VPN between Checkpoint 4.1 and Cisco PIX

[lengoo]

Hi guys
I've got most of this set up and on my side (Checkpoint), I can see the two firewalls exchanging keys.
However, when I try to connect to the remote VPN, I see my packets going out but nought comes back and hence I'm not able to connect.
This means that either my Cisco router or the remote router is blocking something. So I temporarily turned off my inbound and outbound access lists and tried to connect again. Again.. nothing... which makes me think that it is the router at the remote end. I'm going to get them to try dropping the access lists as I have.
Seeing the two routers exchange keys sucessfully, is that enough for me to say that the configuration of the two firewalls is correct for VPN?
Does anyone know what I need to ensure they have on the other end in.. either their access lists to allow traffic or firewall. I'm wondering whether they are encrypting their ICMP packets through the VPN.. how can I check this?
Many thanks

 

[pplewis]

Maybe this will help, you do need a CCO account though:

http://www.cisco.com/en/US/customer...s_configuration_example09186a008009420f.shtml

 

[lengoo]

I missed this line on me PIX firewall

sysopt connection permit-ipsec

 

[pinger2k]

Hi guys,

not sure if this help. But this is a sample config for the cisco pix doing vpn with checkpoint.


Firewall-1 to PIX VPN using Preshared Secrets Example

PIX Configuration

The PIX is configured as follows:

PIX 515 with PIXOS 5.31.

The PIX is configured for this example as a onsite PIX which uses PAT to access Internet Services and a VPN for connectivity to either a hosting center or remote business location for a given company. There is no reason
why the roles of the two Firewall products can not be reversed.

Actual PIX configuration

nameif ethernet0 outside security0
nameif ethernet1 inside security100
nameif ethernet2 intf2 security10
nameif ethernet3 intf3 security15
nameif ethernet4 intf4 security20
nameif ethernet5 intf5 security25
enable password 8Ry2YjIyt7RRXU24 encrypted
passwd 2KFQnbNIdI.2KYOU encrypted
hostname pixfirewall
fixup protocol ftp 21
fixup protocol http 80
fixup protocol h323 1720
fixup protocol rsh 514
fixup protocol smtp 25
fixup protocol sqlnet 1521
fixup protocol sip 5060
names
name 192.1.1.1 PIX
name 172.16.2.168 RPIX
access-list 101 permit ip 172.16.0.0 255.255.0.0 10.0.1.0 255.255.255.0
access-list 101 permit ip 10.0.1.0 255.255.255.0 172.16.0.0 255.255.0.0
access-list 102 permit ip 10.0.1.0 255.255.255.0 172.16.0.0 255.255.0.0
pager lines 24
logging on
no logging timestamp
no logging standby
no logging console
no logging monitor
no logging buffered
logging trap debugging
no logging history
logging facility 20
logging queue 512
logging host inside 172.16.1.122
interface ethernet0 100full
interface ethernet1 100full
interface ethernet2 auto shutdown
interface ethernet3 auto shutdown
interface ethernet4 auto shutdown
interface ethernet5 auto shutdown
mtu outside 1500
mtu inside 1500
mtu intf2 1500
mtu intf3 1500
mtu intf4 1500
mtu intf5 1500
ip address outside PIX 255.255.255.0
ip address inside RPIX 255.255.0.0
ip address intf2 127.0.0.1 255.255.255.255
ip address intf3 127.0.0.1 255.255.255.255
ip address intf4 127.0.0.1 255.255.255.255
ip address intf5 127.0.0.1 255.255.255.255
ip audit info action alarm
ip audit attack action alarm
no failover
failover timeout 0:00:00
failover poll 15
failover ip address outside 0.0.0.0
failover ip address inside 0.0.0.0
failover ip address intf2 0.0.0.0
failover ip address intf3 0.0.0.0
failover ip address intf4 0.0.0.0
failover ip address intf5 0.0.0.0
arp timeout 14400
global (outside) 1 192.1.1.3
nat (inside) 0 access-list 101
nat (inside) 1 10.0.1.0 255.255.255.0 0 0
nat (inside) 1 0.0.0.0 0.0.0.0 0 0
access-group 102 in interface outside
conduit permit icmp any any
route outside 0.0.0.0 0.0.0.0 192.1.1.2 1
timeout xlate 3:00:00
timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 rpc 0:10:00 h323 0:05:00 sip 0:30:00 sip_media 0:02:00
timeout uauth 0:05:00 absolute
aaa-server TACACS+ protocol tacacs+
aaa-server RADIUS protocol radius
no snmp-server location
no snmp-server contact
snmp-server community public
no snmp-server enable traps
floodguard enable
sysopt connection permit-ipsec
no sysopt route dnat
crypto ipsec transform-set myset esp-des esp-sha-hmac
crypto map newmap 10 ipsec-isakmp
crypto map newmap 10 match address 101
crypto map newmap 10 set peer 192.1.1.2
crypto map newmap 10 set transform-set myset
crypto map newmap interface outside
isakmp enable outside
isakmp key cisco123 address 192.1.1.2 netmask 255.255.255.255
isakmp identity address
isakmp policy 10 authentication pre-share
isakmp policy 10 encryption des
isakmp policy 10 hash sha
isakmp policy 10 group 2
isakmp policy 10 lifetime 86400
telnet timeout 5
ssh timeout 5
terminal width 80

Note: Statements in bold are specific to VPN configuration

Nokia Configuration

The Nokia configuration is detailed below:

Nokia IP330, IPSO 3.3 and Checkpoint Firewall-1 4.1 Service Pack 3

The default static route points to 192.1.1.1

Actual Nokia Configuration

Objects Defined


Name Object Type IP Description

Behind-nokia Network 10.0.1.0 /24 Network behind the Nokia Firewall

Behind-pix Network 172.16.0.0 /16 Network behind the PIX

Nokia Firewall (internal gateway) 192.1.1.2 outside
(10.0.1.1 inside) Checkpoint Firewall Object

PIX Firewall (external gateway) 192.1.1.1 outside
(172.16.2.168 inside) PIX Firewall Object


Firewall Rulebase

Source Destination Service Action Description

Behind-nokia Behind-pix

Behind-pix Behind-Nokia Any Encrypt*

Any Any Any Drop Cleanup rule


*Note: Right Click on Encrypt and select the following:

Click IKE and select ESP as the Transform
Ensure that DES, SHA1 is selected.
The peer gateway can be any or a specified gateway

Firewall Encryption

Nokia Firewall Object

Select VPN window -> IKE -> Select DES -> SHA1 and key in preshared secret

Note: Support Aggressive Mode and Support Key Exchange for Subnets should be checked

PIX Firewall Object

Select VPN window -> IKE -> Select DES -> SHA1 and key in preshared secret

Note: Support Aggressive Mode and Support Key Exchange for Subnets should be checked

Windows Configuration

The Windows 2000 Clients in the testing were running Windows 2000 SP1

172.16.1.122 had a static route for network 10.0.1.0 /24 via the PIX inside interface 172.16.2.168

10.0.1.2 had a static route to network 172.16.0.0 /16 via the Nokia inside interface 10.0.1.1

Switch

A Cisco 1548 Switch was used for testing.

Tests conducted

Note: All tests were carried out with No existing connection

Test Result Comments
Icmp from 172.16.1.122 to 10.0.1.2 VPN created and worked
Icmp from 10.0.1.2 to 172.16.1.122 VPN created and worked
Net use from 172.16.1.122 to 10.0.1.2 VPN created and worked
Net use from 10.0.1.2 to 172.16.1.122 VPN created and worked
Policy installed during VPN session onto Nokia VPN tunnel remained stable

Note: When doing ICMP testing, a standard ping may timeout, a repeat ping
works due to time taken to create tunnel. This leads to the conclusion that
for some applications, a timeout increase is desirable.

Next Steps

Testing will be conducted using a pair of PIX Firewalls and a Nokia
VRRP cluster to ensure VPN stability within a HA environment.