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Invalid ARP request flooding at 3750 switch

Say i have this 3750 switch inside my company. Somehow, the connection to the switch is slow. The only way to access to the switch is using console.

Inside the console mode, I could not type in any words because the log messages appear faster than my typing.

The only way to stop the log messages is to type in "no logging console" during the period when the switches is re-boot and before the log message actually come back.

However, this is only temporary. When i re-able the logging console back, the flood ARP messages actually come back.

The configuration of the switch in global mode:

ip dhcp snooping vlan xxx- yyy

no ip dhcp snooping information option

ip dhcp snooping

ip arp inspection vlan xxx-yyy

ip arp inspection validate src-mac dst-mac

The configuration of the switch in interface mode:

ip verify source

ip dhcp snooping limit rate 15

Does anyone have any ways to find and solve the root cause of it? Could the root cause be DHCP? Could it be one of the bugs in 3750 switches?

However, i don't think the root cause is DHCP flooding as the error messages only show Invalid ARP request for all the interfaces.

1 REPLY
Bronze

Re: Invalid ARP request flooding at 3750 switch

Approximately 30% of CPU utilization (when flooding 200byte packets) is caused by ICMP processing on the CPU. The cpu goes high if you do a clear arp after configuring the output. Here is the URL it will be helpful for the configuring the dhcp snooping

http://www.cisco.com/en/US/docs/switches/lan/catalyst3750/software/release/12.2_25_see/configuration/guide/swdhcp82.html

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