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CISCO threshold Problem

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    Bit Poster mrbari's Avatar
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    CISCO threshold Problem

    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.

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    A quick google search turned up the following:
    %IP_VFR-4-FRAG_TABLE_OVERFLOW : [chars]: the fragment table has reached its maximum threshold [dec]

    Explanation The number of datagrams being reassembled at any one time has reached it maximum limit.

    Recommended Action Increase the maximum number of datagrams that can be reassembled by entering the ip virtual-reassembly max-reassemblies number command, with number being the maximum number of datagrams that can be reassembled at any one time.
    I'll leave it to CISCO experts as to whether this sort of error is to be expected on a home router.

    Harry.

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    Quote Originally Posted by hbroomhall View Post
    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.
    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

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    Megabyte Poster Spice_Weasel's Avatar
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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

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    Quote Originally Posted by Spice_Weasel View Post
    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
    And this is why your aiming to be a CCIE (although i read about this an hour ago lol)

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