03-15-2008 04:23 AM - edited 03-05-2019 09:46 PM
Hi,
i have a 2821 hooked up to my isp and my lan. the isp interface is configured with a ip only routed inside the isp network. the inside ip is routed worldwide. now when i try to connect to a network outside the isp directly from the router the package get dropped at the isp border router.
can i tell the ios to use insides interface ip for source ip of outgoing connection? normaly you dont need that but i have a webvpn running on the box and no outside http servers are reachable because of that.
any hints, regards Martin
03-15-2008 08:17 AM
If you mean you want to do something like ping from the router itself, you can specify a different address or interface for the source IP.
If you mean you have devices behind your router, and their addresses aren't valid, you'll need to activate NAT.
03-16-2008 04:11 AM
i want to initiate traffic from the router itself. not the networks behind the router, they are working well.
i know that i can choose the source address while using the ping command. but other traffic initiated by the router, in my case webvpn, should also have the inside ip as source addresse.
Basically it looks like this:
inet -> provider -[transfernet] ->
My webvpn is running on inside interface, when a client connects from the internet and initiates a http connection to the internet my router uses the outside ip as source address. but the transfernetwork is only routed inside the provider backbone. so the packages get dropped at the edge. my lan networks are routed propper, also from the internet.
Martin
03-16-2008 05:38 AM
Think I understand. Your problem is webvpn not permitting Internet traffic to work correctly to the remote client (bouncing off your internal network). I'm unfamiliar with webvpn, but its solution might be allowance of split tunneling from the remote host. However, I can see reasons for doing what you want, such as additional security to/from the Internet.
Again, unfamiliar with webvpn. If I've stated the problem correctly, and no one else responds on this forum, you might try a post in the VPN forum.
[edit]
PS:
Some other traffic types, from the router, can be told to have a specified source address.
e.g.
ip ftp source-interface
etc.
03-16-2008 06:17 AM
I think I can help with this. assuming
on your router, F0/0 is the ouside interface
and F0/1 is the inside interface. Here
we go:
int F0/1
ip address 192.168.1.1 255.255.255.0
ip nat inside
int F0/0
ip address 4.2.2.2
ip nat outside
ip nat inside source static tcp 192.168.1.1 80 interface FastEthernet0/0 80
ip nat inside source static tcp 192.168.1.1 443 interface FastEthernet0/0 443
Now Internet users will hit the outside
router IP and then router will translate
it into the internal IP.
Keep in mind that these things are designed
to work with hosts that sit behind the
router, NOT something that designs
to nat the outside ip of the router to
inside ip of the router, but you can
give that a try and see it its works for you.
CCIE Security
03-16-2008 08:18 AM
thanks for pointing out the direction, but i didnt get it 100%. can we play this through with real values:
! Inside / officaly routed ip network
int gi 0/0
ip address 60.16.112.225 255.255.255.224
ip address 60.16.112.229 255.255.255.224 secondary
! Outside / network to provider, only routed inside provider network
int gi 0/1
ip address 188.0.124.129 255.255.255.252
ip route 0.0.0.0 188.0.124.130
Webvpn is running on 60.16.112.229
Connections initiated from the router to outside should be rewritten to 60.16.112.229 while leaving int gi0/1.
Martin
03-16-2008 08:29 AM
"Connections initiated from the router to outside should be rewritten to 60.16.112.229 while leaving int gi0/1."
Who is the one initiating the connection first?
Must be some users over the internet right?
For example, user(s) come from 4.2.2.2 hitting ip 188.0.124.129 on port 80/443? is that a
a correct assumption?
If the router is the one initiates connection
first, then I don't think it is possible.
03-16-2008 08:50 AM
A Client on the internet authenticates at webvpn running on 112.229. Requesting a website 20.0.0.1, the router gets the website from 20.0.0.1 over his outside interface 188.0.124.129 and delivers the page to the client on the internet. Some sort of proxy. The router is the client for the webserver, initiating the connection to the webserver, rewriting the http content and sends it to to the client.
the client ip has not to be modified, it is the routers ip address while getting the http content from the internet.
Martin
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