Hello everyone,
i got an issue on my Mikrotik Router version 6.44.1. I set on the interfaces list the 'reply only' rule, in this way the only IP addresses written in the ARP are those issued from DHCP server.
When is rightly set on the ARP table the set flags are the following: dynamic, enabled, complete, DHCP.
When is wrongly set on the ARP table the set flags are : dynamic, enabled, in this way the user pc is not able to surfing on LAN/Internet despite the client has aquired the IP address.
This problem is random, it happended on various laptop.
Can you help us understand the problem?
Have you a solution to propose to us?

Waiting for your feedback.
Thanks.

Up
Does someone has informations about it?

No, but I have the same problem..... (With 6.45 beta 27)

I will set up a lab and test tonight on 6.44.1 and see if I can replicate the issue. I believe the arp is timing out and is only refreshed during the lease renewal. Typically, the DHCP lease is valid for 24 hours (default) and the arp timeout is 4 hours (default). I wonder if you reduce the dhcp lease to 4 hours, or increase the arp timeout to 24 hours and see if your issue resolves.

If it does, then that means the timer for arp is agnostic of the dhcp lease state. I will follow up in the thread if I see a different behavior in my test

Thanks for your feedback.
We will change the timeout of the ARP o DHCP, and we will see if the problem is solved.
Waiting your feedback after your test.

Hi,
to give more clarity to the problem I send you a screenshot of the recorded logs, it refers to the user on which we had the problems.
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10.10.10.1 Apr 05 14:25:21 dhcp,debug,packet dhcp3-aut received request with id 1839972259 from 0.0.0.0
10.10.10.1 Apr 05 14:25:21 dhcp,debug,packet ciaddr = 0.0.0.0
10.10.10.1 Apr 05 14:25:21 dhcp,debug,packet chaddr = 7C:67:A2:XX:XX:XX
10.10.10.1 Apr 05 14:25:21 dhcp,debug,packet Msg-Type = request
10.10.10.1 Apr 05 14:25:21 dhcp,debug,packet Client-Id = 01-7C-67-A2-XX-XX-XX
10.10.10.1 Apr 05 14:25:21 dhcp,debug,packet Address-Request = 10.10.30.32
10.10.10.1 Apr 05 14:25:21 dhcp,debug,packet Host-Name = "-host"
10.10.10.1 Apr 05 14:25:21 dhcp,debug,packet Client-FQDN = 00-00-00-4B-69-6E-65-74-6F-6E-2D-53-61-72-64-6F
10.10.10.1 Apr 05 14:25:21 dhcp,debug,packet Class-Id = "MSFT 5.0"
10.10.10.1 Apr 05 14:25:21 dhcp,debug,packet Parameter-List = Subnet-Mask,Router,Domain-Server,Domain-Name,Router-Discovery,Static-Route,Vendor-Specific,NETBIOS-Name-Server,NETBIOS-Node-Type,NETBIOS-Scope,Domain-Search,Classless-Route,MS-Classless-Route,Auto-Proxy-Config
10.10.10.1 Apr 05 14:25:25 dhcp,debug,packet dhcp3-aut received request with id 1839972259 from 0.0.0.0
10.10.10.1 Apr 05 14:25:25 dhcp,debug,packet ciaddr = 0.0.0.0
10.10.10.1 Apr 05 14:25:25 dhcp,debug,packet chaddr = 7C:67:A2:XX:XX:XX
10.10.10.1 Apr 05 14:25:25 dhcp,debug,packet Msg-Type = request
10.10.10.1 Apr 05 14:25:25 dhcp,debug,packet Client-Id = 01-7C-67-A2-XX-XX-XX
10.10.10.1 Apr 05 14:25:25 dhcp,debug,packet Address-Request = 10.10.30.32
10.10.10.1 Apr 05 14:25:25 dhcp,debug,packet Host-Name = "-host"
10.10.10.1 Apr 05 14:25:25 dhcp,debug,packet Client-FQDN = 00-00-00-4B-69-6E-65-74-6F-6E-2D-53-61-72-64-6F
10.10.10.1 Apr 05 14:25:25 dhcp,debug,packet Class-Id = "MSFT 5.0"
10.10.10.1 Apr 05 14:25:25 dhcp,debug,packet Parameter-List = Subnet-Mask,Router,Domain-Server,Domain-Name,Router-Discovery,Static-Route,Vendor-Specific,NETBIOS-Name-Server,NETBIOS-Node-Type,NETBIOS-Scope,Domain-Search,Classless-Route,MS-Classless-Route,Auto-Proxy-Config
10.10.10.1 Apr 05 14:25:29 dhcp,debug,packet dhcp3-aut received request with id 1839972259 from 0.0.0.0
10.10.10.1 Apr 05 14:25:29 dhcp,debug,packet secs = 1024
10.10.10.1 Apr 05 14:25:29 dhcp,debug,packet ciaddr = 0.0.0.0
10.10.10.1 Apr 05 14:25:29 dhcp,debug,packet chaddr = 7C:67:A2:XX:XX:XX
10.10.10.1 Apr 05 14:25:29 dhcp,debug,packet Msg-Type = request
10.10.10.1 Apr 05 14:25:29 dhcp,debug,packet Client-Id = 01-7C-67-A2-XX-XX-XX
10.10.10.1 Apr 05 14:25:29 dhcp,debug,packet Address-Request = 10.10.30.32
10.10.10.1 Apr 05 14:25:29 dhcp,debug,packet Host-Name = "-host"
10.10.10.1 Apr 05 14:25:29 dhcp,debug,packet Client-FQDN = 00-00-00-4B-69-6E-65-74-6F-6E-2D-53-61-72-64-6F
10.10.10.1 Apr 05 14:25:29 dhcp,debug,packet Class-Id = "MSFT 5.0"
10.10.10.1 Apr 05 14:25:29 dhcp,debug,packet Parameter-List = Subnet-Mask,Router,Domain-Server,Domain-Name,Router-Discovery,Static-Route,Vendor-Specific,NETBIOS-Name-Server,NETBIOS-Node-Type,NETBIOS-Scope,Domain-Search,Classless-Route,MS-Classless-Route,Auto-Proxy-Config
10.10.10.1 Apr 05 14:25:29 dhcp,info syslog-info dhcp3-aut assigned 10.10.30.32 to 7C:67:A2:XX:XX:XX
10.10.10.1 Apr 05 14:25:29 dhcp,info dhcp3-aut assigned 10.10.30.32 to 7C:67:A2:XX:XX:XX
10.10.10.1 Apr 05 14:25:29 dhcp,debug,packet dhcp3-aut sending ack with id 1839972259 to 10.10.30.32
10.10.10.1 Apr 05 14:25:29 dhcp,debug,packet ciaddr = 0.0.0.0
10.10.10.1 Apr 05 14:25:29 dhcp,debug,packet yiaddr = 10.10.30.32
10.10.10.1 Apr 05 14:25:29 dhcp,debug,packet siaddr = 10.10.30.1
10.10.10.1 Apr 05 14:25:29 dhcp,debug,packet chaddr = 7C:67:A2:XX:XX:XX
10.10.10.1 Apr 05 14:25:29 dhcp,debug,packet Msg-Type = ack
10.10.10.1 Apr 05 14:25:29 dhcp,debug,packet Server-Id = 10.10.30.1
10.10.10.1 Apr 05 14:25:29 dhcp,debug,packet Address-Time = 86400
10.10.10.1 Apr 05 14:25:29 dhcp,debug,packet Subnet-Mask = 255.255.255.0
10.10.10.1 Apr 05 14:25:29 dhcp,debug,packet Router = 10.10.30.1
10.10.10.1 Apr 05 14:25:29 dhcp,debug,packet Domain-Server = 8.8.8.8,8.8.4.4
10.10.10.1 Apr 05 14:25:29 dhcp,error dhcp3-aut failed to add arp entry for IP 10.10.30.32: already have such arp (6)
[*]

We update soon.

I'm having the same problem ... anyone with a solution to fix it. Thanks