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Broadcast storm


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#1 krnl

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Posted 26 November 2011 - 10:10 PM

hi everyone

Sometimes i face broadcast storm in LAN which has 1000+ users. so i want 2 about how can i stop broadcast storm in LAN
nd is there ny s/w to find out broadcasting device in the n/w?????
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#2 MarkinManchester

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Posted 28 November 2011 - 05:45 AM

split it into two vlans, use wireshark to find the source of all the b-cast traffic
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#3 ZigAA

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Posted 28 November 2011 - 06:24 AM

spanning-tree should block broadcast storms. but all switches should support it. it's hard to locate the source. most likely is some loopback. check fiber interfaces or some users that are connecing some cables to switches
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#4 chrcel

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Posted 28 November 2011 - 07:28 PM

spanning-tree should block broadcast storms.

oh really? spanning tree only cares about loop free topology. it does not give a s..t about IP.
@krnl depending on what are your switches you can configure storm-control and let it send you traps or even disable violating ports.
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#5 krnl

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Posted 28 November 2011 - 11:45 PM

thnks a lot 4 your suggestions.

@MarkinManchester: split n/w into 2 vlan is not possible at this moment .

@ZigAA: STP is a good way to reduce b/c storm but i when b/c storm occurs at that time how can i find that?
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#6 MarkinManchester

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Posted 29 November 2011 - 12:05 AM

STP stops loops in a L2 topology, broadcast. you have an issue at L3. If you have a well configured network e.g. access, distribution, core all you need to do is setup monitor ports and put an old PC with wireshark on this monitor ports and wait for the next incidence of this problem.

Examine the logs and find the culprit, if you have a flat L2 network with that many hosts you need to do something with it quickly as the problem will only get bigger.

Mark
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#7 Ash90

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Posted 03 December 2011 - 05:30 PM

Mark's first advice is the only best solution to start with. Think seriously otherwise, as Mark suggested the problem become an avalanche. Better hurry and avoid it.
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#8 krnl

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Posted 08 December 2011 - 01:40 AM

@everyone:--->Thank a lot
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