AWS IPSec Tunnel success?

[OMatlock]

Hello folks,

I am so close to a successful AWS IPSec tunnel to my on premise (test) PA200 7.1.15.

I've downloaded the configuration file and using it as a guide, IPs, etc.

But I've been using this article to configure.  Main difference is I created a specific AWS zone like I do for all my IPSec Tunnels.  

http://www.richardyau.com/?p=240

I am able to access my on premise environment from the AWS EC2 instance, but not from on premise to AWS EC2 172.31.24.69.

I can't ping it or connect to the EC2 via RDP.  I see the ping tries in traffic log, but nothing shows up in packet trace for the RDP attempts.  <UPDATE>  Resolved after correcting IPs for PBF and RDP connection from LAN.

AWS has two VPN connections for redundancy.  I have both configured and active.

NOTE:  My Azure IPSec tunnel works great!

Configured tunnel interfaces according to AWS text document.

Configured tunnel monitor profile.

Configured PBF like referenced in documentation. <Corrected>

Configured Static routes for both VPN connections (different metric).

Created security rules in and out for AWS zone, open.

No additional NAT rules.  Just basic outbound internet rule to Untrust.  <corrected>

A ping from a VM inside my LAN ages out.  Nothing shows up when I try to RDP, including a packet trace, not even a drop file.

[OMatlock · Accepted solution]

I've resolved this, able to communicate to AWS EC2 back and forth.  I've corrected my screenshots above.

My configuration errors:

- PBF destination IPs were incorrect.

- NAT rule not needed.

- Was using incorrect IP when attempting to RDP from LAN resource.  That's why was not showing up in my log.

- Ping was not working because was not enabled on AWS security group.

[Junaid-Khan]

Does the inbound from AWS to On-Prem(resource) work ?

Are you using multiple-vr's ?

[OMatlock]

Sorry for my delayed response.  Yes, I did get AWS to On-Premise working.  I did not create a separate or second Virtual Router.  Just used my default.  Please let me know if I can help or provide more notes.  I still have this running...

[Huddlebuy]

Hi OMatlock

We have a similar issue from or end, for some reason we can't enable both tunnels at the same time- as it creates asymmetric routing. For e.g if traffic is sent from one tunnel, the PAN will reject any traffic from the other tunnel.

I see you have configured both tunnel interfaces to be part of the same zone. But we have used different zone, not sure if this is an issue too?

- we had to enable ECMP- later knew its not supported by AWS

Kind Regards

Anu

[jmeurer]

If you are refering to both tunnels going to the same VPG on the same firewall, yes, leave them in the same zone.  While they do not support ECMP, they also do not guarantee the same tunnel will be active always.  Putting the tunnels in the same zone will overcome IP Spoofing issue that creates.

[Huddlebuy]

Thanks for the suggestion

we will try that option as well. Also AWS suggested the below

Entering configuration mode [edit] # set deviceconfig setting tcp asymmetric-path bypass

# set deviceconfig setting session tcp-reject-non-syn no

# commit

We are quite hesitant to enable this gloabally, as this would also apply for non aws traffic. So enabled this via the zone protection profile - strickly for that zone.

[jmeurer]

I agree with your hesitation.  In general, routing asymmetry is bad for security visilbility.  I would not turn off reject no sync on your internet facing interfaces.  

[Huddlebuy]

thanks Jmeurer. I will try re-try this by moving to the same zone. Do you know or come across any step by step guide to the setting up process between the tunnels between on-prem palo and aws VPC's.

Kind regards

Anu

[jmeurer]

I typically recommend to start with this guide.

https://github.com/PaloAltoNetworks/aws-transit-vpc/blob/master/documentation/Transit_VPC_Manual_Bui...

Once you have your Transit Firewalls built, you can terminate the on-prem Firewalls on the Transit Firwalls with VPNs as if they are another spoke.  From there you can control policy locally or with Panorama, creating rules based on zones or subnets.