DHCP Discover broadcast on phones configured for Static IP.

[kriner]

I have a very large enterprise network with yealink phones. These phones T23G and T38, are configured with a static class A IP address. The phones which are configured for static services have been flooding the network with DHCP server requests. The IP address of the server it is looking for does not exists.

I have attached a screenshot showing the requests. Each mac address is different so all of my phones are looking for a DHCP server. Is there some sort of setting on the phone that can be changed to stop this ARP flood.

[Karl_Yealink]

Hi,

How many phones do you have?
Do you disable the DHCP function?
Can you send the configuration file to us, so we can check.
If possible, please help us to get the pcap and syslogs files, we can check something from them.
You can know more from the FAQ: http://support.yealink.com/faq/faqInfo?id=311

[kriner]

(03-09-2016 04:36 AM)Yealink_Karl Wrote:  Hi,

How many phones do you have?
Do you disable the DHCP function?
Can you send the configuration file to us, so we can check.
If possible, please help us to get the pcap and syslogs files, we can check something from them.
You can know more from the FAQ: http://support.yealink.com/faq/faqInfo?id=311

We have over 2,000 phones throughout the district.

Thanks for any help you can provide. I have disabled DHCP VLAN and DHCP for auto-provision but the DHCP broadcasts continue here are the files you requested.

[Karl_Yealink]

I will contact with our R&D about this problem then give you respond.

[Karl_Yealink]

We check the files, but we find the PCAP file and syslog don't get from the same phone.
From the PCAP file, we find the phone send the discover packet, but from the syslog, the phone don't send.
The two files don't get from the same phone, so we can do an correct analyze.
Please help us to get the files from the same phone again, so we can check the problem.

[kriner]

(04-13-2016 05:29 AM)Yealink_Karl Wrote:  We check the files, but we find the PCAP file and syslog don't get from the same phone.
From the PCAP file, we find the phone send the discover packet, but from the syslog, the phone don't send.
The two files don't get from the same phone, so we can do an correct analyze.
Please help us to get the files from the same phone again, so we can check the problem.

I have attached the files TY for your time.

[Karl_Yealink]

Hi,

Please check whether there are some other phones enable the DHCP function in the same network environment.
If there are some phone enable the DHCP function, the pcap will capture all DHCP discover packet.
You can check the PCAP file by yourself, the pcap capture most discover packet, but there is no discover packet from the captured phone.
You can check the transaction ID, this is the mac of the phones.