Problem with traffic between devices in same network

Hey,
I’ve recently started working with a MikroTik device that was previously configured by someone else in the company. While internet access is functioning correctly for all connected devices, I’ve encountered an issue where devices on the local network are unable to communicate with each other—for example, a PC is unable to connect to a network printer.

I’ve attempted to troubleshoot this issue but haven’t been successful so far. I would appreciate any guidance or suggestions on how to resolve this.

I’ve used Quick Set to get into Router Mode and was able to set Address list + DHCP

A couple of things …

1- Quickset is ONLY to be used on a pristine new device (or after reset) and normally never again after that. It can cause troubles when used on an already configured device.
2- most likely some firewall rules are blocking you.

Export your config and then post here for review.
Also add a small diagram indicating how the device is connected in your network as well as requirements whoch should be able to do what (or what not).

Terminal
/export file=anynameyouwish
move file to PC
Edit file and remove serial, public IP, any sensitive info
Post contents back here between [__code] [/__code] quotes for easier readability.

Thank you for your assistance.

I have received a request regarding an issue where the internet connection was not functioning at the location where the MikroTik device is installed. As the ISP settings had not been configured upon connection, I utilized the Quick Set tool to input the necessary parameters. All other settings had already been configured prior to this intervention.

# model = RBD53iG-5HacD2HnD
# serial number = XXXXXXX
/interface bridge
add admin-mac=XXXXXXXXXX auto-mac=no comment=defconf name=bridge
/interface wireless
set [ find default-name=wlan1 ] band=2ghz-b/g/n channel-width=20/40mhz-XX \
    disabled=no distance=indoors frequency=auto installation=indoor mode=\
    ap-bridge ssid=MikroTik-68BD09 wireless-protocol=802.11
set [ find default-name=wlan2 ] band=5ghz-a/n/ac channel-width=\
    20/40/80mhz-XXXX country=poland disabled=no distance=indoors frequency=\
    auto installation=indoor mode=ap-bridge ssid="Regatta Designer" \
    wireless-protocol=802.11
/interface list
add comment=defconf name=WAN
add comment=defconf name=LAN
/interface wireless security-profiles
set [ find default=yes ] authentication-types=wpa2-psk mode=dynamic-keys \
    supplicant-identity=MikroTik
/ip pool
add name=default-dhcp ranges=192.168.88.10-192.168.88.254
/ip dhcp-server
add address-pool=default-dhcp interface=bridge lease-time=10m name=defconf
/interface bridge port
add bridge=bridge comment=defconf interface=ether2
add bridge=bridge comment=defconf interface=ether3
add bridge=bridge comment=defconf interface=ether4
add bridge=bridge comment=defconf interface=ether5
add bridge=bridge comment=defconf interface=wlan1
add bridge=bridge comment=defconf interface=wlan2
/ip firewall connection tracking
set udp-timeout=10s
/ip neighbor discovery-settings
set discover-interface-list=LAN
/interface list member
add comment=defconf interface=bridge list=LAN
add comment=defconf interface=ether1 list=WAN
/interface ovpn-server server
add mac-address=XXXXXXXXX name=ovpn-server1
/ip address
add address=192.168.88.1/24 comment=defconf interface=bridge network=\
    192.168.88.0
add address=XXXXXXXXX interface=ether1 network=XXXXXXXX
/ip arp
add address=192.168.88.250 interface=bridge mac-address=XXXXXXXXX
/ip cloud
set ddns-enabled=yes
/ip cloud advanced
set use-local-address=yes
/ip dhcp-client
add comment=defconf disabled=yes interface=ether1
/ip dhcp-server lease
add address=192.168.88.250 client-id=1:XXXXXXXXX mac-address=\
    XXXXXXXXXX server=defconf
/ip dhcp-server network
add address=192.168.88.0/24 comment=defconf dns-server=192.168.88.1 gateway=\
    192.168.88.1
/ip dns
set allow-remote-requests=yes servers=XXXXXXXXXXX
/ip dns static
add address=192.168.88.1 comment=defconf name=router.lan type=A
/ip firewall filter
add action=accept chain=forward comment="defconf: accept in ipsec policy" \
    ipsec-policy=in,ipsec
add action=accept chain=forward comment="defconf: accept out ipsec policy" \
    ipsec-policy=out,ipsec
add action=fasttrack-connection chain=forward comment="defconf: fasttrack" \
    connection-state=established,related hw-offload=yes
add action=accept chain=forward comment=\
    "defconf: accept established,related, untracked" connection-state=\
    established,related,untracked
add action=accept chain=forward comment="ruch w sieci LAN" dst-address=\
    192.168.88.0/24 src-address=192.168.88.0/24
add action=drop chain=forward comment="defconf: drop invalid" \
    connection-state=invalid
add action=drop chain=forward comment=\
    "defconf: drop all from WAN not DSTNATed" connection-nat-state=!dstnat \
    connection-state=new in-interface-list=WAN
add action=accept chain=input protocol=icmp
add action=accept chain=input connection-state=established
add action=accept chain=input connection-state=related
add action=drop chain=input disabled=yes in-interface-list=!LAN
add action=accept chain=input dst-port=8291 protocol=tcp
/ip firewall nat
add action=masquerade chain=srcnat comment="defconf: masquerade" \
    ipsec-policy=out,none out-interface-list=WAN
/ip ipsec profile
set [ find default=yes ] dpd-interval=2m dpd-maximum-failures=5
/ipv6 firewall address-list
add address=::/128 comment="defconf: unspecified address" list=bad_ipv6
add address=::1/128 comment="defconf: lo" list=bad_ipv6
add address=fec0::/10 comment="defconf: site-local" list=bad_ipv6
add address=::ffff:0.0.0.0/96 comment="defconf: ipv4-mapped" list=bad_ipv6
add address=::/96 comment="defconf: ipv4 compat" list=bad_ipv6
add address=100::/64 comment="defconf: discard only " list=bad_ipv6
add address=2001:db8::/32 comment="defconf: documentation" list=bad_ipv6
add address=2001:10::/28 comment="defconf: ORCHID" list=bad_ipv6
add address=3ffe::/16 comment="defconf: 6bone" list=bad_ipv6
/ipv6 firewall filter
add action=accept chain=input comment=\
    "defconf: accept established,related,untracked" connection-state=\
    established,related,untracked
add action=drop chain=input comment="defconf: drop invalid" connection-state=\
    invalid
add action=accept chain=input comment="defconf: accept ICMPv6" protocol=\
    icmpv6
add action=accept chain=input comment="defconf: accept UDP traceroute" \
    dst-port=33434-33534 protocol=udp
add action=accept chain=input comment=\
    "defconf: accept DHCPv6-Client prefix delegation." dst-port=546 protocol=\
    udp src-address=fe80::/10
add action=accept chain=input comment="defconf: accept IKE" dst-port=500,4500 \
    protocol=udp
add action=accept chain=input comment="defconf: accept ipsec AH" protocol=\
    ipsec-ah
add action=accept chain=input comment="defconf: accept ipsec ESP" protocol=\
    ipsec-esp
add action=accept chain=input comment=\
    "defconf: accept all that matches ipsec policy" ipsec-policy=in,ipsec
add action=drop chain=input comment=\
    "defconf: drop everything else not coming from LAN" in-interface-list=\
    !LAN
add action=accept chain=forward comment=\
    "defconf: accept established,related,untracked" connection-state=\
    established,related,untracked
add action=drop chain=forward comment="defconf: drop invalid" \
    connection-state=invalid
add action=drop chain=forward comment=\
    "defconf: drop packets with bad src ipv6" src-address-list=bad_ipv6
add action=drop chain=forward comment=\
    "defconf: drop packets with bad dst ipv6" dst-address-list=bad_ipv6
add action=drop chain=forward comment="defconf: rfc4890 drop hop-limit=1" \
    hop-limit=equal:1 protocol=icmpv6
add action=accept chain=forward comment="defconf: accept ICMPv6" protocol=\
    icmpv6
add action=accept chain=forward comment="defconf: accept HIP" protocol=139
add action=accept chain=forward comment="defconf: accept IKE" dst-port=\
    500,4500 protocol=udp
add action=accept chain=forward comment="defconf: accept ipsec AH" protocol=\
    ipsec-ah
add action=accept chain=forward comment="defconf: accept ipsec ESP" protocol=\
    ipsec-esp
add action=accept chain=forward comment=\
    "defconf: accept all that matches ipsec policy" ipsec-policy=in,ipsec
add action=drop chain=forward comment=\
    "defconf: drop everything else not coming from LAN" in-interface-list=\
    !LAN
/system clock
set time-zone-name=Europe/Warsaw
/system identity
set name="XXXXXXXXXX"
/system note
set show-at-login=no
/tool mac-server
set allowed-interface-list=LAN
/tool mac-server mac-winbox
set allowed-interface-list=LAN

Conection is simple

ISP → Microtick → TP LINK SWITCH → PC1, PC2, Printer.

Remove connection from internet immediately router is setup UNSAFE.
add action=drop chain=input disabled=yes in-interface-list=!LAN
add action=accept chain=input dst-port=8291 protocol=tcp

Then netinstall router to ensure a clean restart.

There was nothing inherently wrong with the forward rules as they followed the default rules quite closely.
The only problem was you added an unnecesssary rule allow Subnet users access to each other.
They already do at layer2 being in the same subnet. Attempting to put a layer3 firewall rule on them was incorrect.
Just move invalid rule up to where i have put it here:

/ip firewall filter
add action=accept chain=forward comment=“defconf: accept in ipsec policy”
ipsec-policy=in,ipsec
add action=accept chain=forward comment=“defconf: accept out ipsec policy”
ipsec-policy=out,ipsec
add action=fasttrack-connection chain=forward comment=“defconf: fasttrack”
connection-state=established,related hw-offload=yes
add action=accept chain=forward comment=
“defconf: accept established,related, untracked” connection-state=
established,related,untracked
add action=drop chain=forward comment=“defconf: drop invalid”
connection-state=invalid
add action=accept chain=forward comment=“ruch w sieci LAN” dst-address=
192.168.88.0/24 src-address=192.168.88.0/24
add action=drop chain=forward comment=
“defconf: drop all from WAN not DSTNATed” connection-nat-state=!dstnat
connection-state=new in-interface-list=WAN
[/size]

The real problem is the input chain or lack thereof fixed HERE:
/ip firewall
add action=accept chain=input connection-state=established,related,untracked
add action=drop chain=input connection-state=invalid
add action=accept chain=input protocol=icmp
add action=accept chain=input in-interface-list=LAN
add action=drop chain=input comment=“Drop all else”
{ ensure you put this rule in this location, but implemented last of all rules }