[Dnsmasq-discuss] Behavior on DHCP denied

[0zl]

Hello,

This is an issue I've experienced with ESP8266 and proxy ARP on my WiFi 
network. I was able to work around it by assigning the devices an 
infinite lease, however I think dnsmasq's behavior is undesirable.

In short, ESP8266 is on a network with proxy ARP setup; getting the 
initial lease works fine, however once proxy ARP kicks in it fails to 
renew. This is the chain of events leading up to the issue:

  * MCU tries to renew the address
  * dnsmasq properly renews its address
  * MCU sends an ARP request to check if the address is in use and
    receives an ARP reply from the router because of proxy ARP
  * MCU mistakenly believes that the address was assigned already even
    though it was not, sends a DENIED message back to dnsmasq and tries
    again
  * dnsmasq then allocates the exact same address that the MCU just rejected

I think in this scenario, dnsmasq should try to allocate a different 
address because MCU has rejected it already.

Not sure what people in this mailing list think, but it feels like 
dnsmasq shouldn't be doing this.

All the best,
0zl.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/attachments/20230418/9f4c28df/attachment.htm>