Solved

ASA Access list. Allow traffic back in to our network?

Posted on 2011-09-16
2
297 Views
Last Modified: 2012-05-12

We have two sites connected by VPN. Main 192.168.0.0/24 and Branch office (BO) 192.168.1.0/24

There is a single DNS domain for both sites (MS AD integrated), and a BIND server running our public DNS.

We have a webmail server at the main site, 192.168.0.4. that is accessible via port forwarding from the outside interface public IP, lets say 1.2.3.4

Externally everything works fine. Yay!

Internally, if I set the DNS entry for webmail.company.com on the internal DNS to 192.168.0.4 then the Branch office can't access webmail when the VPN is down (a business continuity requirement).

If I set it to 1.2.3.4 then I can't access webmail from the Main site. (obviously it's fine from the Branch office).

What rules do I need to put in place to allow the 192.168.0.0/24 subnet to access webmail?

Can this be done with a static route and a secondary IP on the webmail server, or should I be looking ot allow traffic out and then back in through nat?
0
Comment
Question by:Wibble_
2 Comments
 
LVL 18

Accepted Solution

by:
jmeggers earned 250 total points
ID: 36555347
First, your branch office is being NATed to some address when it goes out to the Internet.  So you can add an ACL on the head-end that permits DNS requests (or whatever other traffic is needed) from a source address of the NAT address (or subnet) from your remote office.  

But the underlying issue as I see it is if your VPN is down, it's probably because the ISP connection at one side or the other is down.  In which case, you're not going to be able to get traffic through anyway.  Your solution really only works if you're paying for a private WAN service (e.g., Verizon MPLS) as the primary path between sites, and using the VPN tunnel over the Internet as a backup.
0
 
LVL 7

Assisted Solution

by:CSorg
CSorg earned 250 total points
ID: 36557186
agreed, approach this "a business continuity requirement" from a different angle, dont try to beat the unbeatable. Make sure you have an inplace backup line which would re-setup a vpn connection in case the main line goes woosh.
0

Featured Post

How to improve team productivity

Quip adds documents, spreadsheets, and tasklists to your Slack experience
- Elevate ideas to Quip docs
- Share Quip docs in Slack
- Get notified of changes to your docs
- Available on iOS/Android/Desktop/Web
- Online/Offline

Join & Write a Comment

The Cisco RV042 router is a popular small network interfacing device that is often used as an internet gateway. Network administrators need to get at the management interface to make settings, change passwords, etc. This access is generally done usi…
Hi All,  Recently I have installed and configured a Sonicwall NS220 in the network as a firewall and Internet access gateway. All was working fine until users started reporting that they cannot use the Cisco VPN client to connect to the customer'…
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…

707 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

16 Experts available now in Live!

Get 1:1 Help Now