05-25-2022 08:14 AM
Hello,
Can anyone help about this persistent log issue that is being broadcast on my switch vlan. I don't know the cause of the consistent broadcast arp and would like to know the solution to it.
Switch model: C3850-48u
Switch version: 03.07.02E
Sw image: cat3k_caa-universalk9
Switch uptime: 3 years, 20 weeks, 2 days, 13 hours, 7 minutes
Attached is a screenshot from from my switch log
Solved! Go to Solution.
05-25-2022 03:04 PM
In my experience these are not normal log messages. It looks perhaps like debugging messages. Can you post the output of show debug?
05-25-2022 05:34 PM
@Richard Burts you are 100% correct.
someone left debugging on for ARP.
I undebugged all and no more arp output again. please find attached.
Thanks everyone for this wonderful support.
05-25-2022 08:47 AM
Hi,
What is vlan 2 used for? Is this a management vlan or a user vlan?
HTH
05-25-2022 08:50 AM
Hello Reza,
Thanks for looking at this for me.
Vlan 2 is for user vlan and all access ports are connected to it.
05-25-2022 09:34 AM
Hi,
Can you describe the problem you are encountering?
HTH
05-25-2022 09:54 AM
All network activities are up and running but my log keep getting flooded with ARP req is dequeued & IP ARP: ignored gratuitous arp. I dont know the cause and am looking for solution. I attached part of screenshot of my log to understand the cause and solution. I have no protection configured on any of the access port.
The excessive log is slowing down any cli command I tried running on the switchport.
05-25-2022 12:39 PM
I think it normal IP tracking traffic if you config it in SW,
SW send ARP to host connect to port.
05-25-2022 01:04 PM
@MHM Cisco World Thank you for your response. IP device tracking wasn't configure on any of the port on this switch. Please find attached and advice why I am getting tons of broadcast gratitious arp, dequeued in my log. Thank you.
05-25-2022 01:15 PM - edited 05-25-2022 04:40 PM
see above comment
05-25-2022 01:32 PM
I didn't see it in the uplink switch (Trunk). How can I stop it from filling up the log? Thank you.
05-25-2022 03:04 PM
In my experience these are not normal log messages. It looks perhaps like debugging messages. Can you post the output of show debug?
05-25-2022 04:40 PM
OK,
the Client is get IP form DHCP ?
are you config the default GW point to VLAN 2 SVI ?? if not then any client will send ARP ask MAC address for GW.
check this point.
05-25-2022 05:34 PM
@Richard Burts you are 100% correct.
someone left debugging on for ARP.
I undebugged all and no more arp output again. please find attached.
Thanks everyone for this wonderful support.
05-25-2022 11:43 PM
You are welcome. I am glad that my suggestion pointed you in the right direction. Thank you for marking this question as solved. This will help other participants in the community to identify discussions which have helpful information. This community is an excellent place to ask questions and to learn about networking. I hope to see you continue to be active in the community.
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