RE: VPN between multiple LANs
[email protected] Wed, 26 Jan 2005 13:57:20 -0800
| Newsgroups | gmane.comp.encryption.cipe |
|---|---|
| Message-ID | <[email protected]> |
Remember, each endpoint has TWO IP addresses associated with it: the "transport" IP address (usually a public IP address), and the "tunnel" IP address (usually a private IP address). The gateway systems need to be able to talk to each other, so the default route to the internet must exist, so that the transport IP addresses can talk to each other. Once you have that, you would set up a route to each LAN using your tunnel IP addresses. > -----Original Message----- > From: Tony Langdon (ATC) [SMTP:[email protected]] > Sent: Wednesday, January 26, 2005 1:44 PM > To: 'Mark'; 'Tony Langdon (ATC)'; '[email protected]' > Subject: RE: VPN between multiple LANs > > > If you use the same IP for all cipe adapters, what do you route by? > > I'm not sure I see the problem. Routing is based on _destination_ IP > address (let's leave policy routing aside for the moment, though that > isn't > an issue either in the real world), and all tunnels lead to different IPs > on > the remote end. > > Here's a real world example. 4 networks linked in total, 3 CIPE links > between each of the remote network and the local network. In all cases, > the > CIPE devices are using the same IP address. > > I've added some comments > > Kernel IP routing table > Destination Gateway Genmask Flags Metric Ref Use > Iface > > Host routes to remote tunnel endpoints. > 192.168.7.1 0.0.0.0 255.255.255.255 UH 0 0 0 > cipcb2 > 10.200.200.2 0.0.0.0 255.255.255.255 UH 0 0 0 > cipcb0 > 192.168.181.1 0.0.0.0 255.255.255.255 UH 0 0 0 > cipcb1 > > Network routes for cipcb0 > 202.12.87.160 10.200.200.2 255.255.255.248 UG 0 0 0 > cipcb0 > 202.12.87.152 10.200.200.2 255.255.255.248 UG 0 0 0 > cipcb0 > > Local LAN routes > 192.168.15.0 0.0.0.0 255.255.255.128 U 0 0 0 > eth0 > 192.168.15.128 0.0.0.0 255.255.255.128 U 0 0 0 > eth0 > > Network route for cipcb1 > 192.168.181.0 192.168.181.1 255.255.255.0 UG 0 0 0 > cipcb1 > > Network route to ISP > 211.28.37.0 0.0.0.0 255.255.255.0 U 0 0 0 > eth1 > > Linux seems to setup an autoconfig route for some reason.. > 169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 > eth1 > > Network route for cipcb2 > 192.168.0.0 192.168.7.1 255.255.0.0 UG 0 0 0 > cipcb2 > > Looopback > 127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo > > Default route (Internet) > 0.0.0.0 211.28.37.1 0.0.0.0 UG 0 0 0 > eth1 > > Oh, and the interfaces... > > OK, the first one is using an oddball address, but that's because it's > linked to a Windows host on the far end, which had to work that way, not > because I had routing issues on my end. > > cipcb0 Link encap:IPIP Tunnel HWaddr > inet addr:10.200.200.1 P-t-P:10.200.200.2 Mask:255.255.255.255 > UP POINTOPOINT NOTRAILERS RUNNING NOARP MTU:1442 Metric:1 > RX packets:0 errors:0 dropped:0 overruns:0 frame:0 > TX packets:4315 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:100 > RX bytes:0 (0.0 b) TX bytes:465732 (454.8 Kb) > > The rest use the same IP as eth0 > > cipcb1 Link encap:IPIP Tunnel HWaddr > inet addr:192.168.15.1 P-t-P:192.168.181.1 > Mask:255.255.255.255 > UP POINTOPOINT NOTRAILERS RUNNING NOARP MTU:1442 Metric:1 > RX packets:155401 errors:1 dropped:0 overruns:0 frame:1 > TX packets:167960 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:100 > RX bytes:12743584 (12.1 Mb) TX bytes:22187936 (21.1 Mb) > > cipcb2 Link encap:IPIP Tunnel HWaddr > inet addr:192.168.15.1 P-t-P:192.168.7.1 Mask:255.255.255.255 > UP POINTOPOINT NOTRAILERS RUNNING NOARP MTU:1442 Metric:1 > RX packets:2716998 errors:1409 dropped:0 overruns:0 frame:1409 > TX packets:3038908 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:100 > RX bytes:460282800 (438.9 Mb) TX bytes:400079776 (381.5 Mb) > > And for reference.... > > eth0 Link encap:Ethernet HWaddr 00:E0:29:9D:BA:4F > inet addr:192.168.15.1 Bcast:192.168.15.127 > Mask:255.255.255.128 > inet6 addr: 2001:388:c027:1::1/64 Scope:Global > inet6 addr: fe80::2e0:29ff:fe9d:ba4f/64 Scope:Link > UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 > RX packets:5209146 errors:0 dropped:0 overruns:0 frame:0 > TX packets:5225013 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:100 > RX bytes:584746849 (557.6 Mb) TX bytes:1748568057 (1667.5 Mb) > Interrupt:9 Base address:0x9000 > > -- > Message sent by the [email protected] mailing list. > Unsubscribe: mail [email protected], "unsubscribe cipe-l" in body > Other commands available with "help" in body to the same address. > CIPE info and list archive: > <URL:http://sites.inka.de/~bigred/devel/cipe.html> -- Message sent by the [email protected] mailing list. Unsubscribe: mail [email protected], "unsubscribe cipe-l" in body Other commands available with "help" in body to the same address. CIPE info and list archive: <URL:http://sites.inka.de/~bigred/devel/cipe.html>