Cisco Anyconnect Vpn Ipv6



As of Fall 2018 the VPN supports IPv6. This page explains what that means and how IPv6 traffic is handled in the different profiles.

Tunnel All

The program openconnect connects to Cisco 'AnyConnect' VPN servers, which use standard TLS and DTLS protocols for data transport. The connection happens in two phases. First there is a simple HTTPS connection over which the user authenticates somehow - by using a. Cisco AnyConnect: IPv6 Access through IPv4 VPN Tunnel 2014-01-18 Cisco Systems, IPsec/VPN, IPv6 Cisco AnyConnect, Cisco ASA, IPv6, Remote Access VPN Johannes Weber When traveling to guest Wifis, e.g., at different customers sites, hotels, or public Wifis in general, I often have only IPv4 access to the Internet. This document provides a sample configuration for the Cisco Adaptive Security Appliance (ASA) to allow the Cisco AnyConnect Secure Mobility Client (referred to as 'AnyConnect' in the remainder of this document) to establish an SSL VPN tunnel over an IPv4 or IPv6 network.

Cisco Anyconnect Secure Mobility Client Ipv6

will tunnel both IPv4 and IPv6 traffic back to campus. All traffic, for all destinations. Even if your Internet Service provider (ISP) does not support IPv6, you will be able to use IPv6 through the connection to campus, as long as it is enabled on your computer.

Split Tunnel and Split Tunnel_No Private IP will work in different ways depending on what services your ISP provides. The IPv4 and IPv6 space considered 'campus traffic' is everything on the Guide to University of Illinois IP Spaces page listed under 'IP ranges that host systems and/or provide services for Urbana-Champaign'.
If your ISP has both IPv4 and IPv6 turned on for your network, then traffic for both IPv4 and IPv6 will be split, with campus traffic going to the VPN, and other traffic going over your ISP connection.
If your ISP has only IPv4 turned on for your network then traffic for IPv4 will be split, with campus IPv4 traffic going to the VPN, and other IPv4 traffic going over your ISP connection. All IPv6 traffic will be tunneled to campus, similar to Tunnel All, but just for your IPv6 traffic. The current version of the VPN no longer supports this behavior automatically, and currently in this scenario your IPv6 traffic for campus will go over the VPN, and if you have no IPv6 support from your ISP, IPv6 traffic not destined for campus will just not work.
A number of services like Facebook, Netflix, and others use IPv6 by default. In this case your traffic to those services will try IPv6 to your ISP and then fail. Most systems handle this gracefully and switch ever to IPv4 for anything IPv6 doesn't answer on, but some might not. To keep this from happening either your ISP needs to enable IPv6, or you need to disable IPv6 on your computer.
If your ISP has only IPv6 turned on for your network then traffic for IPv6 will be split, with campus IPv6 traffic going to the VPN, and other IPv6 traffic going over your ISP connection. All IPv4 traffic for campus IPv4 addresses will go over the VPN. IPv4 traffic to other addresses will be handled by your ISP however it normally handles IPv4 traffic on an IPv6 only network.
Not sure if your ISP is providing you IPv4, IPv6 or both? Before you connect to the VPN, go to https://www.whatismyip.com and see what IP address(es) you have. You can do it again after you connect to the VPN to be sure you got an IPv6 address.

Keywords:VPN Profiles cisco anyconnect split tunnel, tunnel all, duo, IPv6 IPv4Suggest keywordsDoc ID:84548
Owner:Debbie F.Group:University of Illinois Technology Services
Created:2018-08-07 11:46 CDTUpdated:2020-06-10 12:07 CDT
Sites:University of Illinois Technology Services
Feedback:54CommentSuggest a new documentSubscribe to changes

Topics Map > Networking > Virtual Private Networking (VPN)

IPv6 addresses and headers take up more space in the data packet than IPv4 addresses and headers do. Because of this some users are not able to connect to the VPN at all, and others can connect but can't download files, read email, or do other things that use large data payloads in their data packets. Adjusting the packet MTU to a lower value will make sure that there is enough space in the packet for the larger IPv6 headers.

This only affects customers that connect over IPv6. Cisco's AnyConnect software will always use IPv4 if it is available, so this will mostly affect customers using openconnect, or customers that only have IPv6 (which is rare). The default MTU for wireless and Ethernet is 1500 bytes. When using IPv6, especially if it is being tunneled, you'll need to set it down to between 1380 and 1450 depending on the your setup.

How can you tell if this is the problem?
  1. If you can't connect at all and your client just times out trying to connect (and is using IPv6 to get to the VPN*), then first check to see if you can ping6 the vpn (unix/Mac OS command is 'ping6 vpn.illinois.edu'). If that doesn't work, this is not the problem.
  2. If ping6 worked, then see if you can load the website over IPv6. https://vpn4g-1.gw.illinois.edu (or any of the VPNs). If it loads, this probably isn't the problem. If it loads, and the VPN connects, but then some things don't work, it might be the problem.
  3. If ping6 worked, but loading the website did not work, then there is a good chance this is your problem. Please try changing your MTU setting and see if that fixes the issue.
If you think this is the problem you are having, then you need to set your MTU size down to at lest 1450, possibly as low as 1380 to make everything work.
Mac OS:
Cisco anyconnect vpn for windows
  1. Go to Network settings
  2. lick on the interface being used for their network connection, if it is not already selected.
  3. Click on the 'Advanced' button.
  4. Click on the 'Hardware' tab.
  5. Change the 'Configure:' drop down to Manually.
  6. Change the 'MTU:' drop down to Custom.
  7. Type in 1380, click Okay, and then click Apply.

Windows 7, 8, and 10:

Follow the instructions from this website: https://support.zen.co.uk/kb/Knowledgebase/Changing-the-MTU-size-in-Windows-Vista-7-or-8 but replace 'ipv4' in all the commands with 'ipv6'.

Open a command prompt

  1. Click the Windows button on the task bar.
  2. Click All Programs.
  3. Click Accessories.
  4. Right-click on Command Prompt and click Run as administrator.
  5. If prompted click the Allow button.

Set the MTU size:

  1. Once the Command Prompt window is open follow the steps below to change the MTU size:

    1. Type netsh interface ipv6 show subinterface
    2. Press Enter.
    3. You will see a list of network interfaces.
    4. Type netsh interface ipv6 set subinterface “Local Area Connection” mtu=1450 store=persistent
      You should replace Local Area Connection with the name that appeared in the “Interface” column from steps 1-3.
    5. Press Enter.
    6. Restart you computer and then test again.

    If you still have problems after modifying the MTU repeat the above steps - replacing the numbers 1458 with 1430, or 1380 – restart the computer and test again.


Linux:

  1. In Linux there are multiple ways to do it. Here are two possibilities:
    1. If you are using openconnect, use the '-m 'option to specify the MTU like this
      1. openconnect -m 1380 -v vpn.illinois.edu
    2. Otherwise, after the vpn has connected, adjust the mtu on the tunnel interface that was created (in this example the tunnel was tun0)
      1. ifconfig tun0 mtu 1380

*How to tell if you are connected to the VPN over IPv6

First, check to see what IP address(es) your computer has. Go to https://www.whatismyip.com and see what it says. If you only have an IPv4 address, you can't be connecting over IPv6. If you only have an IPv6 address, then you are definitely connecting over IPv6.
If you have both an IPv4 and an IPv6 address and you aren't able to connect at all, it's hard for you to tell what address you're using to connect with to the VPN. As a general rule of thumb, if you are using the Cisco AnyConnect software it will always use IPv4 if it has one. If you are using openconnect or some other free client, it is likely using IPv6 - most open source software will try IPv6 first. If you absolutely need to know, contact the Technology Services Help Desk, they can look up your connection in the logs and see what IP address you connected with.
If you are able to connect, but things aren't working, you can see what the IP address of the server you're connected to is in the VPN application. This will let you know if it is IPv4 or IPv6. Open the statistics window (on Mac click on the graph icon on the connection window, on Windows click on the gear icon on the connection window, then select the statistics tab). Then look for the line named 'Server' to find the server's IP address.
If the address is in IPv6 format (up to 8 hex numbers, separated by colons - note that there can be fewer than 8 if there is a double colon - such as 2620:0:e00:3a::2) you are connected to the server over IPv6.

Cisco Anyconnect Vpn Ipv6 Download

If the address is in IPv4 notation (4 decimal numbers separated by periods such as 192.17.55.12) you are not connecting over IPv6.

Cisco Anyconnect Vpn Ipv6 Password






Comments are closed.