Solved

Cisco ASA 5505 with DSL

Posted on 2011-02-14
3
2,066 Views
Last Modified: 2012-05-11
I have just had PPPoE DSL service installed at a remote office location. The DSL modem/router is a Motorola Netopia 3000. The DSL service has five static IP addresses: x.x.x.241-245, with .246 as the gateway, and 255.255.255.248 as the mask. The DSL service is working properly; when I connect the DSL modem to the LAN with its DHCP server enabled, it leases addresses to the clients, and they are able to browse the web, etc.

Now, I have a Cisco ASA 5505 that I would like to use for a VPN connection to the main office.

In the past, I have dealt with only T1 and Cable, not DSL. With Cable, I would simply assign one of my public IP addresses to the outside interface on the ASA, assign a LAN address (e.g. 192.168.1.1) to the inside interface, and configure a static route using the service's gateway address -- and voilà! I'm in business.

Note: In the above scenarios, I have typically used internal DHCP and DNS servers. In this case, I have no server on the LAN; I would like to use the 5505 as a DHCP server, and point my clients to the ISP DNS servers.

So, I configured the ASA as noted above, enabling the DHCP server to hand out my ISP's assigned DNS servers. When I installed the ASA between the Netopia and my LAN switch, the DHCP server on the 5505 properly assigned everything to the clients on the LAN, but I had no DNS resolution (DNS server not reachable via nslookup) -- no traffic outbound at all, even bypassing DNS.

I have heard that DSL doesn't get along very will with Cisco equipment "out of the box", but having never worked with the two in tandem before, I'm not sure where to begin troubleshooting.

NAT? Bridging?

Thanks.

Steve
0
Comment
Question by:sf09er
3 Comments
 
LVL 6

Accepted Solution

by:
kuoh earned 500 total points
ID: 34893868
Have you contacted the ISP?  Usually the DSL modem is configured to provide the PPPOE credentials, but operates in bridge mode.  Then you simply configure the outside IP & GW on the ASA as usual.  You will also need to find out the ISP's DNS server IPs and enter them in the ASA's DHCP server options.

KuoH
0
 
LVL 34

Expert Comment

by:Istvan Kalmar
ID: 34894135
Did you enabled importing dns?

dhcpd auto_config outside
0
 

Author Closing Comment

by:sf09er
ID: 34901928
I simply had to disable DHCP and enable bridging on the DSL router, then connect the ASA, connect to the DSL using PPPoE, and I'm in business. Thanks.
0

Featured Post

Free Tool: IP Lookup

Get more info about an IP address or domain name, such as organization, abuse contacts and geolocation.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
cisco 2800 cannot ping lan 4 23
ASA Tunnel 18 42
Problems with replacment of Cisco 4510 2 24
ASA 5506X create a simple DMZ 4 26
From Cisco ASA version 8.3, the Network Address Translation (NAT) configuration has been completely redesigned and it may be helpful to have the syntax configuration for both at a glance. You may as well want to read official Cisco published AS…
I recently attended Cisco Live! in Las Vegas, a conference that boasted over 28,000 techies in attendance, and a week of hands-on learning hosted by a solid partner with which Concerto goes to market.  Every year, Cisco displays cutting-edge technol…
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…
As a trusted technology advisor to your customers you are likely getting the daily question of, ‘should I put this in the cloud?’ As customer demands for cloud services increases, companies will see a shift from traditional buying patterns to new…

789 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