Cisco SSL VPN Configuration

At the moment I play around with Cisco SSL VPN (WebVPN) and here some steps how to configured these on an Cisco ASA. SSL VPN is on one hand the Cisco Anyconnect client and on the other an Clientless SSL VPN over a portal what is running on the ASA.

I will not go into much detail here, it’s more basic configurations steps you need to configure to get it running.

For a basic set-up we need two network objects

object network inside-subnet  
  subnet 172.16.0.0 255.240.0.0  
  exit

object network sslvpn-subnet  
  subnet 172.31.250.0 255.255.255.0  
  exit

Then we define the DHCP pool for Anyconnect connections

ip local pool SSLVPNClientPool 172.31.250.1-172.31.250.250 mask 255.255.255.0

We also need to make sure that Anyconnect clients communication with their original IP address and for that we need the following nat statement

nat (inside,outside) source static inside-subnet inside-subnet destination static sslvpn-subnet sslvpn-subnet

Here you select the Anyconnect package what you need to upload to your flash before and enable webvpn on your outside interface

webvpn  
  anyconnect image disk0:/anyconnect-win-2.4.1012-k9.pkg 1  
  enable outside  
  anyconnect enable  
  exit

In the SSL VPN client policy we define name server, domain name and DHCP pool. We also define here Anyconnect with ssl-client and the portal with ssl-clientless

group-policy SSLVPNClientPolicy internal 
group-policy SSLVPNClientPolicy attributes  
  dns-server value 172.16.0.12  
  default-domain value domain.com  
  address-pools value SSLVPNClientPool  
  vpn-tunnel-protocol ssl-client ssl-clientless  
  exit

We configure an SSL VPN tunnel group for remote access and set default policy to the SSL VPN client policy we configured in the step before

tunnel-group SSLVPNClientProfile type remote-access 
tunnel-group SSLVPNClientProfile general-attributes  
  default-group-policy SSLVPNClientPolicy  
  exit

Next, we define an external aaa server in my example an Windows Active Directory

aaa-server ldap-group protocol ldap
  aaa-server ldap-group (inside) host 172.16.0.12   
  ldap-base-dn OU=Departments, OU=DE, OU=Company, DC=domain,DC=com   
  ldap-login-dn cn=LDAPReader, OU=ServiceAccounts, OU=Company, DC=domain, DC=com   
  ldap-login-password secretpassword   
  ldap-naming-attribute sAMAccountName   
  ldap-scope subtree   
  server-type microsoft   
  exit

After we configured the external aaa server we need to link that in the tunnel group

tunnel-group SSLVPNClientProfile webvpn-attributes  
  group-alias SSLVPNClient enable  
  authentication-server-group ldap-group  
  exit

One of the last steps we enable the tunnel group within webvpn and configure sysopt permit-vpn

webvpn  
  tunnel-group-list enable  
  exit
sysopt connection permit-vpn

With the following command you can enable NTLM for a whole subnet if you use Windows IIS and integrate authentication

auto-signon allow ip 172.16.0.0 255.255.255.0 auth-type ntlm

That’s it, quite easy and clear setup over the command line, you can also click yourself through the ASDM but it will definitively take longer.

Please share!

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