What packet will switch send when config with keepalive ?

When I config keepalive on switch interface, what will happen ? Is it multicast packet or broadcast packet ?
There is syslog information on my switch which I make loop to test BPDUguard.
"%ETHCNTR-3-LOOP_BACK_DETECTED: Keepalive packet loop-back detected on FastEthernet0/7"
Where can I find detail document about it ?
thanks!

thanks for your reply.
I sniffe it and get following:
ETHER: ----- Ether Header -----
ETHER:
ETHER: Packet 106 arrived at 18:49:46.07
ETHER: Packet size = 60 bytes
ETHER: Destination = 0:3:e3:9b:ad:c0,
ETHER: Source = 0:3:e3:9b:ad:c0,
ETHER: Ethertype = 9000 (Loopback)
ETHER:
Source MAC and DEST mac is same and belong to switch static mac.
I can't understand why my test will result in "ETHCNTR-3-LOOP_BACK_DETECTED: Keepalive packet loop-back detected on FastEthernet XX".
My lab is like this:
switch-----hub(portA,portB),one cable is connected portA and portB of hub. So there is loop on hub.
If I disconnect cable between portA and portB, switch will not report ETHCNTR-3-LOOP_BACK_DETECTED.
It looks like that loop on hub result in the error. But I don't know why ?
Who can tell me detail information ?
thanks!

Similar Messages

  • HT1414 what i will do ?when i tunes talde me We're sorry, we are unable to continue with your activation at this time

    what i will do ?when i tunes talde me We're sorry, we are unable to continue with your activation at this time

    That's almost always because the phone was jailbroken r hacked to unlock it.
    Discussing jailbroken / hacked phones is forbidden by the terms of service. You'll have to find an answer elsewhere or buy a new phone.

  • I need to scan wirelessly from a MAC (OS 1.7 or higher) through Adobe Acrobat Pro X (or higher).  Have discovered that all in one printers say they are MAC compatible but will only scan when connected with a USB cable.  Would prefer a laser, color, all in

    I need to scan wirelessly from a MAC (OS 1.7 or higher) through Adobe Acrobat Pro X (or higher).  Have discovered that all in one printers say they are MAC compatible but will only scan when connected with a USB cable.  Would prefer a laser, color, all in one.  Does anyone have printer suggestions that you know will scan wirelessly?

    Great information.  
    -------------How do I give Kudos? | How do I mark a post as Solved? --------------------------------------------------------

  • If I change my number and forget to give to some people.  What message will they receive when they text my old number?

    If I change my number and forget to give to some people.  What message will they receive when they text my old number?   Thank you!

    more than likely they will never know the text did not go through. If the number was assigned to someone else they will get your text message. I did this last week and the person texted me back asking who I was. I responded and apologized and they said no problem.

  • Emails will not send when connected to wifi

    Emails on my iPad and iPhone will not send when connected to wifi, any help would be appreciated

    iOS: Unable to send or receive email
    http://support.apple.com/kb/TS3899
    Can’t Send Emails on iPad – Troubleshooting Steps
    http://ipadhelp.com/ipad-help/ipad-cant-send-emails-troubleshooting-steps/
    Setting up and troubleshooting Mail
    http://www.apple.com/support/ipad/assistant/mail/
    iPad Mail
    http://www.apple.com/support/ipad/mail/
    Try this first - Reset the iPad by holding down on the Sleep and Home buttons at the same time for about 10-15 seconds until the Apple Logo appears - ignore the red slider - let go of the buttons. (This is equivalent to rebooting your computer.)
    Or this - Delete the account in Mail and then set it up again. Settings->Mail, Contacts, Calendars -> Accounts   Tap on the Account, then on the red button that says Remove Account.
     Cheers, Tom

  • What firewire will connect 27 inch IMac with Cannon GL2 digital camcorder

    What firewire will connect 27 inch IMac with Cannon GL2 digital camcorder?

    According to the Canon spec's a > 4 to 9 pin firewire cables is what you will need, provided that you have a slightly older 27" iMac that still has a FireWire 800 port. 

  • Emails will not send when out of UK

    I have two 'normal' email accounts (BT and another provider) and a mobile me account, all set up on my iP3G, and my incoming and outgoing emails seem to work pretty well in the UK, either via WiFi connection or otherwise (3G, Edge etc).
    BUT when I travel to Europe (France, Belgium so far) my emails just will not send, whether connected by WiFi or via the local phone carrier. I can receive emails OK, but they won't go out. I have tried the trick of including the outgoing server of my UK carrier (O2) as an additional server for each of the accounts, and putting all the outgoing server details on all the accounts as fallbacks, but still no joy.
    I've tried referring to Apple website's UK email server details page, but this seems to have contradictions in it, with server details differing from those given by O2 and BT. Who is right?
    This is seriously limiting my 3G's usefulness as a business device, as I'm still effectively isolated when abroad. Is there something like port numbers that I need to change, or have I missed something simple (which I'm quite happy to accept!!)?
    Cheers
    CB

    One account is Yahoo! and you are not allowed to change the config - Apple has it all set up for you (host name not shown just text alias "Yahoo! SMTP Server" though it is something like smtp.yahoo.com or mail.smtp.yahoo.com - I could check this online through Yahoo! mail help but I wouldn't rule out Apple having a separate server with Yahoo!). For what it's worth SSL is OFF, Authentication; Password, and Server Port = 0.
    The other account is my personal business exchange account (Fasthost.com). Hostname is exchange.xxx.co.uk, and SSL is ON (Fasthost requires it). I do not see anywhere I could set Authentication password or Server Port. I also have Domain set as EXCHANGE. Presumably because it is EXCHANGE and not SMTP?
    It seems that I have a separate config because I am using Exchange. You may be on to something - could be in your mail setup.

  • What method will be called when an javabean terminates?

    Hi,
    I am using a java bean in my jsp application with scope "application". I know that this java bean will be terminated only when the server stops or shuts down.
    I need to cleanup something manually when the server shuts down. Can anyone tell me what method will be called, or that I can override, to clean up?
    Please advise.
    Damien

    Hi,
    I tried to implement the ServletContextListener, the ServletContextAttributeListener and the finalize methods, but I find that all of them are not called when I shut down the server manually.
    I am using an Apache Tomcat 4.0 server. I implement the methods as follows:
    public class RTPMainServer implements ServletContextListener, ServletContextAttributeListener
    public void contextDestroyed(ServletContextEvent scb)
    System.out.println("Server shutdown");
    System.out.println(scb.getServletContext());
    sourceSwitch.Cleanup();
    public void contextInitialized (ServletContextEvent scb)
    System.out.println("Server initialized");
    public void attributeAdded (ServletContextAttributeEvent scab)
    System.out.println("Mainserver added");
    public void attributeRemoved (ServletContextAttributeEvent scab)
    System.out.println("MainServer removed");
    public void attributeReplaced (ServletContextAttributeEvent scab)
    System.out.println("Attribute replaced");
    protected void finalize()
    System.out.println("Mainserver garbage collected");
    Can anyone help? Thanks
    Damien

  • What command will be executed when I schedule job via DB13

    Hi all,
    How do I get what command(full syntax) will be executed when I schedule jobs via DB13?
    For example:
    - Action: REORG of Tables in Tablespace(s)
    - Tablespaces: "WI6#BTABD" is selected
    - "Use Temporary Tablespaces" is selected
    I think this is a really basic question...
    Could you give me some advice?
    Thanks in advance,
    Ikue

    Hi Ikue,
    yes,  you won't see, what the 'REORG for all tablespaces is doing. But it's not really necessary. Its's simply always the same call
    REORG TABLE <tabname> INDEX <primary key> ALLOW NO ACCESS
    and optionally the addition  USE <tempspace>, if you have selected this option in DB13.  And it is called for each table that is located in the tablespace(s) which you have specified.
    The 'REORG for set of tables' is quite new. It is available with Basis Support Package 7.0 SP12. Before there was only a job to Reorg a single table.
    The REORG for flagged tables is a deprecated job.
    If you want to know more about the various REORG jobs and when and how to use them, then you should look at note 431430
    Best regards
    Ralf

  • What iPhone will be free when the iPhone 6 comes out?

    Right now, the iPhone 4s is "free" meaning the price of the phone it's self is $0, but you have to get a data plan along with that. I am interested in getting an iPhone so I was wondering if I should wait, because will the phone that is "free" change to the iPhone 5 or 5c when the iPhone 6 does out? Or will it still be the 4s? Thank you for reading my question and I would appreciate it if you would respond

    This is a user to user forum. no one here can possibly know what iPhone model will be free if any with a plan after the nest iPhone model is announced. That is something between Apple and the carriers.
    For iPhone specific questions please post in the iPhone forum. Using iPhone
    This question will likely be moved there shortly.

  • My iTunes 10.4 will not open when connected with my iPod Touch (v.4.3.5), however, it used to in the past- can anyone help me?  Thanks.

    I am curious as to why my iTunes 10.4 won't open when connected with my Touch (v.4.3.5).  iTunes used to open  when connected with my Touch.  Can anyone help me?  Thankyou.

    I have got a solution, it was shared on another 'apple support coummunity' board:
    https://discussions.apple.com/message/15830348#15830348
    It worked for me

  • What devices will Siri be included in with the IOS 6?

    Will the iPad have Siri with the IOS 6 update?

    Apple - iOS 6 Preview contains all that is publicly known about iOS 6.

  • Droid Charge hotspot will not send an email with an attachment.

    I have a Droid Charge phone.  When I use it as a hotspot and send an email from my computer with an attachment the connections times out.  It will send an email okay as long as there aren't any attachments associated with it.  Does anyone have any ideas as to how to fix this problem?  By the way, it downloads emails with attachments just fine!  Great phone otherwise.
    Thanks...

    Sammuel,
    I tried .pdf, jpeg, bmp, docx, doc, bmp.... nothing will send.
    I tried it with my laptop loaded with XP and I tried it with a laptop loaded with Windows 7. Same results - it timed out!
    I took my phone to the local Verizon store and they tried MY hotspot with THEIR computer - same problem, would not send!  I took it to a Verizon sales booth in Sam's club and they could not send an attachment using their computer and my hotspot either!
    I later went back to the Verizon store and the salesman there had an I-phone and she set up a hotspot on her phone. I then sent an attachment using my computer and HER hotspot - no problem, went thru just fine!  I sent about 10 more attachments that ranged from 500 KB to 2.6 MB and all went thru without a hitch!  I tried my hotspot again and it would not send!
    Verizon sent me a replacement phone - same problem.  They sent me ANOTHER replacement phone - same problem!
    A friend of mine has a HTC phone and an account with Sprint - I tried his hotspot.  At the exact same location I tried a pdf file of 2.6 MB with my computer using my Charge hotspot and it would NOT send it.  I then used his hotspot and sent the exact same file and it went thru without any problems.
    So now what?
    Oh, I had Verizon make me a new SIM card but that didn't help.  By the way, I think I've talked to about every Verizon tech at their 800 number and I don't think taking the battery out and resetting the phone is going to work - I've done it about 50 times now! (I'm not exaggerating!)
    This is a business phone so I'm going to turn the problem over to our person that handles our account with Verizon.  I had an AT&T phone before and it didn't have any problems.  I don't have the time for this type of headache so I think I'll go back to  AT&T since we have an account with them too!
    I'm not saying that Verizon is a bad company.... I just don't have time to deal with this!  This has been going on for over a month.

  • Will applications update when downloaded with a different iTunes account?

    Here is my scenario:
    My girlfriend bought an iPhone. To sync her contacts I used iTunes on my computer, unknowlingly setting up her iPhone to have my iTunes account set up on it. Since I didn't realize my iTunes account was saved to her iPhone, she proceeded to download several free apps to her phone, all under my account.
    After realizing what had happened when we tried to sync the iPhone to her computer, I did some research on the web and figured out how to get her iTunes account on the iPhone (I accesse the store on her computer and then synced her iPhone to it - problem solved). To allow her to continue using the applications on her phone, I authorized her computer to use my iTunes account.
    My question: If her phone now has her iTunes account, but still has some applications originally downloaded under my account will the app store still check for updates for these applications?
    Also, are there any other considerations I should be aware of with this situation?
    Thanks for your help,
    George

    Free applications are easy to "re-purchase"
    Lets say you bought Travel Planning software for $39 under an appleID with your work email address. Then you got a mobileMe account for personal use and that of course is an appleID too. Well, good luck getting updates for your $39 purchase. You "can" do it...but it means you have to logon to the iTunes store as the old account get the updates, log back into the first account to get updates for the apps purchased with that account...and then sync to the iPhone. Lots of fun.

  • What problems will I encounter when I upgrade to leopard?

    Hi,
    I'm going to purchase a Leopard upgrade for my MacBook Pro, but i've read alot of problems that users are encountering on this forum (Saying that, I've been on the MacBook Pro forum and there's alot of posts concerning issues/problems with this Laptop, but I have not ever had any).
    So is there any initial problems that I WILL encounter when upgrading my MacBook Pro 1GB 2.16GHz Intel Duo Core from 10.4.11 to 10.5.1?
    Regards,

    I'm still awaiting delivery of OSX Leopard, but I think what I might do once it arrives is to just upgrade with no backup of my current 10.4.11 on an external Hard Drive. What could possibly go wrong? nothing really has with any apple product i've bought so far.
    That's just plain foolish. Never ever upgrade without a backup. We get "this operating system ate my hard drive posts" here all the time. Why? Not because the operating system is flawed, but because people don't take proper precautions. No operating system can handle:
    1. Corrupt system data files.
    2. Third party drivers and firmware that aren't updated.
    3. Lack of disc space.
    4. Directory damage.
    5. RAM that hasn't been completely tested.
    With every update, a different angle on the problems above appears to happen, because each update accesses data files slightly differently, whether to match newer specs for information, or to better manage memory for other types of applications which need better memory management. Unfortunately unless you are using a vanilla system, which most people aren't, your chances of success diminish with each new addon you put in. See my upgrade FAQ*:
    http://www.macmaps.com/upgradefaq.html
    And NEVER EVER upgrade without at least two backups.
    - * Links to my pages may give me compensation.

Maybe you are looking for