Cisco ASA 5505 - How to setup VPN-client access with PAT?

[sommar]

Hi,
We use a ASA with basic configurations for Internet access and as DHCP+FW for our company. We have now tried but failed to add VPN client access. During the last weeks we have read through a dozen of Cisco papers (such as Most Common L2L and Remote Access IPsec VPN Troubleshooting Solutions) – but we haven’t found a way to get access to the internal network from the VPN client side. We seem to have missed something fundamental…

Very thankful for advice!

We use PAT (we only have one real IP address: here mentioned as “200.100.100.103”). We cannot use tunnel splitting because of security reasons, all traffic shall go through the VPN tunnel to the ASA, and then to Internet or to the internal network (ASA inside/192.168.3.0).

The VPN configuration below is done by ADSM and the VPN Wizard were used. The Client (Cisco VPN) connects, login and the remote computer gets a IP-address from the pool (10.10.110.1-10.10.110.100).
We can then ping the VPN client from our 192.168.3.0 network side – but we can’t ping or access any computer from the VPN client side, and we can’t access Internet from the VPN client.

We have tried to add “crypto isakmp nat-traversal 20” or similar but the ASA don’t accept it… probably because of the PAT setup(?).

As said – we are very thankful for advice!

Regards,

mats



: Saved
:
ASA Version 8.3(1)
!
hostname ciscoasa
names
!
interface Vlan1
nameif inside
security-level 100
ip address 192.168.3.1 255.255.255.0
!
interface Vlan2
nameif outside
security-level 0
ip address 200.100.100.103 255.255.255.240
!
interface Ethernet0/0
switchport access vlan 2
!
interface Ethernet0/1
!
interface Ethernet0/2
!
interface Ethernet0/3
!
interface Ethernet0/4
!
interface Ethernet0/5
!
interface Ethernet0/6
!
interface Ethernet0/7
!
ftp mode passive
dns domain-lookup inside
dns server-group DefaultDNS
name-server 200.100.0.5
name-server 200.100.0.1
same-security-traffic permit intra-interface
object network obj_any
subnet 0.0.0.0 0.0.0.0
object network NETWORK_OBJ_10.10.110.0_25
subnet 10.10.110.0 255.255.255.128
pager lines 24
logging asdm informational
mtu inside 1500
mtu outside 1500
ip local pool OurRemoteAddressPool 10.10.110.1-10.10.110.100 mask 255.255.255.0
icmp unreachable rate-limit 1 burst-size 1
no asdm history enable
arp timeout 14400
nat (inside,outside) source dynamic any interface
!
object network obj_any
nat (inside,outside) dynamic interface
route outside 0.0.0.0 0.0.0.0 200.100.100.97 1
timeout xlate 3:00:00
timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 icmp 0:00:02
timeout sunrpc 0:10:00 h323 0:05:00 h225 1:00:00 mgcp 0:05:00 mgcp-pat 0:05:00
timeout sip 0:30:00 sip_media 0:02:00 sip-invite 0:03:00 sip-disconnect 0:02:00
timeout sip-provisional-media 0:02:00 uauth 0:05:00 absolute
timeout tcp-proxy-reassembly 0:01:00
dynamic-access-policy-record DfltAccessPolicy
http server enable
http 192.168.3.0 255.255.255.0 inside
http 10.10.110.0 255.255.255.0 inside
no snmp-server location
no snmp-server contact
snmp-server enable traps snmp authentication linkup linkdown coldstart
crypto ipsec transform-set ESP-3DES-SHA esp-3des esp-sha-hmac
crypto ipsec transform-set ESP-AES-256-MD5 esp-aes-256 esp-md5-hmac
crypto ipsec transform-set ESP-DES-SHA esp-des esp-sha-hmac
crypto ipsec transform-set ESP-DES-MD5 esp-des esp-md5-hmac
crypto ipsec transform-set ESP-AES-192-MD5 esp-aes-192 esp-md5-hmac
crypto ipsec transform-set ESP-3DES-MD5 esp-3des esp-md5-hmac
crypto ipsec transform-set ESP-AES-256-SHA esp-aes-256 esp-sha-hmac
crypto ipsec transform-set ESP-AES-128-SHA esp-aes esp-sha-hmac
crypto ipsec transform-set ESP-AES-192-SHA esp-aes-192 esp-sha-hmac
crypto ipsec transform-set ESP-AES-128-MD5 esp-aes esp-md5-hmac
crypto ipsec security-association lifetime seconds 28800
crypto ipsec security-association lifetime kilobytes 4608000
crypto dynamic-map SYSTEM_DEFAULT_CRYPTO_MAP 65535 set pfs group1
crypto dynamic-map SYSTEM_DEFAULT_CRYPTO_MAP 65535 set transform-set ESP-AES-128-SHA ESP-AES-128-MD5 ESP-AES-192-SHA ESP-AES-192-MD5 ESP-AES-256-SHA ESP-AES-256-MD5 ESP-3DES-SHA ESP-3DES-MD5 ESP-DES-SHA ESP-DES-MD5
crypto map outside_map 65535 ipsec-isakmp dynamic SYSTEM_DEFAULT_CRYPTO_MAP
crypto map outside_map interface outside
crypto isakmp enable outside
crypto isakmp policy 10
authentication pre-share
encryption 3des
hash sha
group 2
lifetime 86400
telnet timeout 5
ssh timeout 5
console timeout 0
management-access inside
dhcpd auto_config outside
!
dhcpd address 192.168.3.100-192.168.3.200 inside
dhcpd enable inside
!

threat-detection basic-threat
threat-detection statistics access-list
no threat-detection statistics tcp-intercept
webvpn
group-policy OurRemote internal
group-policy OurRemote attributes
dns-server value 200.100.0.5 200.100.0.1
vpn-tunnel-protocol IPSec
username stmaso password w8pB0qv9kFoLvha9 encrypted privilege 0
username stmaso attributes
vpn-group-policy OurRemote
tunnel-group OurRemote type remote-access
tunnel-group OurRemote general-attributes
address-pool OurRemoteAddressPool
default-group-policy OurRemote
tunnel-group OurRemote ipsec-attributes
pre-shared-key *****
!
class-map inspection_default
match default-inspection-traffic
!
!
policy-map type inspect dns preset_dns_map
parameters
message-length maximum client auto
message-length maximum 512
policy-map global_policy
class inspection_default
inspect dns preset_dns_map
inspect ftp
inspect h323 h225
inspect h323 ras
inspect rsh
inspect rtsp
inspect esmtp
inspect sqlnet
inspect skinny
inspect sunrpc
inspect xdmcp
inspect sip
inspect netbios
inspect tftp
inspect ip-options
!
service-policy global_policy global
prompt hostname context
Cryptochecksum:193cc7fa04e3509fce6d2f543a25ec21
: end
no asdm history enable

 

[hairlessupportmonkey]

doesnt the Cisco VPN client include a built in firewall? how about the windows firewall on the PC / client side?

ACSS - SME
General Geek

 

[sommar]

Thanks hairlessupportmonkey for your reply!

Yes, there is a "Stateful Firewall" in the Cisco client. It is by default off. I have tried on/off and also in different combinations with the Windows FW on/off on the client side... with the same result.

If same computer is connected to the ASA inside (192.168.3.0) then can we ping all other computers on the inside, and independet of what computer we place on the VPN client side we can ping them from the inside.

Regards,

Mats

 

[brianinms]

Doesn't look like you have nat exemption configured for the VPN subnet.

PS. I hate 8.3 code


object network obj-vpnpool

subnet 10.10.110.0 255.255.255.0

nat (inside,outside) 1 source static any any destination static obj-vpnpool obj-vpnpool