Re: Networking issue: two routers with the same IP
* Stuart Henderson [EMAIL PROTECTED] [2007-05-01 17:25]: On 2007/05/01 17:02, Luca Corti wrote: Stuart Henderson wrote: It may be a hack, but 'virtual routing' is becoming more common as people need to connect networks on the same address range (e.g. with company mergers, or VPNs involving multiple organisations, where it would be challenging to renumber everything). Google: vrf nat. In this case you'd need VRF/MPLS support on OpenBSD, which is not there (and not planned it seems). IIRC you can now have multiple routing tables but cannot assign overlapping IP addresses to multiple interfaces by assigning them to different VRFs. you can *assign* them but I'm not sure whether or not you can get the rest of the system to work sensibly; that's why I'm not sure about doing this with rtable. you cannot put an interface to a different rtable yet. that had to happen so that all the arp stuff runs there instead of table 0, and only then you can have working overlapping address space on an openbsd box. I don't think there is too much left to make this actually, I wish somebody who actually needs that sits down for a few hours and codes that. reply-to is more likely to be successful since the return route information is attached to the PF state. it's certainly worth a try. nothing to be done here. ip-arp mapping will be fucked no matter what, and nothing can be done about it except renumbering or writing above mentionen code. -- Henning Brauer, [EMAIL PROTECTED], [EMAIL PROTECTED] BS Web Services, http://bsws.de Full-Service ISP - Secure Hosting, Mail and DNS Services Dedicated Servers, Rootservers, Application Hosting - Hamburg Amsterdam
Re: Networking issue: two routers with the same IP
You'd have to change your networking to have two distinct networks on the server to make this work. Ie, not 10.0.0.1 and 10.0.0.2, but rather 10.0.0.1 and 10.0.1.1 (or similar). Sure this will work, if you can change the server's IP Address. Unfortunately, you are looking for a hack for a bad network design (life's not perfect).
Re: Networking issue: two routers with the same IP
Frank, You seriously need to take care of that IP Address conflict. Contact whoever take care of the ADSL router and have them change the IP Address. One router between the second line will not resolve this problem since the two different network is needed to make routing possible. You will need two routers and the one next to server will need to NAT and probably PAT. An ugly hack. Is such a setup possible with OpenBSD? How would you do it? You will not be able to get it to work properly with any OS. The problem is your duplicate IP Addresses. RC On 4/30/07, Frank Denis [EMAIL PROTECTED] wrote: Hello, I currently have a remote server with a trivial network setup: [Server 10.0.0.1]-[NAT router 10.0.0.30 - external IP 1]-ADSL A second ADSL line and router have just been added. Unfortunately I have no control over the routers. Both routers come with the same IP address, it's why I have to setup something like this: 10.0.0.1|-[NAT router 10.0.0.30 - external IP 1]-ADSL 1 [Server | 10.0.0.2|-[NAT router 10.0.0.30 - external IP 2]-ADSL 2 Eacher router has a dedicated network interface on the server. I don't need bandwidth aggregation nor load balancing, but the server should be able to receive packets from external IP 1 and external IP 2. Is such a setup possible with OpenBSD? How would you do it? Thanks in advance for your help, -Frank.
Re: Networking issue: two routers with the same IP
Hi, On Tue, 01.05.2007 at 00:55:40 -0600, rc [EMAIL PROTECTED] wrote: Address. One router between the second line will not resolve this problem since the two different network is needed to make routing possible. I'm not convinced, but instead think that one router put in between solves the problem. That's because this other router won't even (need to) know the other (same) network on the other ADSL device. 10.0.0.1|-[NAT router 10.0.0.30 - external IP 1]-ADSL 1 [Server | 10.0.0.2|-[NAT router 10.0.0.30 - external IP 2]-ADSL 2 Imho, the modified setup will look like this: +--- adsl router 1 -- Internet server +--- new router adsl router 2 -- Internet You'd have to change your networking to have two distinct networks on the server to make this work. Ie, not 10.0.0.1 and 10.0.0.2, but rather 10.0.0.1 and 10.0.1.1 (or similar). Then you'll probably have the problem left of how to ensure reliable connectivity and, maybe, how to push your packets out those lines where their counterparts arrive... But setting things up properly in the first place and not wasting a router for such a hack is preferrable. Best, --Toni++
Re: Networking issue: two routers with the same IP
On 2007/05/01 12:53, Toni Mueller wrote: I'm not convinced, but instead think that one router put in between solves the problem. That's because this other router won't even (need to) know the other (same) network on the other ADSL device. Right. I'm not sure it's needed at all though, I think there may be a way with reply-to or possibly rtable. It may be a hack, but 'virtual routing' is becoming more common as people need to connect networks on the same address range (e.g. with company mergers, or VPNs involving multiple organisations, where it would be challenging to renumber everything). Google: vrf nat.
Re: Networking issue: two routers with the same IP
Stuart Henderson wrote: It may be a hack, but 'virtual routing' is becoming more common as people need to connect networks on the same address range (e.g. with company mergers, or VPNs involving multiple organisations, where it would be challenging to renumber everything). Google: vrf nat. In this case you'd need VRF/MPLS support on OpenBSD, which is not there (and not planned it seems). IIRC you can now have multiple routing tables but cannot assign overlapping IP addresses to multiple interfaces by assigning them to different VRFs. IMHO in this simple scenario it's much better to obtain a simple LAN IP address change from the ISP. ciao Luca
