Hi, I noticed mismatch VLAN 1 in mikrotik and VLAN 1 in 3Com 5500G-EI.
I have 5 swishes 3com which is communicated in star with ip addresses in interface VLAN 1. When I put mikrotik CRS212 between two 3com switches and add vlan 1 tagged in mikrotik, I have no ping.
When add and enable VLAN 0 in mikrotik all is all right and ping is ok.
Is there entanglement or mismatch VLAN 0 and VLAN 1? 
It sounds like VLAN 1 is in untagged or native mode on the 3com switches. You will need to select another native vlan on the 3com switches or enable tagging of that VLAN.
No, port is trunk and all VLANS is tagged
Can you post the export of your CRS switch?
Ok, of course
@CRS 212 Mall Varna] > system export verbose
oct/30/2015 20:40:55 by RouterOS 6.32.2
software id = LLPZ-1YZS
/system logging action
set 0 memory-lines=1000 memory-stop-on-full=no name=memory target=memory
set 1 disk-file-count=2 disk-file-name=log disk-lines-per-file=1000 disk-stop-on-full=no name=disk target=disk
set 2 name=echo remember=yes target=echo
set 3 bsd-syslog=no name=remote remote=0.0.0.0 remote-port=514 src-address=0.0.0.0 syslog-facility=daemon syslog-severity=auto syslog-time-format=
bsd-syslog target=remote
/system clock
set time-zone-autodetect=yes time-zone-name=Europe/Sofia
/system clock manual
set dst-delta=+00:00 dst-end=“jan/01/1970 00:00:00” dst-start=“jan/01/1970 00:00:00” time-zone=+00:00
/system console
set [ find port=serial0 ] channel=0 disabled=no port=serial0 term=vt102
/system identity
set name=“CRS 212 Mall Varna”
/system leds
set 0 disabled=no interface=sfp1 leds=sfp1-led type=interface-activity
set 1 disabled=no interface=sfp2-vlan10 leds=sfp2-led type=interface-activity
set 2 disabled=no interface=sfp3-compa leds=sfp3-led type=interface-activity
set 3 disabled=no interface=sfp4 leds=sfp4-led type=interface-activity
set 4 disabled=no interface=sfp5 leds=sfp5-led type=interface-activity
set 5 disabled=no interface=sfp6 leds=sfp6-led type=interface-activity
set 6 disabled=no interface=sfp7 leds=sfp7-led type=interface-activity
set 7 disabled=no interface=sfp8 leds=sfp8-led type=interface-activity
set 8 disabled=no interface=sfp9-slave-na-ether1 leds=sfp9-led type=interface-activity
set 9 disabled=no interface=sfp10-slave-na-ether1 leds=sfp10-led type=interface-activity
set 10 disabled=no interface=sfpplus1 leds=sfpplus1-led1 type=interface-activity
set 11 disabled=no interface=sfpplus1 leds=sfpplus1-led2 type=interface-speed
set 12 disabled=no interface=ether1 leds=ether1-led type=interface-activity
/system logging
set 0 action=memory disabled=no prefix=“” topics=info
set 1 action=memory disabled=no prefix=“” topics=error
set 2 action=memory disabled=no prefix=“” topics=warning
set 3 action=echo disabled=no prefix=“” topics=critical
/system note
set note=“” show-at-login=yes
/system ntp client
set enabled=yes primary-ntp=46.47.81.47 secondary-ntp=212.233.218.5 server-dns-names=“”
/system resource irq
set 0 cpu=auto
set 1 cpu=auto
set 2 cpu=auto
set 3 cpu=auto
set 4 cpu=auto
/system routerboard settings
set baud-rate=115200 boot-delay=2s boot-device=nand-if-fail-then-ethernet boot-protocol=bootp cpu-frequency=4
enter-setup-on=any-key force-backup-booter=no protected-routerboot=disabled silent-boot=no
/system upgrade mirror
set check-interval=1d enabled=no primary-server=0.0.0.0 secondary-server=0.0.0.0 user=“”
/system watchdog
set auto-send-supout=no automatic-supout=yes no-ping-delay=5m watch-address=none watchdog-timer=yes