Clever Geek Handbook

Configuring an IPsec GRE tunnel between FortiOS 6.4.5 and RouterOS 6.48.1

The task was to unite the branches with the head office of the enterprise, where the server room was located. Fortigate 60E organized Internet access and acted as a firewall at the head office, in branches it acted as Internet access Mikrotik of various models. It was also necessary to configure dynamic OSPF routing and set up IPsec VPN tunnels with GRE. Having rummaged through the Internet, I found a couple of scattered articles about connecting Fortigate to microtic via IPsec VPN and GRE tunnel. I decided to combine this information in one of my articles in order to use it myself as a cheat sheet in the future. I will write about OSPF dynamic routing in the next article.





So the input data:





1. Head office of HQ FortiOS 6.4.5:





  • Public IP XXXX (network interface port1)





  • Internal network 192.168.111.0/24 (network interface port2)





  2. Branch of the enterprise Branch Mikrotik RouterOS 6.48.1:





  • Public IP YYYY ether1 network interface





  • Internal network 192.168.112.0/24 (ether2 network interface)





In fig. the connection of the main office and the branch is shown schematically.





Fortigate   mikrotik, , IPsec GRE. mikrotik . GRE,   Winbox   mikrotik Interfaces->GRE Tunnel->+( , ), : - Local Address Y.Y.Y.Y - Remote Address X.X.X.X "keepalive", . , , , . 10 10 . . ., 100 . , . GRE IPsec "Allow Fast Path", "Local Address:" IPsec. “IPsec Secret”, IPsec. , “IPsec Secret”.





IP GRE-. IP->Addresses->+





: 





/interface gre
add name=gre-tunnel1 keepalive=10s,10 local-address=Y.Y.Y.Y remote-address=X.X.X.X allow-fast-path=no
/ip address
add address=10.10.10.2/30 interface= gre-tunnel1

IPsec . phase-1, , IP , IP->IPsec->Profiles.





Peer phase-1, IP->IPsec->Peers. name Branch-HQ,   FortiGate HQ, profile1, phase-1.





IPsec phase-1.





phase-2, IPsec, IPsec (AH ESP), IPsec SA. IP->IPsec->Proposals





IPsec , IP->IPsec->Policies->General. Peer Branch-HQ, . Src. Address – mikrotik Y.Y.Y.Y, Dst. Address – FortiGate HQ X.X.X.X, GRE Protocol - 47.





Action Proposal – porposal1, .





:





 /ip ipsec profile
add dh-group=modp1536,modp2048 enc-algorithm=aes-256 hash-algorithm=sha256 lifetime=24h name=profile1
/ip ipsec peer
add address=X.X.X.X local-address=Y.Y.Y.Y name=Branch-HQ profile=profile1
/ip ipsec proposal
add auth-algorithms=sha256 enc-algorithms= aes-256-cbc lifetime=30m name=proposal1 
pfs-group=modp1536
/ip ipsec policy
add peer=Branch-HQ src-address= Y.Y.Y.Y dst-address= X.X.X.X protocol=47 proposal=proposal1
/ip ipsec identity
add peer=Branch-HQ secret=#!@BRaNCH@!#

 IP->Firewall->Filter Rules:





:





/ip firewall filter
add chain=input protocol=17 dst-port=500,4500 in-interface=ether1 action=accept

, :





/ip route
add dst-address=192.168.111.0/24 gateway=10.10.10.1

mikrotik , FortiGate.





FortiGate IPsec phase-1 :





config vpn ipsec phase1-interface
     edit HQA-Branch
         set peertype any
         set proposal aes256-sha256
         set dpd on-idle
         set dhgrp 5 14
         set auto-discovery-sender enable
         set remote-gw Y.Y.Y.Y
         set psksecret #!@BRaNCH@!#
         set dpd-retryinterval 5
     next
 end

  Phase-2 , “protocol 47” transport-mode ( )   GRE:





config vpn ipsec phase2-interface
    edit "HQA-Branch"
       set phase1name "HQA-Branch"
       set proposal aes256-sha256
       set dhgrp 5 14
       set auto-negotiate enable
       set encapsulation transport-mode
       set protocol 47
    next
end

GRE tunnel:





config system gre-tunnel
    edit "HQ-Branch"
        set interface "HQA-Branch"
        set remote-gw Y.Y.Y.Y
        set local-gw X.X.X.X
    next
end

IP IP : 





config system interface
     edit "HQ-Branch"
        set ip 10.10.10.1 255.255.255.255
        set remote-ip 10.10.10.2 255.255.255.252
        set interface "HQA-Branch"
    next
end

 GRE, IPsec, , . , , GRE IPsec. FortiOS IPsec .  «» IPsec (, IPsec ).





config firewall policy
     edit 2
         set name "Enable IPsec"
         set srcintf "HQA-Branch"
         set dstintf "HQA-Branch"
         set srcaddr "all"
         set dstaddr "all"
         set action accept
         set schedule "always"
         set service "ALL"
      next

  port2 GRE :





config firewall policy
     edit 3
        set name "GRE HQ->Branch"
        set srcintf "port2"
        set dstintf "HQ-Branch"
        set srcaddr "all"
        set dstaddr "all"
        set action accept
        set schedule "always"
        set service "ALL"
    next
    edit 4
        set name "GRE Branch->HQ"
        set srcintf "HQ-Branch"
        set dstintf "port2"
        set srcaddr "all"
        set dstaddr "all"
        set action accept
        set schedule "always"
        set service "ALL"
    next
end

GRE, GRE IPsec. , remote-gw gre-tunnel   IPsec. :





config router static
    edit 1
        set dst Y.Y.Y.Y/30
        set device "HQA-Branch"
    next

  





		edit 2
        set dst 192.168.112.0 255.255.255.0
        set device "HQ-Branch"
    next
end

And now IPsec and GRE have risen, traffic from the local network of the head office enters the local network of the branch office and vice versa.





Used the following articles:





1.   Fortinet





2.  Wiki Mikrotika





This is my second work, please do not kick too much.







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