RFC 5227, "IPv4 Address Conflict Detection", July 2008

Errata ID: 8077
Status: Reported
Type: Technical
Publication Format(s) : TEXT
Reported By: Gopinatha Rao P
Date Reported: 2024-08-14

Throughout the document, when it says:

2.1.2

It should say:

Handling ARP Probe on a Router with Local Proxy ARP configured:

Host A with IP X is learnt on Router R on which Local Proxy ARP 
is configured. When another Host B is configured with same IP X 
connected to same Router R, there would be a ARP Probe sent from 
Host B received on Router R.

Router R with Local Proxy ARP configuration would respond to the 
ARP Probe indicating the IP X is already in use. In this case 
Router R wouldn't perform validity of IP X based on the ARP Probe. 
If the validity of the IP address is performed for every ARP Probe 
then there would be large amount of ARP request packets in the 
network.

As Local Proxy ARP functionality is to perform a "proxy" on behalf 
of the intended host, it would take preference over flooding of 
ARP Probes.

Notes:

There is this above explained issue on how DAD ARP works with Local Proxy ARP enabled. There has to be a clarification from the RFC on what is the mandated behavior when Local Proxy ARP is configured and there is a DAD ARP packet received on it.

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