02-19-2014 03:54 AM - edited 03-07-2019 06:17 PM
Hi all,
my customer has added IPv6 to their BYOD WLAN subnet and are seeing the following log messages on their Cat6k syslog
%IPV6_ND-6-DUPLICATE_INFO: DAD attempt detected for FE80:: on VlanABC
%IPV6_ND-6-DUPLICATE_INFO: DAD attempt detected for FE80:: on VlanXYZ
%IPV6_ND-4-DUPLICATE_OPTIMISTIC: Duplicate address FE80:: on VlanYYY
%VRRS-6-INFO: Internal info, VlanABC: Duplicate address detected on the network FE80:: -Process= "IPv6 Input", ipl= 0, pid= 577
The FE80:: is their LL-HSRP IPv6 address for these vlans . It seems that quite a number of clients is probing the RA address.
my customer is querying if there is a way to disable this?
any advice please?
thanks in advance
Lance
02-19-2014 05:35 AM
Hi,
the clients that are probing this address is normal if they have it configured as they ipv6 default gateway.
DAD attempts is normal way for IPv6 to test if it can use an IP.
The only problem I see here is that for VlanABC there was a duplicate address detected by the catalyst but I'm not an expert with this platform so I can't tell if this is problematic here.
Regards
Alain
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04-01-2024 06:44 AM
Hello,
I am facing the same issue, have you found a fix?
Many thanks,
Hamid
04-01-2024 07:17 AM
Hi @hara12386 ,
This post is 10 years old. Could you please open a new request and provide the relevant information.
Regards,
04-01-2024 07:27 AM
Hello @Harold Ritter
Thank you for your feedback, I found the following bug CSCvd81898 that fits, so I applied the workaround and I am monitoring the situation.
In case it won't fix the issue, I will open a new request.
Thank you,
Hamid
04-01-2024 08:15 AM
Thanks @hara12386 . Let us know if the workaround for CSCvd81898 does not solve the issue.
Regards,
05-09-2024 01:13 AM
Hello,
Just to let you know that this didn't fix the issue, I had to open a case with cisco TAC that is still in progress..
Many thanks,
Hamid
05-09-2024 06:47 AM
Hi @hara12386 ,
Thanks for the feedback. Another work around would be to disable DAD with the following command under the interface:
ipv6 nd dad attempts 0
Regards,
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