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Question

IPSEC VPN Starlink speed issues

Forum|Forum|3 years ago
June 5, 2023
23 replies
24692 views

Hi, I am using a Starlink Bussiness with public IP, to create a VPN between a Mikrotik to a FG1500D.

Without the VPN on the, a laptop connected to the Mikrotik on site can reach 250/50 Mbps (Minimum 80/15 Mbps); but with the VPN Stablished the speed down to maximim 15/10 Mbps.

The connection is

Laptop <--> Mikrotik RB960 <--> Starlink <--> Internet <--> F1500D <--> Internet

I tried changing the MTU, but nothing happen, I know that satellite system use tcp spoofing optimization techniques, but i cant confirm with starlink if thta feature is on his plattform and if this affect the VPN.

Somebody had the same issue?

Thanks in advanced

FortiGate

Show previous replies

Jorpoz

New Member

Hello @BillH_FTNT
I've done the test just now.
I get the same result with both config (udp and tcp with MSS 1440), the max speed I get is 20Mbps.

I suposse that is a starlink problem, but I cannot prove it.

Regards

BillH_FTNT

Staff

Hi @Jorpoz

Hi
The way to verify Starlink is to capture wireshark from your client, incoming firewall, and outgoing firewall. Then you check one packet flow in 3 files pcap to know where the drop packets are and where the retransmissions are. Therefore, you can prove that Starlink is not.

HTH

Bill

amuda

Staff

Hi,

Have you tried to put a switch in between?

AntonyChen

Explorer II

with ipsec vpnm You should try to set vpn tcp-mss on mikrotik to 1200 to see if this help.

Jorpoz

New Member

I could keep on testing, but I don't think they will solve the problem. so for me starlink works fine for web connections but not for vpn.

AntonyChen

Explorer II

tcp-mss settings for vpn not afftecs internet access performance, this very happen, when you create ipsec vpn some tcp-mss or mtu settings may affect the network speed like file transfer between local and remote network...
internet connection is perfect not mean it will provide enought condition for vpn .

dustink

New Member

We had the same speed issue when using starlink. Changed our fortigate policies from Proxy to Flow based and started getting full speeds. Hope this helps someone else.

amuda

Staff

Hi,

Have you tried to put a switch in between?

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