I assume you have addressed the untagged interface of the RB951 and the tagged sub-interface in different subnets.
These 2 subnets should be visible in the routing table of the RB. If they are, nothing more should be done.
Yes, you are right, it is so. Funny thing the day everything was set up there was a connection between these subnets. I even had to make 2 rules to drop packets forward from one subnet to another. Now I deleted these 2 rules and nothing happens.
Are the hosts from vlan2 visible in the ARP table of the RB? Can they ping their default gateway? Can they ping the default gateway of the untagged interface?
Yes, hosts can ping their gateway. And I can ping hosts from RB terminal. But I can't ping from host PC-0 to host PC-1 (2, 3).
There's not really much to be done on the RB...
Post the output of /ip address print, /interface print detail, /ip route print
[admin@MikroTik] > /ip address print
Flags: X - disabled, I - invalid, D - dynamic
# ADDRESS NETWORK INTERFACE
0 192.168.0.1/24 192.168.0.0 ether2-master-local
1 192.168.2.1/24 192.168.2.0 vlan2_1C
2 D 10.0.211.153/24 10.0.211.0 ether1-gateway
3 D 194.44.93.33/32 192.168.192.168 pppoe-out1
[admin@MikroTik] > /interface print detail
Flags: D - dynamic, X - disabled, R - running, S - slave
0 R name="ether1-gateway" default-name="ether1" type="ether" mtu=1500 actual-mtu=1500 l2mtu=1598
max-l2mtu=4074 mac-address=D4:CA:6D:F5:29:74 fast-path=yes
1 R name="ether2-master-local" default-name="ether2" type="ether" mtu=1500 actual-mtu=1500
l2mtu=1598 max-l2mtu=4074 mac-address=D4:CA:6D:F5:29:75 fast-path=yes
2 S name="ether3-slave-local" default-name="ether3" type="ether" mtu=1500 actual-mtu=1500
l2mtu=1598 max-l2mtu=4074 mac-address=D4:CA:6D:F5:29:76 fast-path=yes
3 S name="ether4-slave-local" default-name="ether4" type="ether" mtu=1500 actual-mtu=1500
l2mtu=1598 max-l2mtu=4074 mac-address=D4:CA:6D:F5:29:77 fast-path=yes
4 S name="ether5-slave-local" default-name="ether5" type="ether" mtu=1500 actual-mtu=1500
l2mtu=1598 max-l2mtu=4074 mac-address=D4:CA:6D:F5:29:78 fast-path=yes
5 X name="wlan1" default-name="wlan1" type="wlan" mtu=1500 actual-mtu=1500 l2mtu=2290
mac-address=D4:CA:6D:F5:29:79 fast-path=no
6 R name="pppoe-out1" type="pppoe-out" mtu=1480 actual-mtu=1480 fast-path=no
7 R name="vlan2_1C" type="vlan" mtu=1500 actual-mtu=1500 l2mtu=1594 mac-address=D4:CA:6D:F5:29:75
fast-path=no
[admin@MikroTik] > /ip route print
Flags: X - disabled, A - active, D - dynamic,
C - connect, S - static, r - rip, b - bgp, o - ospf, m - mme,
B - blackhole, U - unreachable, P - prohibit
# DST-ADDRESS PREF-SRC GATEWAY DISTANCE
0 ADS 0.0.0.0/0 192.168.192.168 1
1 ADS 10.0.0.0/8 10.0.211.1 1
2 ADC 10.0.211.0/24 10.0.211.153 ether1-gateway 0
3 ADC 192.168.0.0/24 192.168.0.1 ether2-master-l... 0
4 ADC 192.168.2.0/24 192.168.2.1 vlan2_1C 0
5 ADC 192.168.192.168/32 194.44.93.33 pppoe-out1 0
