I would really recommend mpls rather than eoip.
Check
http://wiki.mikrotik.com/wiki/Manual:Ma ... uterBoards to check if your unit can handle the increased MTU
Refering to this page
http://wiki.mikrotik.com/wiki/Manual:Interface/EoIP eoip adds 42 bytes.
EoIP tunnel adds at least 42 byte overhead (8byte GRE + 14 byte Ethernet + 20 byte IP)
.
So if you increase you MTU on the eoip interface,
/interface eoip
add arp=enabled disabled=no l2mtu=65535 local-address=0.0.0.0 mac-address=FE:16:6A:47:42:D2 \
mtu=1542 name=eoip-tunnel1 remote-address=10.11.12.13 tunnel-id=100
And accordingly on you ethernet or wireless interface you should be able to transmitt a full 1500 frame across your eoip link without fragmentation.
/interface ethernet
set 2 arp=enabled auto-negotiation=yes disabled=no full-duplex=yes mac-address=\
02:18:19:0D:8C:C9 mtu=1542 name=ether3 speed=100Mbps
Check
http://wiki.mikrotik.com/wiki/Manual:Ma ... uterBoards to check if your unit can handle the increased MTU
As a last remark; a mpls + vpls link would need no more than 1526 with ordernary ethernet through the vpls and 1530 (with vlan tagged ethernet within the vpls)