B

Visitor

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3 Messages

Fri, Jul 29, 2022 7:27 PM

Please Fix Broken dhcp-server-identifier Advertisement (or allow the current one to accept unicast DHCP Requests)

My router is currentlyserved an IPv4 address from Xfinity via DHCP with 96.113.84.144 designated as the dhcp-server-identifier in the lease.  However, this server is not responding to DHCP unicast requests.  As a result, my router has to fallback to using the 255.255.255.255 broadcast to renew its lease before it expires and an entirely (?) different server responds.  Here's a copy-paste from wireshark illustrating the issue.

No. Time Source Destination Protocol Length Info
26 344.424617 <my-public-ip> 96.113.84.144 DHCP 342 DHCP Request  - Transaction ID 0x70181f64
27 362.161344 <my-public-ip> 96.113.84.144 DHCP 342 DHCP Request  - Transaction ID 0x70181f64
28 382.648518 <my-public-ip> 255.255.255.255 DHCP 342 DHCP Request  - Transaction ID 0x70181f64
29 382.672195 96.120.101.17 <my-public-ip> DHCP 372 DHCP ACK      - Transaction ID 0x70181f64

This is pretty lazy network design and is starting to lead to issues where 96.120.101.17 isn't responding in a timely fashion and my lease drops (likewise breaking my connection temporarily), especially because the lease times lately have been smaller for "reasons".  Can a network engineer at Xfinity please update the server at 96.113.84.144 to respond to unicast DHCP requests or else update the dhcp-server-identifier to the correct IP?

Thank you.

Official Employee

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641 Messages

2 m ago

Hello there @bnerickson!  Thank you so much for taking the time to reach out to Xfinity Support with Digital Care here on our Community Forum.  We are so glad to hear from you and happy to assist in any way that we can.  No worries!  You have reached out to a team of experts, and we are going to get things squared away for you.  Please feel free to shoot us a private message with your full name and address so that we can get started on this for you. 

 

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Visitor

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3 Messages

2 m ago

It looks like the network engineers at Xfinity fixed this issue last night between 1:30am-3:00am PDT.  Log entries:

Aug  3 03:00:15 xyz dhclient[18448]: DHCPREQUEST on ens9 to 96.113.84.144 port 67 (xid=0x7757e06d)
Aug  3 03:00:15 xyz dhclient[18448]: DHCPACK from 96.113.84.144 (xid=0x7757e06d)
Aug  3 04:00:42 xyz dhclient[18448]: DHCPREQUEST on ens9 to 96.113.84.144 port 67 (xid=0x7757e06d)
Aug  3 04:00:42 xyz dhclient[18448]: DHCPACK from 96.113.84.144 (xid=0x7757e06d)

A later Wireshark capture:

No. Time Source Destination Protocol Length Info
2 1569.483631 <my-public-ip> 96.113.84.144 DHCP 342 DHCP Request  - Transaction ID 0x7757e06d
3 1569.504226 96.113.84.144 <my-public-ip> DHCP 372 DHCP ACK      - Transaction ID 0x7757e06d

Thanks unknown network engineer!  Much appreciated.  Hope there's monitoring to verify the DHCP server at 96.113.84.144 is working properly (assuming it was a service failure and not a configuration issue) 

XfinityAaron

Official Employee

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741 Messages

That is great to hear. Why I have you here, was there anything else we may assist you with today? -Aaron 

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Please, mark a reply as the Accepted Answer.tick

Visitor

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3 Messages

Nope, that's it.  Thank you.

XfinityAaron

Official Employee

 • 

741 Messages

You're welcome! 

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Please, mark a reply as the Accepted Answer.tick
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