122-44 and they are randomly experiencing the following:
- The switch locks up with no preceding error message in the log (I am forwarding syslog to Splunk).
- Upon reboot, the switch goes through the normal startup sequence with no error messages, then for some reason reloads the flash and starts all over again. (refer to doc)
This could happen after days or weeks. Sometimes they will go through two of these reloads on boot and be fine for awhile, and other times they will be stuck in the loop infinitely. I am using this same image with all of our 3560s, but am only having this issue with two of them.
I am having an issue with this device after setting the ip address and rebooting. I have tried renaming the config.text file without success. I have also tried the steps mentioned here: [URL]
I have a strange issue where spanning-tree is blocking vlans through a mesh network.Here is my set up.
2-Cisco 3560's that have two trunk ports set with do1q and a native vlan of 2. I'm allowing a client vlan (2) and a voice vlan (103) to come over the trunk. They have a native vlan of 2 so the mesh APs can get an address through DHCP. Spanning-tree loop guard is also enabled.
When connected to the mesh network, the voice vlan is being blocked by spanning-tree. I get the following erros:
000129: *Feb 28 19:24:58.289 EST: %SPANTREE-2-LOOPGUARD_BLOCK: Loop guard blocking port FastEthernet0/1 on VLAN0103.000130: *Feb 28 19:24:58.448 EST: %SPANTREE-2-LOOPGUARD_UNBLOCK: Loop guard unblocking port FastEthernet0/1 on VLAN0103.
Eventually the loop is cleared and the port is set back to a forwarding state from a blocking state. I don't want to disabled spanning-tree loopguard since I don't want to create a loop. The mesh network is supposed to act as a P2P connection between two switches. As a test I disconnected the APs from their trunk ports. I then used a cross over cable to connect the switches and no spanning tree loops occured. The mesh doesn't have STP enabled on it and should just be acting as an over-the-air connection from one switch to another.
I just recently upgraded my 3845 to 15.0.1M9 and everything was going fine until I turned it back on later today. It is now stuck in a loop and wont even allow me to access ROMMON. I took out all additional hardware and it is still stuck at this screen. [code]
I've got several 3502i's that refuse to join to the controller, and just get stuck in a cycling blinking colors on the LED. Other AP's off the same port, controller, work fine. Logs are as follows...
*Feb 6 19:40:37.000: %CAPWAP-5-DTLSREQSEND: DTLS connection request sent peer_ip: 10.160.4.7 peer_port: 5246 *Feb 6 19:40:37.000: %CAPWAP-5-CHANGED: CAPWAP changed state to
I have a Cisco 850 router that whas having problems getting an ip address via DHCP. I did some stuff on it but that didn't work, so I rebooted the router to go back to my last saved startup config. When I turned it back on and connected t othe CLI console I got the "Would you like to enter the initial configuration dialogue?" message. Thinikng I just forgot to save anything to the startup config I went through the initial set up again and made sure to save everything to the startup config. After going through the intial config and setting up a vlan to assign DHCP to clients I saved the config and rebooted, upon reboot and connecting to the CLI console I got the same "Would you like to enter the initial configuration dialogue?" message. Tryign the setup once more and making sure everything was saved to startup config I rebooted again just to make sure the changes would stick, and sure enough they didn't. Whay is the config not saving to the startup config?
I have manual Cisco 1812 (1811) Integrated Srvice Router Cabling and Installation in front of meI have Cisco 1811 connected to my laptop according to this manualI have Cisco SDM latest version installed on my laptopI have DHCP enabled on my laptopThe problem that my laptop can't get valid IP adreess from the router (see att. laptop_, laptop_2)
Which IP address I have to use in order to get access to router inrerface (see. SDM_1)?
I messed up the IOS on the flash of CISCO881-SEC-K9. On reboot it booted to ROMMON which allowed me to tftp up a working IOS c880data-universalk9-mz.151-4.M3.bin. Unfortunately somewhere in my playing around the default startup configuration factory loaded on the routerhas been erased. I can load a new a config on the device but as I'm using the router to learn its useful to have the original config load when I factory reset the device. What is the factory start up config?
I am trying to reproduce a Spanning-Tree loop in my lab that occurred on Ops, and for the life of me I cannot break it. The loop is very simple:
Cisco 2960------------FW that doesn't forward STP traffic-----------Cisco 2960
This created an STP loop. In my lab, I am substituting the FW for another Cisco 2960 with STP disabled and BPDUFilter on ingress/egress ports to stop the switch from sending BPDU's to the downstream switch to keep it in the dark, as the FW did on Ops.
I have reconfigured the FEX numbers attached to a Nexus 5548 running on NXOS5.2 If I do show running-config the interfaces are not there anymore. But if I do show startup-config the old Fex interfaces still shows up. I did try write erase then saved the running-config and its still there.
We have a couple of cisco SGE switches connected to a single DELL, between the cisco switches we have a trunk interface. I'm not sure which setting should be configured on the switches to get it working because a loop is occuring.
We recently wanted to swap our existing WS-SUP720-base with a WS-SUP720-3B in a 6513 chassis.Had the existing configuration config saved in a txt file and replaced the supervisor. Booting went fine and we pasted in the original config. There was one failure message about unnsupported command but didnt take further notice."boot system flash sup-bootflash:" was probaly the line that the 720-3B didnt support.After wr mem and reload it went in continious loop and rebooting due to inncorrect boot device. Had to put back the old supervisor and have now the 720-3B in a 6504 chassis. Tried some commands in rommon, but are not getting any further.
I was wondering if I can force catalyst 2960 to skip startup config stored in NVRAM and boot with no config everytime it is powered. I tried to find it on google and in cisco white papers but still no luck. I found only commands that begin with "set boot config-register ... ", but switch acts like it does not know these commands.
I have an 877W router that I would like to have a 2nd pre-configured backup for. I was thinking of getting another 870 series (probably an 877) router, as the more expensive wireless option is not actually required. Am I right to assume that I could simply copy the contents of my current config.txt file onto the second router?
We have recently purchased 2 x 4900M switches with the following configuration:
2 x X2-10GB-SR installed in port te1/1, 1/2 (optical)
1 x 20 x 1GB RJ45 installed in the top left of chasis ge2/1 - 2/20
1 x WS-X4908-10G-RJ45 8 port 1/2 card in the top right of chassis te3/1 - 3/8
We have te1/1 connecting the 2 switches, and various vlan's and connections on the 1GB RJ45's with no problems.
However, we have a number of 10Gbps BaseT connections te3/1 - te3/5 which are causing us issues. On a reload of the switch or removal / re-install of the cable it can take anywhere up to an hour for the port to become active again. So when we reload the switch, we may get a connection come up after say 3 mins, but the port next to it may not come up for 15-60 min. The cabling is all the same (CAT6 and has been tested/verified) and all connections go to Broadcom 10Gb cards in Dell 820 servers running vmware. We have the following set on the ports:
switchport mode access spanning-tree portfast
No speed or duplex can be set on these ports - these options are not available in the config.
Once a link is finally established, it will hold the link solid with no problems, but this is a problem for us, we can't have a reboot take an undetermined amount of time for the link to come back.
I Like To Intentionally Create A Layer 2 Loop in My LabI have 2960 and 3750 switches and servers with multiple NIC's and also Some PC's and Hubs. Connections and Commands And Features Which Sould Be Disabled or Enabled)
we recently had on our network a simple layer 2 loop problem, with big effects.Here is the situation: we have a C3750 switch, with STP activate on all ports.We don't have total control on this switchs, and for some reasons, it is possible that people connect a 2d switch on it (Cisco or non-Cisco).What happened several times is a classic case: a person interconnect 2 ports of this 2d switch, creating a loop. As the loop is created on the 2d switch only, the 1st switch detect no loop, the the uplink port keeps up.Afer this loop created, a broadcast storm occurs through the link between 1st & 2d switch .. and the storm propgates all over the LAN.I try to find some solutions to avoid that. One thing I would like to do is to find a mecanism on the first switch, which can permit to block the uplink port on the 1st switch if it sees the same MAC address as source in the 2 directions.Note that storm control, even configured to a quite low value (ie: 2Mbps) is not efficient enough to protect equipment (we have had big CPU impact on LAN equipments).
I have an Extremely Old switch that I need to connect to my network. Because it is so old I don't want it to become the Root Switch.
what is the command to change the priority. (Honestly I don't remember if it has to be a lower number 1 or a higher number ). Always get that mixed up. I've read about root guard, but I would like to prevent it manually. (It is a small network after all)It is a Cisco 2950.
Do Cisco Catalyst (IOS) and specially Cisco SG300/500 support a similar feature to HP's Loop Protection or DLINK's Loopback Detection? This is an interesting feature to avoid loops caused by unmanaged switches.
I have a bunch of 3750x switches that each have a 10 gig routed link back to a central 4507 (loopback = 172.30.255.255).We carved up a /24 (of course, the /24 doesn't really exist except in our address tracking spreadsheet) into a bunch of /30's for routed WAN links and /32's for loopback addresses.We started on the low end for /30 subnets (ie 172.30.255.0/30, 172.30.255.4/30, etc.).We started at the high end for the /32 loopbacks (ie 172.30.255.255/32, 172.30.255.254/32, etc.)
Well, when I try pinging 172.30.255.255 from the access layer 3750x switches, the 3750x seems to be treating it as a broadcast ping where it lists each member that responds instead of the regular !!!!! response (this makes think something is odd with the 3750x). Of course, only one member responds (the core). But even the core seems to respond with the other end of the /30 instead of the actual /32 loopback (which makes me think something is odd in the core). I could have sworn that I've setup similar topologies without problems (ie, using 10.0.0.0/32, 10.255.255.255/32, etc as loopbacks) and as long as the mask is a /32, it should work.Also, I can ping/ssh to that loopback if my laptop is on a directly connected subnet. But I can't do it from any of the 3750x switches (which are also directly connected).I've double checked for overlapping subnets, but nope. I don't see any. Routing looks fine. The actual /32 is being propagated everywhere properly.
I have a 3925 Router with a 48 port switch module (part number SM-D-ES3G-48-P). I have no problem accessing the 3925 Router, but when I go into the 48 port, I get an error that reads
Error Hardware not supported by firmware. Try loading a newer software instead. System Resetting...
I know that the wrong IOS is installed on the switch, but the problem is that this is an endless loop. The switch resets then comes back to the same error. How to get the switch out of this loop so that I can load the correct IOS.
The following error was seen on the switch and the Diagnostic Test Loop back failed following a new WS-6748-SFP module installation.Fabric in slot 5 detected excessive flow-control on channel 3 (Module 4, fabric connection 1)
Tried Hard reset of the module and still the error persist.
i have recently tried to change the catos on a Catalyst 2948G-L3 and since then i have the following message in a loop :I know that the solution would be to download a new valid image from tftp via the rommon prompt but what i dont undertand is why i cant access the rommon prompt. It justs boots with the message above in a loop
We have a Cisco 3750G Core switch which has physical connections, each configured as trunks to two HP Access switches. The client who uses these access switches would like to put a link between the two, but this would create a loop.
Here is my Lab Setup: 2691 is BGP nei to R4 router and they are not directly connected. 2691 and R4 are in same AS 6500. 2691 Config---router ospf 1 network 3.3.3.3 0.0.0.0 area 0 . Its advertising its loop back IP to OSPF domain.
We can see that 2691 and R4 are BGP neis and 2691 has 200.1.x.x routes in its route table. My question is why from 2691 router i am unable to ping any route learned by BGP from R4?
2691Router# ping 50.1.1.0 Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 50.1.1.0, timeout is 2 seconds:.....Success rate is 0 percent (0/5)2691Router#ping 200.1.2.0 [ code]...
I have just received a new Cisco 3750G Switch from my parent company. When attempting to install the switch, I discovered that it will not boot to CLI, only to the bootloader. After using the command boot, the switch attempts to boot the most current IOS version, but fails, stating "error loading XXXXXXXXXX.bin".
Obviously, I just need to get a functional version of the IOS onto the switch to boot, but the problem is exactly how can I do that? All (or most) the commands with which I am familiar are unavailable in the bootloader, so all methods known to me fail. Is there a simple way (maybe using the copy command?) to put the .tar or .bin file onto the flash?
I am trying to configure a loop back interface like so: [URL], on the following device:
C3550 Software (C3550-IPSERVICESK9-M), Version 12.2(50)SE, RELEASE SOFTWARE (fc1on port gig0/1 which is using a 1000Base-SX adapter. This is for troubleshooting purposes and it does not appear to be a feasible option. Is there another way to accomplish in the IOS?
I have 6509 E. Actually what happen it last 3-4 times it reload its self and got stuck in rommon mode, i tried to boot it with boot by connecting a console cable on supervisor 720 2b. What and where is problem and why is stuck in rommon after reload.
