Go Premium for a chance to win a PS4. Enter to Win

x
?
Solved

ASA 8.4 - RAVPN Hairpinning to subnet across S2S VPN - Routing failed to locate next hop

Posted on 2013-06-29
9
Medium Priority
?
1,095 Views
Last Modified: 2014-02-20
Hi all!

Having a weird issue trying to get my RAVPN users to access resources at a remote site(corp).  RAVPN users (192.168.11.x) can access resources at the main site, and the main site can access resources at the remote site(192.168.101.x), but when I try to setup the hairpin connection so the RAVPN users can hit the remote site, I get a weird error in the logs - "Routing failed to locate next hop for ICMP from Outside:192.168.11.x to Inside:192.168.101.x"

My thought here is that it's trying to access the remote subnet via the Inside interface as shown in the error above "Inside:192.168.101.x", as my understanding is that since that subnet is on the other end of a site to site VPN, it should be accessed via the outside interface.  

Relevant sections of crypto map on main ASA:

crypto map Outside_map 1 match address Outside_cryptomap_1

access-list Outside_cryptomap_1 extended permit ip object-group DM_INLINE_NETWORK_3 object Corp-subnet 

object-group network DM_INLINE_NETWORK_3
 network-object object VPN-network

object network VPN-network
 subnet 192.168.11.0 255.255.255.0
 description VPN Subnet

Open in new window


Nat statements:
nat (Outside,Outside) source static VPN-network VPN-network destination static Corp-subnet Corp-subnet
nat (Inside,Outside) source static any any destination static VPN-network VPN-network

Open in new window


Access Lists:
access-list Outside_access_in extended permit ip object VPN-network object Corp-subnet 
access-list Outside_access_in extended permit ip object Corp-subnet object VPN-network 

Open in new window


Any ideas what I'm doing wrong?
0
Comment
Question by:valheru_m
  • 4
  • 4
9 Comments
 
LVL 22

Expert Comment

by:eeRoot
ID: 39287834
Do pings or trace routes from the firewall to 192.168.101.x connect properly?  If not, what path does the trace route reveal?
0
 
LVL 17

Expert Comment

by:Marius Gunnerud
ID: 39287868
I suspect that the traffic from the RAVPN is not being encrypted over the site to site vpn.  make sure the 192.168.11.x network is configured in the crypto ACL at both the corp and remote site also that there is an identity NAT / no nat statement for this traffic at both sites also.

would help to see the full sanitized configuration from both sites.
0
 
LVL 17

Expert Comment

by:Marius Gunnerud
ID: 39287870
Also make sure that routing is configured for the RAVPN at the remote site
0
Identify and Prevent Potential Cyber-threats

Become the white hat who helps safeguard our interconnected world. Transform your career future by earning your MS in Cybersecurity. WGU’s MSCSIA degree program was designed in collaboration with national intelligence organizations and IT industry leaders.

 
LVL 5

Author Comment

by:valheru_m
ID: 39288152
eeRoot:  Ping gets no response.  Traceroute doesnt even show a first hop.
0
 
LVL 5

Author Comment

by:valheru_m
ID: 39288155
Attached is the CoLo (Main site) config sanitized. Will sanitize corp and post shortly.
CoLoASA-sanitized.rtf
0
 
LVL 5

Author Comment

by:valheru_m
ID: 39288179
Corp config sanitized
CorpSanitized.txt
0
 
LVL 17

Expert Comment

by:Marius Gunnerud
ID: 39288498
it doesn't look like you have defined the RAVPN in the site to site cryptomap, but it is difficult to tell since a lot of the IPs are removed.  Are you using public IPs internally?

Also, The EasyVPN configuration at the corp office, I did not find a corresponding config on the remote office so I am assuming that is not being used here.

I would set up the site to site to include the 192.168.11.x network and add it to the no nat config at both ends.
0
 
LVL 5

Author Comment

by:valheru_m
ID: 39288852
On the corp site, users do have the ability to RAVPN there as well, but I'm trying to get rid of that for reasons that are a little too long-winded to expand upon here.  The RAVPN config at that site will be going away.  

There are no internal public IPs.  

As for the config, the relevant lines from the config I posted that address the nonat on both ends I *think* are these, but if I'm mistaken please feel free to correct me:

crypto map outside_map 2 match address outside_cryptomap
access-list outside_cryptomap extended permit ip 192.168.101.0 255.255.255.0 object-group DM_INLINE_NETWORK_2 
object-group network DM_INLINE_NETWORK_2
 <redacted> *** note that I only redacted the IPs not involved with the VPNNet, which is the VPN subnet from the CoLo ***
 network-object VPNNet 255.255.255.0

name 192.168.11.0 VPNNet description  VPN Network

Open in new window


The 192.168.101.0(Corp) and 192.168.11.0(CoLo VPN) nets are the only ones I'm concerned with at this time and everything else seems to be working fine.

On the CoLo config, I believe these are the relevant lines:

nat (any,any) source static VPN-network VPN-network destination static Corp-subnet Corp-subnet

crypto map Outside_map 1 match address Outside_cryptomap_1

access-list Outside_cryptomap_1 extended permit ip object-group DM_INLINE_NETWORK_3 object Corp-subnet 

object-group network DM_INLINE_NETWORK_3
 network-object object Dev-Network
 network-object object Prod-Network
 network-object object VPN-network

object network VPN-network
 subnet 192.168.11.0 255.255.255.0
 description VPN Subnet

Open in new window


Are you reccommending modifications to these lines specifically or...?

Thanks for your time!
0
 
LVL 17

Accepted Solution

by:
Marius Gunnerud earned 1500 total points
ID: 39291236
At the ColoASA remove the any any from the NAT statements and specify the exact subnets.  Something like the following

nat (Outside,Outside) source static VPN-network VPN-network destination static Corp-subnet Corp-subnet
0

Featured Post

Concerto's Cloud Advisory Services

Want to avoid the missteps to gaining all the benefits of the cloud? Learn more about the different assessment options from our Cloud Advisory team.

Question has a verified solution.

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

This program is used to assist in finding and resolving common problems with wireless connections.
This month, Experts Exchange’s free Course of the Month is focused on CompTIA IT Fundamentals.
Both in life and business – not all partnerships are created equal. Spend 30 short minutes with us to learn:   • Key questions to ask when considering a partnership to accelerate your business into the cloud • Pitfalls and mistakes other partners…
In this brief tutorial Pawel from AdRem Software explains how you can quickly find out which services are running on your network, or what are the IP addresses of servers responsible for each service. Software used is freeware NetCrunch Tools (https…

916 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