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Public subnet not reacheable with my aws client vpn endpoint

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Hello,

I'm encountering an issue with my VPN connection; I can access my EC2 instances within the private subnet via the VPN, but I'm unable to connect to instances in the public subnet.

I've tried adding authorization rules to permit access to the public subnet's destination CIDR. Additionally, I've configured the route table to redirect my VPN client CIDR to 'local'.

I believe it's a DNS issue, but I'm uncertain about how to fix it.

Thanks for help

Topics
Networking & Content DeliveryCompute
Tags
Amazon VPCAmazon EC2AWS Client VPN
Language
English
Alex
asked 4 months ago236 views
3 Answers
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Am I correct in understanding that you cannot access the private IP address of EC2 in the public subnet? Or does it mean that the public domain of EC2 is not accessible?

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EXPERT
Riku_Kobayashi
answered 4 months ago
  • Alex
    4 months ago

    So, my public domain of EC2 isn't accessible when I'm using client vpn endpoint

  • Riku_Kobayashi EXPERT
    4 months ago

    understood. Try adding a route to the NAT Gateway to the route table of the private subnet that the ClientVPN endpoint is associated with.

    By setting the route table of the private subnet to which the ClientVPN endpoint is linked as shown below, you will be able to access the public domain from NAT Gateway. https://repost.aws/knowledge-center/client-vpn-static-ip-address

    desttarget
    0.0.0.0/0NAT Gateway
    VPC CIDRlocal

    Alternatively, I think it is possible to perform DNS name resolution by setting up a split tunnel. By setting up a split tunnel, you can access the public domain without going through Client VPN. In this case, make sure to only configure the VPC CIDR in the AWS Client VPN route table. However, when using split tunnels, please note that setting "0.0.0.0/0" in the AWS Client VPN route table is not recommended. https://docs.aws.amazon.com/vpn/latest/clientvpn-admin/split-tunnel-vpn.html

  • Alex
    4 months ago

    Yes my private subnet has already NAT gateway (inside public subnet + elastic IP)

    With my VPN I can reach internet google.com etc.. but not my ec2 instance in public subnet.

    This is very strange...

  • Riku_Kobayashi EXPERT
    4 months ago

    Or, can I connect if I link the AWS Client VPN endpoint to a public subnet and configure it to go directly to the Internet from the Internet gateway? https://docs.aws.amazon.com/vpn/latest/clientvpn-admin/scenario-internet.html

  • Alex
    4 months ago

    Currently my endpoint vpn are associated to private subnet..

    Something strange, when I ping my domain (blabla.com) I don't have my dns A, i have something else, even for preprod.blabla.com I have host not found ...

    Looks like DNS isn't resolving when I am using VPN

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Any idea ? I'm still stuck on this topic ..

Alex
answered 3 months ago
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I need Expert AWS I think, 2 days i am on it and still nothing

Alex
answered 3 months ago

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