pfSense » pfSense Plus

Problem description: Connections going to host 192.168.255.253 are being sent to 192.168.255.251

VLAN100 LAN: 192.168.255.248/29

pfsense: 192.168.255.249 MAC: 00:08:a2:0c:c4:1c ( SG-3100 22.05 )
Host: 192.168.255.251 MAC: f0:2f:74:d0:24:94 ( desktop computer ) connected to LAN1 of sg-3100
Host: 192.168.255.253 MAC: dc:a6:32:a5:47:19 ( raspberry pi 4b ) connected to LAN2 of switch unifi mini

topology:
desktop connected to (LAN1) pfsense
sg-3100 (LAN4) connected to switch unifi mini (LAN5)
raspberry pi 4b connected to (LAN2) switch mini

sg-3100 config:
0 1 3,4,5 Default System VLAN
1 100 1,2,4t,5t LAN (192.168.255.248/29)
2 10 3t,4t,5t WIFI
3 20 3t,5t GUEST
+++++++++++++++++++++++++++++++++++
1 LAN 1 100 (access port connected to 192.168.255.251)
2 LAN 2 100
3 LAN 3 1 (trunk) (port connected to an access point)
4 LAN 4 1 (trunk) (port connected to the switch unifi mini which has a VLAN100 access port (LAN2) connected to host 192.168.255.253)
5 LAN Uplink

Captures in pfsense and also on host 192.168.255.251 shows that the MAC addresses of the packets are correct but still they are be arriving to 192.168.255.251.

If I ssh to pfsense then ping 192.168.255.253, I can see that ping arriving in 192.168.255.251 with the following message:

Capture in host 192.168.255.251: As we can see below, the header is fine.

6645 117.957087565 192.168.255.249 192.168.255.253 ICMP 98 Echo (ping) request id=0x7640, seq=0/0, ttl=64 ( no response found !)

First ping I get the no response found as shown in packet 6645, then the following ICMP requests goes to the correct host (192.168.255.253).

Frame 510: 98 bytes on wire (784 bits), 98 bytes captured (784 bits) on interface enp7s0, id 0
Ethernet II, Src: ADIEngin_0c:c4:1c (00:08:a2:0c:c4:1c), Dst: Raspberr_a5:47:19 (dc:a6:32:a5:47:19)
Destination: Raspberr_a5:47:19 (dc:a6:32:a5:47:19)
Source: ADIEngin_0c:c4:1c (00:08:a2:0c:c4:1c)
Type: IPv4 (0x0800)
Internet Protocol Version 4, Src: 192.168.255.249, Dst: 192.168.255.253
Internet Control Message Protocol

Checking the ARP table in pfsense is fine, no problems there.

Please, let me know in case I can provide more information to help diagnose this problem.