IPSec Site to Site VPN Configuration Series:
- Set Up IPSec Site to Site VPN Between Fortigate 60D (1) - Route-Based VPNs
- Set Up IPSec Site to Site VPN Between Fortigate 60D (2) - Policy-Based VPNs
- Set Up IPSec Site to Site VPN Between Fortigate 60D (3) - Concentrator and Troubleshooting
- Set Up IPSec Site to Site VPN Between Fortigate 60D (4) - SSL VPN
After tested policy based and route based IPSec vpn, this post will do a quick test FortiGate concentrator feature.
The VPN concentrator collects hub-and-spoke tunnels into a group.The concentrator allows VPN traffic to pass from one tunnel to the other through the FortiGate unit. The FortiGate unit functions as a concentrator, or hub, in a hub-and-spoke network.
If the VPN peer is a FortiGate unit functioning as the hub, or concentrator, it requires aVPN configuration connecting it to each spoke (AutoIKE phase 1 and 2 settings ormanual key settings, plus encrypt policies). It also requires a concentratorconfiguration that groups the hub-and-spoke tunnels together. The concentratorconfiguration defines the FortiGate unit as the hub in a hub-and-spoke network.If the VPN peer is one of the spokes, it requires a tunnel connecting it to the hub (butnot to the other spokes). It also requires policies that control its encrypted connectionsto the other spokes and its non-encrypted connections to other networks, such as theInternet.
Topology:
FW3 adds into the our previous topology used in route based and policy based vpn labs. FW3 will act as another spoke , same as FW1. FW2 will be the hub , or concentrator.
Photos:
Configuration:
1. @F3: Since there is a vpn tunnel built between F1 and F2 from previous lab, the first step is going to build another vpn tunnel between F2 and F3.
Create all local address object and remote address objects. Remote objects will include the protected network by F1 and F2.
Create a new rule to allow local network to remote networks with a new ipsec vpn tunnel.
Promote the new rule to the top of the list:
2. @F2. Create new policy rules with a new vpn tunnel betwee F2 and F3.
Create new remote network for F3.
Create a couple of new rules to allow local network to access remote F3's network using a new VPN tunnel F2-F3.
Since there are three local networks behind F2, three new rules will be created.
Note: There is no need to create rule to allow spoke traffic passing among them.
In the VPN - IPSec - Auto Key (IKE), F2-F3 vpn tunnle profile will be there.

At this moment, the tunnel between F2 and F3 is configured and should be up from IPSec monitoring tab.
3. Configure F1 for the traffic between two spokes , F1 and F3.
Add F3's protected network into Firewall Objects - Address - Addresses:

Add the new address object into firewall policy rule:
4. Configure concentrator on F2 hub
Create a new Conentrator from VPN- IPSec - Concentrator.
Give F1-F2-F3 as the name, and select both hub-spoke vpn tunnel as the members:
5. Pint Test:
This is the test from F1's local network host 10.94.70.20. Before concentrator configured at F2, ping to 10.99.144.4 timed out.
As soon as Step 4's concentrator configuration done, ping immediately replied.
Tracert result from 10.94.70.20 to 10.99.144.4:
C:\Documents and Settings\test>tracert 10.99.144.4
Tracing route to 10.99.144.4 over a maximum of 30 hops
1 <1 ms <1 ms <1 ms 10.94.70.4
2 1 ms <1 ms <1 ms 10.94.17.8
3 1 ms 1 ms 1 ms 10.99.144.4
Trace complete.
Troubleshooting Commands:
FGT60D #
diagnose vpn tunnel statdev=0 tunnel=1 proxyid=1 sa=1 conc=0 up=1
FGT60D # diagnose vpn tunnel listlist all ipsec tunnel in vd 0------------------------------------------------------name=f1-f2 ver=1 serial=3 10.94.32.8:0->10.94.17.8:0 lgwy=static tun=tunnel mode =auto bound_if=5proxyid_num=1 child_num=0 refcnt=8 ilast=3 olast=3stat: rxp=8 txp=12 rxb=600 txb=720dpd: mode=active on=1 idle=5000ms retry=3 count=0 seqno=16517natt: mode=none draft=0 interval=0 remote_port=0proxyid=_f1-f2_tun_ proto=0 sa=1 ref=2 auto_negotiate=1 serial=1 src: 0:0.0.0.0/0.0.0.0:0 dst: 0:0.0.0.0/0.0.0.0:0 SA: ref=6 options=0000002f type=00 soft=0 mtu=1412 expire=399 replaywin=1024 s eqno=3 life: type=01 bytes=0/0 timeout=1777/1800 dec: spi=1935da05 esp=aes key=32 aa7f520b5457bc16f97c5cfc43483eb1c9b54f853def0 8213ca068506f9cb103 ah=sha1 key=20 b69c401862a7b6320d92e36b0d400f95320852a9 enc: spi=7b5dfde9 esp=aes key=32 0dbcde0df85b6d31dfdceded16314ff1a4ef9977e8fdb bed655ee9ddd0ccc80c ah=sha1 key=20 f6543bd37cfcbd5ccf881340f4b651940b34684d dec:pkts/bytes=1/60, enc:pkts/bytes=2/240 npu_flag=03 npu_rgwy=10.94.17.8 npu_lgwy=10.94.32.8 npu_selid=3FGT60D #
diag debug application ike 255FGT60D #
diag debug enableFGT60D # diaike 0: comes 10.94.32.8:500->10.94.17.8:500,ifindex=5....ike 0: IKEv1 exchange=Informational id=da8b0eb3b674cd8e/c0b55e04f98318f5:ca3cf88 1 len=92ike 0: in DA8B0EB3B674CD8EC0B55E04F98318F508100501CA3CF8810000005C85114C19CFD9A0 E3ECE0331A8A6134E1424AD7F8D516523A8D3421F260A17EFFAC75CD4FE3A283CD02832C07B5636B 832E8E976E26A2376FA50F77D94B3D7620ike 0:f2-f1:104: dec DA8B0EB3B674CD8EC0B55E04F98318F508100501CA3CF8810000005C0B0 00018A23349616A88AF99FFEB71BDB181733E48597075000000200000000101108D28DA8B0EB3B67 4CD8EC0B55E04F98318F5000040B28799820191C3D307ike 0:f2-f1:104: notify msg received: R-U-THEREike 0:f2-f1:104: enc DA8B0EB3B674CD8EC0B55E04F98318F5081005013FB65E04000000540B0 00018A3902503765FF73A4AEB0F8D8DBCCC04A0E1BD63000000200000000101108D29DA8B0EB3B67 4CD8EC0B55E04F98318F5000040B2ike 0:f2-f1:104: out DA8B0EB3B674CD8EC0B55E04F98318F5081005013FB65E040000005C7E1 54F5BEE4DEB627A700A84B0CB3C0098B5962BFA6CED080EAC0B5BF0E406D2ED7C4EC054B05F97A20 4A1B812D946597958233BBBA2D5CB7A2ABA6EFB70B6CEike 0:f2-f1:104: sent IKE msg (R-U-THERE-ACK): 10.94.17.8:500->10.94.32.8:500, l en=92, id=da8b0eb3b674cd8e/c0b55e04f98318f5:3fb65e04ike 0:f2-f1: link is idle 5 10.94.17.8->10.94.32.8:0 dpd=1 seqno=40acike 0: comes 10.94.32.8:500->10.94.17.8:500,ifindex=5....ike 0: IKEv1 exchange=Informational id=da8b0eb3b674cd8e/c0b55e04f98318f5:60b967f2 len=92ike 0: in DA8B0EB3B674CD8EC0B55E04F98318F50810050160B967F20000005CB93CFF645F24AAD1702B89F758E4691C3A67210427BB251023BD3137C605D21D55585C435F25627A09A6242A5C4280EFA4B40E37AEF95224E33308D50465F0F9ike 0:f2-f1:104: dec DA8B0EB3B674CD8EC0B55E04F98318F50810050160B967F20000005C0B000018F7DB4421DE4D8FE837A092498CC9FC19144E120D000000200000000101108D28DA8B0EB3B674CD8EC0B55E04F98318F5000040B30821732F98702307ike 0:f2-f1:104: notify msg received: R-U-THEREike 0:f2-f1:104: enc DA8B0EB3B674CD8EC0B55E04F98318F508100501C910E3AF000000540B0000189A4BC0E8ACAAD4C3336B442280051149189B1574000000200000000101108D29DA8B0EB3B674CD8EC0B55E04F98318F5000040B3ike 0:f2-f1:104: out DA8B0EB3B674CD8EC0B55E04F98318F508100501C910E3AF0000005CEC41A52E04D7316299F3DBCE4005D26AE26AFE40F3ADA9ADBF24652041B6836EB942D004846F1B61F528980E9E3B9811CB6AC66B6C6DE439DF98CBC247BA4206ike 0:f2-f1:104: sent IKE msg (R-U-THERE-ACK): 10.94.17.8:500->10.94.32.8:500, len=92, id=da8b0eb3b674cd8e/c0b55e04f98318f5:c910e3afike 0:f2-f1: link is idle 5 10.94.17.8->10.94.32.8:0 dpd=1 seqno=40adike shrank heap by 122880 bytesike 0: comes 10.94.32.8:500->10.94.17.8:500,ifindex=5....ike 0: IKEv1 exchange=Informational id=da8b0eb3b674cd8e/c0b55e04f98318f5:60199215 len=92ike 0: in DA8B0EB3B674CD8EC0B55E04F98318F508100501601992150000005C202E2B7EC4FD78A9A47A7BAADC85BBBA1240E38168A3E1FF37450B96DA085B38096EFC3352AF7D457DF3D66674BA6848093BFD670234A7E9AC32297AF7A35F73ike 0:f2-f1:104: dec DA8B0EB3B674CD8EC0B55E04F98318F508100501601992150000005C0B0000188389BC2895680F8618F031B82FB9DA3FEB9C6769000000200000000101108D28DA8B0EB3B674CD8EC0B55E04F98318F5000040B4B478A703A2351A07ike 0:f2-f1:104: notify msg received: R-U-THEREike 0:f2-f1:104: enc DA8B0EB3B674CD8EC0B55E04F98318F5081005013AB0F2D6000000540B0000182AAE9F0D1D6178FF2826ABD38FCE35A17107CD42000000200000000101108D29DA8B0EB3B674CD8EC0B55E04F98318F5000040B4ike 0:f2-f1:104: out DA8B0EB3B674CD8EC0B55E04F98318F5081005013AB0F2D60000005C84CD92EF75CD2D72941E654D9C1F27D43038A5D56287736BABF6232A5744E413A2A4AC5FFEEA28AA1A51FAD159536748874E6D7F692750CC060C9619E727DD25ike 0:f2-f1:104: sent IKE msg (R-U-THERE-ACK): 10.94.17.8:500->10.94.32.8:500, len=92, id=da8b0eb3b674cd8e/c0b55e04f98318f5:3ab0f2d6ike 0:f2-f1: link is idle 5 10.94.17.8->10.94.32.8:0 dpd=1 seqno=40ae
FGT60D # diag debug reset
FGT60D # diag debug disable
Reference: