Cisco ISR G2 to CheckPoint R80.30 IKEv1 VPN woes

I had previously done Cisco router to CheckPoint R80.30 gateway VPNs before without issue, but for whatever reason could not even establish phase 1 for this one. CheckPoint R80 VPN communities default to AES-256, SHA-1, Group 2, and 1-day timetime which is easy to match on the Cisco with this config:

crypto keyring mycheckpoint
 local-address GigabitEthernet0/0
 pre-shared-key address key abcdefghij1234567890
crypto isakmp policy 100
 encr aes 256
 authentication pre-share
 group 2
 hash sha          ! <--- default value
 lifetime 864000   ! <--- default value

After verifying connectivity, doing packet captures, and multiple reboots on on both ends, IKE simply would not come up. On the Cisco ISR, debug crypto isakmp wasn’t especially helpful:

Jun 18 11:06:17.085: ISAKMP: (0):purging SA., sa=3246F97C, delme=3246F97C
Jun 18 11:06:17.285: ISAKMP: (0):SA request profile is (NULL)
Jun 18 11:06:17.285: ISAKMP: (0):Created a peer struct for, peer port 500
Jun 18 11:06:17.285: ISAKMP: (0):New peer created peer = 0x2CE62C3C peer_handle = 0x80000005
Jun 18 11:06:17.285: ISAKMP: (0):Locking peer struct 0x2CE62C3C, refcount 1 for isakmp_initiator
Jun 18 11:06:17.285: ISAKMP: (0):local port 500, remote port 500
Jun 18 11:06:17.285: ISAKMP: (0):set new node 0 to QM_IDLE
Jun 18 11:06:17.285: ISAKMP: (0):insert sa successfully sa = 2CE620E8
Jun 18 11:06:17.285: ISAKMP: (0):Can not start Aggressive mode, trying Main mode.
Jun 18 11:06:17.285: ISAKMP: (0):found peer pre-shared key matching
Jun 18 11:06:17.285: ISAKMP: (0):constructed NAT-T vendor-rfc3947 ID
Jun 18 11:06:17.285: ISAKMP: (0):constructed NAT-T vendor-07 ID
Jun 18 11:06:17.285: ISAKMP: (0):constructed NAT-T vendor-03 ID
Jun 18 11:06:17.285: ISAKMP: (0):constructed NAT-T vendor-02 ID
Jun 18 11:06:17.285: ISAKMP: (0):Input = IKE_MESG_FROM_IPSEC, IKE_SA_REQ_MM
Jun 18 11:06:17.285: ISAKMP: (0):Old State = IKE_READY New State = IKE_I_MM1
Jun 18 11:06:17.285: ISAKMP: (0):beginning Main Mode exchange
Jun 18 11:06:17.285: ISAKMP-PAK: (0):sending packet to my_port 500 peer_port 500 (I) MM_NO_STATE
Jun 18 11:06:17.285: ISAKMP: (0):Sending an IKE IPv4 Packet.
Jun 18 11:06:17.369: ISAKMP-PAK: (0):received packet from dport 500 sport 500 Global (I) MM_NO_STATE
Jun 18 11:06:17.369: ISAKMP-ERROR: (0):Couldn't find node: message_id 2303169274
Jun 18 11:06:17.369: ISAKMP-ERROR: (0):(0): Unknown Input IKE_MESG_FROM_PEER, IKE_INFO_NOTIFY: state = IKE_I_MM1
Jun 18 11:06:17.369: ISAKMP: (0):Input = IKE_MESG_FROM_PEER, IKE_INFO_NOTIFY
Jun 18 11:06:17.369: ISAKMP: (0):Old State = IKE_I_MM1 New State = IKE_I_MM1

The CheckPoint gave a more “useful” error:

Main Mode Failed to match proposal: Transform: AES-256, SHA1, Group 2 (1024 bit); Reason: Wrong value for: Authentication Method

This seemed to imply the CheckPoint was expecting certificate-based authentication rather than PSK. In traditional mode, the gateway is set by default for certificate only. But it’s not clear how this is configured in newer versions.

After poking around settings for quite a while, I simply deleted the VPN community in CheckPoint SmartConsole and re-created it. The connection then popped up immediately.



VPN throughput Tests – Palo Alto VM-300 to GCP

I was doing a deep dive read of supported IKEv2 ciphers on GCP native VPNs today and thought I’d setup a quick lab to see which settings would provide best throughput. Lab setup was as follows:

  • Palo Alto VM-300 on m4.xlarge in us-east-2 (Ohio)
  • IKEv2 VPN to GCP us-east4 (N. Virginia)
  • Latency is a steady 13ms round trip time
  • AWS side test instance is t3.xlarge (4 vCPU / 16 GB RAM)
  • GCP side test instance is e2-standard-4 (4 vCPU / 16 GB RAM)
  • Both VMs running Ubuntu Linux 18.04.4
  • File is 500 MB binary file transfer via SCP

Throughput speeds (in Mbps) using DH Group 14 (2048-bit) PFS:

Encryption / HashSHA-512SHA-256SHA-1
AES-GCM 256-bit664668672
AES-GCM 128-bit648680704
AES-CBC 256-bit510516616
AES-CBC 192-bit492523624
AES-CBC 128-bit494573658
Average: 604 Mbps

Throughput speeds (in Mbps) using DH Group 5 (1536-bit) PFS:

Encryption / HashSHA-512SHA-256SHA-1
AES-GCM 256-bit700557571
AES-GCM 128-bit660676616
AES-CBC 256-bit464448656
AES-CBC 192-bit595528464
AES-CBC 128-bit605484587
Average: 574 Mbps

Throughput speeds (in Mbps) using DH Group 2 (1024-bit) PFS:

Encryption / HashSHA-512SHA-256SHA-1
AES-GCM 256-bit680626635
AES-GCM 128-bit672664680
AES-CBC 256-bit584452664
AES-CBC 192-bit536520664
AES-CBC 128-bit528502656
Average: 608 Mbps

Key Takeaways

GCP will prefer AES-CBC in their negotiations, but AES-GCM provides roughly 25% better throughput. So if throughput is paramount, be sure to have only AES-GCM in the IPSec profile.

If using AES-CBC, SHA-1, while deprecated, is 13% faster than SHA-256 and 25% faster than SHA-512. Since SAs are rebuilt every 3 hours, cracking isn’t as large a concern as in typical SHA-1 use cases.

DH Group does not affect speeds. May as well use the strongest mutually supported value, which is Group 14 (2048-bit). GCP does not support Elliptic Curve (Groups 19-21) so these couldn’t be tested. I would expect faster SA build times, but no change in transfer speeds.

Assuming SHA-256 and Group 14 PFS, this graph summarizes the results:

Reset admin password for CheckPoint IaaS Gateway in GCP or AWS

Someone changed the admin password, but we could still access the gateway via the SSH key. The processes for resetting the password, bypassing password history was quite easy:

Go to expert mode and generate a hashed string for password ‘ABCXYZ1234’

[Expert@checkpoint:0]# cpopenssl passwd -1 ABCXYZ1234

Then go back to regular CLI and apply the hashed password

set user admin password-hash $1$I54N3F1M$lk/zHvFaKRKXkUFoiEamq1exit

save config

That’s it. Logging in to GAIA as admin / ABCXYZ1234 will then work