Hi Ashwini,
Yes. You are right. EXOS will not support L2-GRE mode.
https://gtacknowledge.extremenetworks.com/articles/Q_A/Does-EXOS-support-L2-GRE-tunneling
Please find the below sample configuration for L3-GRE:
create vlan inet configure vlan inet add port 24 configure vlan inet ipa 1.1.1.1/24 create vlan users configure vlan users add port 1 configure vlan users ipa 100.0.0.1/24 create tunnel mytunnel gre destination 1.1.1.2 source 1.1.1.1 configure tunnel "mytunnel" ipaddress 2.0.0.1/24 configure iproute add 200.0.0.0/24 2.0.0.2 enable ipforwarding
Please let us know if you have any further queries.
Regards,
Karthikeyan