How to configure Cisco ASA 5500 to work with the iPhone

Question

We have Cisco ASA 5510 (latest firmware version), and apparently, according to Cisco website it is compatible with new iPhone 3G's IPSec client:
http://www.cisco.com/en/US/docs/security/vpnclient/cisco_vpnclient/iPhone/2.0/connectivity/guide/iphone.html
We've setup our first iPhone properly. It connects fine to the network, shows VPN connection as active. Gets a private IP address. But does not let any traffic go to the internal network. We thought it might be DNS problem, but it cannot connect to Exchange server even when using IP address instead of DNS. No luck either.
After checking ASA logs, we found that iPhone goes through Phase 1 authentication correctly. But then gives some kind of error, mentioning "Attribute 5".
Has anybody been successful configuring ASA5500 series (in particular 5510) to be used with iPhone?
I noticed that many people are having these problems.
Please do not post to this topic if you have ANY OTHER Cisco device.
Cisco specifies that iPhone is compatible only with Cisco ASA 5500 Security Appliances and PIX Firewalls. Neither Cisco IOS VPN routers nor the VPN 3000 Series Concentrators support the iPhone VPN capabilities.
Let's keep this topic only for users of ASA 5500 series and PIX Firewalls.
It would be extremely helpful for a large number of users if somebody posted a list of settings for ASA5500 or PIX firewall that DO work with iPhone 2.0
Thank you!
Oleg R

Answer 1

We found the solution and a bug in Cisco firmware (seems to be a bug).
First of all, thanks to our Chief Systems Architect Seb, here is a config that worked for us on a Cisco 5520 (latest firmware).
access-list iphone_splitTunnelAcl standard permit <insert ip> <insert mask>
access-list iphone_splitTunnelAcl standard permit <insert ip> <insert mask>
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 transform-set iphone esp-3des esp-sha-hmac
crypto ipsec transform-set iphone mode transport
crypto ipsec transform-set ESP-3DES-SHA esp-3des esp-sha-hmac
crypto dynamic-map SYSTEMDEFAULT_CRYPTOMAP 65535 set pfs
crypto dynamic-map SYSTEMDEFAULT_CRYPTOMAP 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 iphone
crypto map outside_map 10 match address vpn
crypto map outside_map 10 set transform-set ESP-AES-256-SHA
crypto map outside_map 65535 ipsec-isakmp dynamic SYSTEMDEFAULT_CRYPTOMAP
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
crypto isakmp policy 20
 authentication pre-share
 encryption aes-256
 hash sha
 group 5
 lifetime 86400
crypto isakmp nat-traversal 20
group-policy iphone internal
group-policy iphone attributes
 wins-server value <insert ip> <insert ip>
 dns-server value <insert ip> <insert ip>
 vpn-tunnel-protocol IPSec
 ipsec-udp enable
 ipsec-udp-port 10000
 split-tunnel-policy tunnelspecified
 split-tunnel-network-list value iphone_splitTunnelAcl
 default-domain value <insert domain name>
tunnel-group iphone type remote-access
tunnel-group iphone general-attributes
 address-pool VPN-Pool
 authentication-server-group ActiveDirectory2
 default-group-policy iphone
tunnel-group iphone ipsec-attributes
 pre-shared-key <insert pre-shared key>
For iPhone you have to be using IPSec tab for configuration.
We tried to set up this config using the wizards, but it would not work.
Later it turned out that wizards by default set this setting:
"crypto isakmp nat-traversal 20"
equal to zero and there is no way to change it from the GUI.
Only after we changed it (increased the value from 0 to 20) through the command line the connection started working perfectly.
Please let me know how it works out for you.
Message was edited by: Rogik
Message was edited by: Rogik