环境：PIX515E-R防火墙，Win2000 server（英文版）安装ACS3.0做用户身份验证。
我把下午做试验的PIX配置贴出来：

PIX Version 6.3(1) // os 我用的 6.3 版本的，这个版本支持 IPSec VPN with NAT
interface ethernet0 auto
interface ethernet1 auto
nameif ethernet0 outside security0
nameif ethernet1 inside security100
enable password 8Ry2YjIyt7RRXU24 encrypted
passwd 2KFQnbNIdI.2KYOU encrypted
hostname ISSC-PIX515E-R
fixup protocol ftp 21
fixup protocol h323 h225 1720
fixup protocol h323 ras 1718-1719
fixup protocol http 80
fixup protocol ils 389
fixup protocol rsh 514
fixup protocol rtsp 554
fixup protocol sip 5060
fixup protocol sip udp 5060
fixup protocol skinny 2000
fixup protocol smtp 25
fixup protocol sqlnet 1521
names
access-list 101 permit ip 192.168.10.0 255.255.255.0 192.168.32.0 255.255.255.0
access-list 102 permit ip 192.168.10.0 255.255.255.0 192.168.32.0 255.255.255.0
access-list 104 permit icmp any any
pager lines 24
mtu outside 1500
mtu inside 1500
ip address outside 10.0.0.1 255.255.255.0
ip address inside 192.168.10.252 255.255.255.0
ip audit info action alarm
ip audit attack action alarm
ip local pool pccw 192.168.32.1-192.168.32.10
ip local pool pccw02 192.168.32.50
pdm history enable
arp timeout 14400
global (outside) 1 interface
nat (inside) 0 access-list 102 //对VPN连接的用户不经过NAT，这里的102对应上面的access-list 102
nat (inside) 1 192.168.10.0 255.255.255.0 0 0
access-group 104 in interface outside
route outside 0.0.0.0 0.0.0.0 202.108.48.181 1
timeout xlate 3:00:00
timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 rpc 0:10:00 h225 1:00:00
timeout h323 0:05:00 mgcp 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
aaa-server LOCAL protocol local
aaa-server partnerauth protocol radius
aaa-server partnerauth (inside) host 192.168.10.110 cisco123 timeout 10 //指定Radius服务器IP及key
aaa-server parnerauth protocol tacacs+
no snmp-server location
no snmp-server contact
snmp-server community public
no snmp-server enable traps
floodguard enable
sysopt connection permit-ipsec
crypto ipsec transform-set myset esp-des esp-md5-hmac
crypto dynamic-map dynmap 10 set transform-set myset
crypto map mymap 10 ipsec-isakmp dynamic dynmap
crypto map mymap client configuration address initiate
crypto map mymap client configuration address respond
crypto map mymap client authentication partnerauth //设置通过Radius进行用户身份验证
crypto map mymap interface outside
isakmp enable outside
isakmp identity address

isakmp nat-traversal 10 //这句就是允许NAT用户穿过PIX,在6.3中才新增的特性,例如解决局域网内NAT VPN拨号问题

isakmp policy 10 authentication pre-share
isakmp policy 10 encryption des
isakmp policy 10 hash md5
isakmp policy 10 group 2
isakmp policy 10 lifetime 86400

vpngroup vpn3000 address-pool pccw //以下我建了两个组，如果要为每个组分配一个固定IP的话，只有为每个用户建立一个Group了，哎，提出这样要求的客户简直是折磨人 ：（
vpngroup vpn3000 dns-server 202.96.134.133
vpngroup vpn3000 split-tunnel 102
vpngroup vpn3000 idle-time 1800
vpngroup vpn3000 password ********

vpngroup link address-pool pccw02
vpngroup link split-tunnel 102
vpngroup link idle-time 1800
vpngroup link password ********
telnet 192.168.32.0 255.255.255.0 outside
telnet 192.168.10.0 255.255.255.0 inside
telnet timeout 5
ssh timeout 5
console timeout 0
terminal width 80
Cryptochecksum:81630e6f8040b488f6c2e6c6ff872804
: end
[OK]