CISCO threshold Problem

Discussion in 'General Cisco Certifications' started by mrbari, Aug 4, 2008.

  1. mrbari

    mrbari Bit Poster

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    Hi everybody,

    On my cisco 1812 router, I am repeatedly getting this following message....

    14w2d: %IP_VFR-4-FRAG_TABLE_OVERFLOW: FastEthernet0: the fragment table has reached its maximum threshold 16

    I dont actually understand what is the meaning of that.

    Any clue, how to resolve it.

    Thanks.
     
  2. hbroomhall

    hbroomhall Petabyte Poster Gold Member

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    A quick google search turned up the following:
    I'll leave it to CISCO experts as to whether this sort of error is to be expected on a home router.

    Harry.
     
    Certifications: ECDL A+ Network+ i-Net+
    WIP: Server+
  3. kevicho

    kevicho Gigabyte Poster

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    At a guess id say you have lots of traffic coming in, and the current config is unable to process that many connections.

    ip virtual-reassembly max-reassemblies "number"

    Looks like what needs to be increased, had a quick google and nothing else seemed to spring up
     
    Certifications: A+, Net+, MCSA Server 2003, 2008, Windows XP & 7 , ITIL V3 Foundation
    WIP: CCNA Renewal
  4. Spice_Weasel

    Spice_Weasel Kilobyte Poster

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    IP packets that are fragmented are buffered by the router until reassembled and transmitted. The router will allocate space for a number of datagrams (and fragments per datagram) to be held waiting for reassembly. If too many fragmented datagrams are received you'll get the frag_table_overflow syslog message. You can increase the size of the fragment table, but it is also worth trying to find out what is causing the fragmentation - mtu issue? malicious activity? incorrect configuration somewhere?

    sh ip traffic will give you some information about fragments.

    Spice_Weasel
     
    Certifications: CCNA, CCNP, CCIP, JNCIA-ER, JNCIS-ER,MCP
    WIP: CCIE
  5. kevicho

    kevicho Gigabyte Poster

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    And this is why your aiming to be a CCIE (although i read about this an hour ago lol)
     
    Certifications: A+, Net+, MCSA Server 2003, 2008, Windows XP & 7 , ITIL V3 Foundation
    WIP: CCNA Renewal

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