im configuring eoip for my lan games
i would like to ask the proper way in forwarding gre port...i have dynamic isp and my modem is in route mode i need to port forward gre port so that i can ping on remote side

thanks in advance

try this:

/ip firewall nat
add action=dst-nat chain=dstnat comment="GRE Forwarding" disabled=no protocol=gre dst-address="YourGatewayAddress" to-addresses="YourInternalAddress"

im configuring eoip for my lan games
i would like to ask the proper way in forwarding gre port...i have dynamic isp and my modem is in route mode i need to port forward gre port so that i can ping on remote side

Just for your info: GRE is an IP protocol, not a specific port.
And that is why it can't be done on regular home routers via port forwarding configurations - there is usually an option VPN passthrough.

Anyway, dnat is achieved for a specific address as posted by scotthammersley.
For multiple outgoing sources with masquerade, or if your firewall is dropping unknown forward traffic by default, you also need a forwarding rule in your firewall setup:

thanks for the reply ...ended up with bridge

Good deal. Glad you figured it out.