Remote-access Guide

cisco asa remote access vpn dns

by Kiara Kirlin II Published 2 years ago Updated 2 years ago
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This allows remote users to connect to the ASA and access the remote network through an IPsec

IPsec

Internet Protocol Security (IPsec) is a protocol suite for secure Internet Protocol (IP) communications by authenticating and encrypting each IP packet of a communication session. IPsec includes protocols for establishing mutual authentication between agents at the beginning …

encrypted tunnel. The remote user requires the Cisco VPN client software on his/her computer, once the connection is established the user will receive a private IP address from the ASA and has access to the network.

Full Answer

How to use AnyConnect VPN with Asa?

The remote user will open a web browser, enters the IP address of the ASA and then it will automatically download the anyconnect VPN client and establishes the connection. Here’s the topology that we will use:

How to use clientless WebVPN with Asa?

The clientless WebVPN method does not require a VPN client to be installed on the user’s computer. You just open your web browser, enter the IP address of the ASA and you will get access through a web portal. You only have limited access to a number of applications, for example: There is no full network access when you use clientless WebVPN.

How does the ASA support IPsec VPN?

The ASA supports IPsec LAN-to-LAN VPN connections for IPv4 or IPv6 using IKEv1 or IKEv2 and supports both inside and outside networks using the inner and outer IP headers. Interface—The device interface to enable or disable access.

How does the ASA assign IP addresses to remote users?

The ASA will assign IP addresses to all remote users that connect with the anyconnect VPN client. We’ll configure a pool with IP addresses for this: Remote users will get an IP address from the pool above, we’ll use IP address range 192.168.10.100 – 200.

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When remote users connect to our WebVPN, do they have to use HTTPS?

The following option is not required but useful, whenever someone accesses the ASA through HTTP then they will be redirected to HTTPS:

What is AnyConnect VPN?

Anyconnect is the replacement for the old Cisco VPN client and supports SSL and IKEv2 IPsec. When it comes to SSL, the ASA offers two SSL VPN modes: Clientless WebVPN. AnyConnect VPN. The clientless WebVPN method does not require a VPN client to be installed on the user’s computer. You just open your web browser, ...

What happens when a VPN user terminates a session?

Normally when the remote VPN user terminates the session, the anyconnect installer will be uninstalled. The anyconnect keep-installer installed command leaves it installed on the user’s computer.

What happens when you have an inbound access list?

When you have an inbound access-list on the outside interface then all your decrypted traffic from the SSL WebVPN has to match the inbound access-list. You can either create some permit statements for the decrypted traffic or you can just tell the ASA to let this traffic bypass the access-list:

Why does my client tries to download AnyConnect?

The client tries to download the Anyconnect automatically, this is because of the anyconnect ask none default anyconnect command that we used. Since we are using a self-signed certificate you will get the following error message:

What is the IP address of AnyConnect?

You can see that we received IP address 192.168.10.100 (the first IP address from the VPN pool). Anyconnect creates an additional interface, just like the legacy Cisco VPN client does.

What is an ayconnECT_policy?

The group policy is called “ANYCONNECT_POLICY” and it’s an internal group policy which means that we configure it locally on the ASA. An external group policy could be on a RADIUS server.

What version of ASA is AnyConnect?

The ASA supports the AnyConnect client firewall feature with ASA version 8.3 (1) or later, and ASDM version 6.3 (1) or later. This section describes how to configure the client firewall to allow access to local printers, and how to configure the client profile to use the firewall when the VPN connection fails.

What is DPD in ASA?

Dead Peer Detection (DPD) ensures that the ASA (gateway) or the client can quickly detect a condition where the peer is not responding, and the connection has failed. To enable dead peer detection (DPD) and set the frequency with which either the AnyConnect client or the ASA gateway performs DPD, do the following:

What is ACL AnyConnect_Client_Local_Print?

The ACL AnyConnect_Client_Local_Print is provided with ASDM to make it easy to configure the client firewall. When you choose that ACL for Public Network Rule in the Client Firewall pane of a group policy, that list contains the following ACEs:

Does ASA support LDAP?

The other parameters are valid for AAA servers that support such notification; that is, RADIUS, RADIUS with an NT server, and LDAP servers. The ASA ignores this command if RADIUS or LDAP authentication has not been configured.

Does AnyConnect SSL VPN work with IPsec?

This feature applies to connectivity between the ASA gateway and the AnyConnect SSL VPN Client only. It does not work with IPsec since DPD is based on the standards implementation that does not allow padding, and CLientless SSL VPN is not supported.

About Remote Access IPsec VPNs

Remote access VPNs allow users to connect to a central site through a secure connection over a TCP/IP network. The Internet Security Association and Key Management Protocol, also called IKE, is the negotiation protocol that lets the IPsec client on the remote PC and the ASA agree on how to build an IPsec Security Association.

Configuration Examples for Remote Access IPsec VPNs

The following example shows how to configure a remote access IPsec/IKEv1 VPN:

Configuration Examples for Standards-Based IPSec IKEv2 Remote Access VPN in Multiple-Context Mode

The following examples show how to configure ASA for Standards-based remote access IPsec/IKEv2 VPN in multi-context mode. The examples provide information for the System Context and User Context configurations respectively.

Configuration Examples for AnyConnect IPSec IKEv2 Remote Access VPN in Multiple-Context Mode

The following examples show how to configure ASA for AnyConnect remote access IPsec/IKEv2 VPN in multi-context mode. The examples provide information for the System Context and User Context configurations respectively.

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