Server ipsec.conf

config setup
    charondebug="ike 1, knl 1, cfg 0"
    uniqueids=never

conn ikev2
    auto=add
    compress=no
    type=tunnel
    keyexchange=ikev2
    fragmentation=yes
    forceencaps=yes
    ike=aes256gcm16-sha384-modp3072!
    esp=aes256gcm16-sha384-modp3072!
    dpdaction=clear
    dpddelay=300s
    rekey=no
    left=%any
    leftid=my-vpn.com
    leftcert=vpn-server.crt
    leftsendcert=always
    leftsubnet=0.0.0.0/0
    right=%any
    rightid=%any
    rightauth=eap-tls
    rightdns=1.1.1.1,1.0.0.1
    rightsourceip=10.0.2.0/24
    rightsendcert=never
    eap_identity=%identity

Server iptables -S

-P INPUT DROP
-P FORWARD DROP
-P OUTPUT DROP
-A INPUT -i lo -j ACCEPT
-A INPUT -p tcp -m tcp --dport 22 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 80 -m conntrack --ctstate NEW -m limit --limit 60/sec --limit-burst 20 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 443 -m conntrack --ctstate NEW -m limit --limit 60/sec --limit-burst 20 -j ACCEPT
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -p udp -m udp --dport 500 -j ACCEPT
-A INPUT -p udp -m udp --dport 4500 -j ACCEPT
-A FORWARD -s 10.0.2.0/24 -m policy --dir in --pol ipsec --proto esp -j ACCEPT
-A FORWARD -d 10.0.2.0/24 -m policy --dir out --pol ipsec --proto esp -j ACCEPT
-A OUTPUT -o lo -j ACCEPT
-A OUTPUT -p tcp -m tcp --dport 22 -m state --state NEW -j ACCEPT
-A OUTPUT -p tcp -m tcp --dport 53 -m state --state NEW -j ACCEPT
-A OUTPUT -p udp -m udp --dport 53 -m state --state NEW -j ACCEPT
-A OUTPUT -p tcp -m tcp --dport 80 -m state --state NEW -j ACCEPT
-A OUTPUT -p tcp -m tcp --dport 443 -m state --state NEW -j ACCEPT
-A OUTPUT -m state --state RELATED,ESTABLISHED -j ACCEPT

Client ipsec.conf

conn ikev2
    auto=start
    [email protected]
    leftsourceip=%config
    leftauth=eap-tls
    leftcert=vpn-client.crt
    right=my-vpn.com
    rightid=my-vpn.com
    rightauth=pubkey

Client iptables -S

-P INPUT DROP
-P FORWARD DROP
-P OUTPUT DROP
-A INPUT -i lo -j ACCEPT
-A INPUT -p tcp -m tcp --dport 22 -j ACCEPT
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A OUTPUT -o lo -j ACCEPT
-A OUTPUT -p tcp -m tcp --dport 53 -m state --state NEW -j ACCEPT
-A OUTPUT -p udp -m udp --dport 53 -m state --state NEW -j ACCEPT
-A OUTPUT -p tcp -m tcp --dport 80 -m state --state NEW -j ACCEPT
-A OUTPUT -p tcp -m tcp --dport 443 -m state --state NEW -j ACCEPT
-A OUTPUT -p udp -m udp --dport 500 -m state --state NEW -j ACCEPT
-A OUTPUT -p udp -m udp --dport 4500 -m state --state NEW -j ACCEPT
-A OUTPUT -m state --state RELATED,ESTABLISHED -j ACCEPT

The connection is established but when I run curl https://checkip.amazonaws.com, the returned IP is the client public IP vs the server public IP (expected). How can I route all traffic through the VPN?

Also, can’t SSH to client from server. Why?

Thanks!

Solution 1:

You want to configure rightsubet=0.0.0.0/0 on the client. The default is %dynamic, which resolves to the VPN server's IP address, so only traffic to that will then be tunneled.

Regarding SSH, you need to check the traffic counters (IPsec SAs, firewall rules) to see in which direction that traffic does or doesn't flow.