Solved

VPN Client Changes Resolved Address

Posted on 2014-03-02
9
399 Views
Last Modified: 2014-03-12
A few users have reported that their VPN Client changes the pre-configured address from X.X.X.X to X-X-X-X.provider.net. For example - from 1.1.1.1 to 1-1-1-1.provider.net, Does anyone have any idea why would that hapen?
0
Comment
Question by:Strinalena
  • 4
  • 4
9 Comments
 
LVL 20

Expert Comment

by:edster9999
ID: 39898575
Explain a little more.

Do you mean it changes their internet address.
So when they connect up, they get the IP 10.20.30.40 and this then shows up later as 10-20-30-40.provider.net ?
Or do you mean it changes addresses they are using - so they go to a web address of 10.20.30.40....and that changes ?

If it is there address that changes - is it their real public IP (on their home network) like 192.168.x.x that gets changed or the one they get from your VPN

...or... something totally different ?
0
 
LVL 57

Expert Comment

by:giltjr
ID: 39899429
1-1-1-1.provider.net is not an IP address, that could be a host name, but IP addresses are numbers.
0
 

Author Comment

by:Strinalena
ID: 39899747
Hi,

Thanks for the replies. The issue is on the actual VPN client - When the users opens the Cisco Any Connect client - instead of them getting the normal 1.1.1.1 address in the "Connect To" Field, they get 1-1-1-1.provider.net. So the address of the Firewall to terminate the connection changes for some reason.
0
 
LVL 57

Expert Comment

by:giltjr
ID: 39899787
Still confused.  IP Addresses can not have letters in them.

Is the 1.1.1.1 your public IP address?

If they click on connect, does it work?
0
VMware Disaster Recovery and Data Protection

In this expert guide, you’ll learn about the components of a Modern Data Center. You will use cases for the value-added capabilities of Veeam®, including combining backup and replication for VMware disaster recovery and using replication for data center migration.

 

Author Comment

by:Strinalena
ID: 39899941
No - the Public ip is 87.224.XXX.XXX but when the users open the VPN client (You know - when you just double-click it) - instead of it showing the above ip address - it shows 87-224-XXX-XXX.name of the provider.net. The user has been able to use the client before but for some reason - at some point it gets changed and the user starts calling the helpdesk as there is no connection via the new strange address in the VPN client. It is not happenning regularly but there have been a few cases. Does this make any sense?
0
 
LVL 57

Expert Comment

by:giltjr
ID: 39900206
It looks like something is doing a reverse lookup on the IP address of your VPN server and replacing the actual address with the name that is on the PTR record for the address.

It appears that if you have a ASA cluster setup with a specific redirection option, that can happen.

So:

Do you have a ASA cluster?

Do you have the option "redirect-fqdn enable" on your ASA cluster?

Look at the page below and search on "Enabling Redirection"


http://www.cisco.com/c/en/us/td/docs/security/asa/asa84/configuration/guide/asa_84_cli_config/vpn_params.html
0
 

Author Comment

by:Strinalena
ID: 39902550
No ASA Cluster. The only comand on the device i find strange is the sysopt norpoxyarp inside. REally strange ans do not think that the issue is with the ASA but looks to me to be with the user's laptops.
So their machines are using their ISP's DNS servers and for some reason, you are saying that they are performing reverse DNS instead of forward one.
0
 
LVL 57

Accepted Solution

by:
giltjr earned 500 total points
ID: 39903033
Yes, something is deciding to do a reverse look-up and fill in the server field with the host name that is returned.

It can't do a forward lookup.  Forward look-ups take a name and see what IP address that maps to.  Reverse look-ups take an IP address and find out what name it is mapped to.

Since you know the public IP address, you can issue the command:

     nslookup x.x.x.x

Where x.x.x.x is the  IP address of the VPN server and see what is returned.  You will want to try this from inside your network and from the Internet.  

It's really not that big of a deal.
0
 

Author Comment

by:Strinalena
ID: 39903240
I know - just annoying and it is not even our Firewall :-) Thanks for the replies
0

Featured Post

What Should I Do With This Threat Intelligence?

Are you wondering if you actually need threat intelligence? The answer is yes. We explain the basics for creating useful threat intelligence.

Join & Write a Comment

Suggested Solutions

Let’s list some of the technologies that enable smooth teleworking. 
When it comes to security, there are always trade-offs between security and convenience/ease of administration. This article examines some of the main pros and cons of using key authentication vs password authentication for hosting an SFTP server.
Get a first impression of how PRTG looks and learn how it works.   This video is a short introduction to PRTG, as an initial overview or as a quick start for new PRTG users.
This video gives you a great overview about bandwidth monitoring with SNMP and WMI with our network monitoring solution PRTG Network Monitor (https://www.paessler.com/prtg). If you're looking for how to monitor bandwidth using netflow or packet s…

744 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

11 Experts available now in Live!

Get 1:1 Help Now