CloudGuard AWS HA to third party - VPN Tunnel Instability? BGP/ICMP traffic

CheckPointerXL — Sun, 23 Feb 2025 20:32:38 GMT

Hi all,

i'm facing some weird issue with a AWS cluster VPN to third party gateways.

At random times, also after 2 or 3 days, tunnel stucks and reset is needed.

From the capture i see that traffic is correctly encapsulated/decapsulated.

The cluster has external private ip of course.

Now i'm going to describe difference between working and not working tunnels:

WORKING TUNNEL

- tcpdump it shows packet sent/received on port 4500

- fw monitor it shows correctly bgp sent/received and echo request/reply received

NOT WORKING TUNNEL

- tcpdump it show that check point peer sent packet on 4500, remote peer answer with ESP packet (not encapsulated)

- fw monitor does not show reply when pinging ptp (it doesn't work), and bgp traffic sent it as id=0:

[vs_0][fw_2] vpnt29:O[44]: 192.168.14.1 -> 192.168.14.2 (TCP) len=52 id=0
TCP: 179 -> 60813 .S..A. seq=c8049c10 ack=7a7186a1

on working tunnels id=XXX is incremental

SO, the strange part is that VPN seems to be good (Phase1/2 UP and traffic is encrypted/decrypted), but BGP is down and i cannot ping the remote VTI.

vpn tu del it fix the issue

environment is r81.20 T98

Action taken:

Enabled offer_nat_t_initator, enabled dpd responder

any idea?

Re: CloudGuard AWS HA to third party - VPN Tunnel Instability? BGP/ICMP traffic

Jon_C — Wed, 26 Feb 2025 15:02:43 GMT

The obvious question always is if the tunnels were working fine before, what's changed? Patched recently?

Does tunnels have issues after pushing policy? (Global properties>AdvancedConfiguration>VPN Advanced Properties> VPN IKE properties> Turn on keep_IKE_SAs

For the VPN tunnel sharing are they configured for per subnet pair or per gateway pair.

With that said I would suggest contacting TAC if it's an option.

But regardless you should run a vpn debug before the issue presents itself, so that you can review the logs yourself and also be able to provide the information to TAC.

Best Practice - Run this command to start the VPN debug:

vpn debug trunc ALL=5

Best Practice - Run one of these commands to stop the VPN daemon debug:

vpn debug off

vpn debug truncoff

Run this command to see what file it logs to

run "vpn iked calc <peer IP>" on the relevant gateway

Example: vpn iked calc X.X.X.X (ExternalIP of Remote gateway)
vpn: Address X.X.X.X is handled by IKED 2

Files you can review and give to TAC

# $FWDIR/log/iked*
# $FWDIR/log/vpnd*

topic CloudGuard AWS HA to third party - VPN Tunnel Instability? BGP/ICMP traffic in Firewall and Security Management

CloudGuard AWS HA to third party - VPN Tunnel Instability? BGP/ICMP traffic

Re: CloudGuard AWS HA to third party - VPN Tunnel Instability? BGP/ICMP traffic