From owner-freebsd-hackers Sat Sep 28 16:35:32 2002 Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id E6E1737B404 for ; Sat, 28 Sep 2002 16:35:28 -0700 (PDT) Received: from boreas.isi.edu (boreas.isi.edu [128.9.160.161]) by mx1.FreeBSD.org (Postfix) with ESMTP id 2356543E42 for ; Sat, 28 Sep 2002 16:35:28 -0700 (PDT) (envelope-from larse@ISI.EDU) Received: from isi.edu (nik.isi.edu [128.9.168.58]) by boreas.isi.edu (8.11.6/8.11.2) with ESMTP id g8SNZQC04399; Sat, 28 Sep 2002 16:35:26 -0700 (PDT) Message-ID: <3D963CBE.4080803@isi.edu> Date: Sat, 28 Sep 2002 16:35:26 -0700 From: Lars Eggert User-Agent: Mozilla/5.0 (X11; U; Linux i386; en-US; rv:1.1) Gecko/20020826 X-Accept-Language: en-us, de-de MIME-Version: 1.0 To: Ian Cartwright Cc: freebsd-hackers@freebsd.org Subject: Re: VPN Routing through gif (4) tunnel References: <006001c26723$f80775f0$6600a8c0@iansxp> Content-Type: multipart/signed; protocol="application/x-pkcs7-signature"; micalg=sha1; boundary="------------ms000303090701030604000901" Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG This is a cryptographically signed message in MIME format. --------------ms000303090701030604000901 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Ian, Ian Cartwright wrote: > > As I understand it, so long as the local tunnel endpoint is the external > interface of the local gateway, the encapsulated traffic should already > look like it is coming from the external interface and should not be > NATed (while the traffic inside the tunnel looks like it is coming from > my local RFC1918 network). Yes, the tunnel should go between the external addresses. But your NAT is still causing a problem. Consider this packet, send from a host on your local network to a host behind the remote tunnel end: | 192.168.0.10->200.200.200.20 | Data | When it reaches your local security gateway, there are two choices: (1) NAT gets the packet first, in which case it will be translated into | 100.100.100.1->200.200.200.20 | Data | (2) IPsec gets the packet first, in which case it will be encapsulated (## is the IPsec header): | 100.100.100.1->200.200.201.1 ## 192.168.0.10->200.200.200.20 | Data | If the second case occurs, your current SA should already cause this to happen. > It is also my understanding that IPFILTER > sees the traffic before the rest of the kernel (i.e. KAME) and may do > the NATing before it enters the IPSec tunnel, thus munging the works > entirely. This does not bode well. That is your problem, I think. IPfilter goes first, and your current SA does not match the NAT'ed packet. Try changing your SA so that the selector matches the packet under (1) above, so the final packet would look like | 100.100.100.1->200.200.201.1 ## 100.100.100.1->200.200.200.20 | Data | This is moderately ugly, since we're using the same address in the inner and outer header, but that's what you get for using NATs... Note that there's a good chance that the IPsec implementation on either side will balk at this. > Was my original assumption correct, that as long as the tunnel is > specified correctly in the SPD, that the routing will happen > automgically? Yes. Once the correct SA is in place, forwarding over the tunnel should happen. Lars -- Lars Eggert USC Information Sciences Institute --------------ms000303090701030604000901 Content-Type: application/x-pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" Content-Description: S/MIME Cryptographic Signature MIAGCSqGSIb3DQEHAqCAMIACAQExCzAJBgUrDgMCGgUAMIAGCSqGSIb3DQEHAQAAoIIJtjCC AzgwggKhoAMCAQICEGZFcrfMdPXPY3ZFhNAukQEwDQYJKoZIhvcNAQEEBQAwgdExCzAJBgNV BAYTAlpBMRUwEwYDVQQIEwxXZXN0ZXJuIENhcGUxEjAQBgNVBAcTCUNhcGUgVG93bjEaMBgG A1UEChMRVGhhd3RlIENvbnN1bHRpbmcxKDAmBgNVBAsTH0NlcnRpZmljYXRpb24gU2Vydmlj ZXMgRGl2aXNpb24xJDAiBgNVBAMTG1RoYXd0ZSBQZXJzb25hbCBGcmVlbWFpbCBDQTErMCkG CSqGSIb3DQEJARYccGVyc29uYWwtZnJlZW1haWxAdGhhd3RlLmNvbTAeFw0wMDA4MzAwMDAw MDBaFw0wNDA4MjcyMzU5NTlaMIGSMQswCQYDVQQGEwJaQTEVMBMGA1UECBMMV2VzdGVybiBD YXBlMRIwEAYDVQQHEwlDYXBlIFRvd24xDzANBgNVBAoTBlRoYXd0ZTEdMBsGA1UECxMUQ2Vy dGlmaWNhdGUgU2VydmljZXMxKDAmBgNVBAMTH1BlcnNvbmFsIEZyZWVtYWlsIFJTQSAyMDAw LjguMzAwgZ8wDQYJKoZIhvcNAQEBBQADgY0AMIGJAoGBAN4zMqZjxwklRT7SbngnZ4HF2ogZ gpcO40QpimM1Km1wPPrcrvfudG8wvDOQf/k0caCjbZjxw0+iZdsN+kvx1t1hpfmFzVWaNRqd knWoJ67Ycvm6AvbXsJHeHOmr4BgDqHxDQlBRh4M88Dm0m1SKE4f/s5udSWYALQmJ7JRr6aFp AgMBAAGjTjBMMCkGA1UdEQQiMCCkHjAcMRowGAYDVQQDExFQcml2YXRlTGFiZWwxLTI5NzAS BgNVHRMBAf8ECDAGAQH/AgEAMAsGA1UdDwQEAwIBBjANBgkqhkiG9w0BAQQFAAOBgQAxsUtH XfkBceX1U2xdedY9mMAmE2KBIqcS+CKV6BtJtyd7BDm6/ObyJOuR+r3sDSo491BVqGz3Da1M G7wD9LXrokefbKIMWI0xQgkRbLAaadErErJAXWr5edDqLiXdiuT82w0fnQLzWtvKPPZE6iZp h39Ins6ln+eE2MliYq0FxjCCAzkwggKioAMCAQICAwglQTANBgkqhkiG9w0BAQQFADCBkjEL MAkGA1UEBhMCWkExFTATBgNVBAgTDFdlc3Rlcm4gQ2FwZTESMBAGA1UEBxMJQ2FwZSBUb3du MQ8wDQYDVQQKEwZUaGF3dGUxHTAbBgNVBAsTFENlcnRpZmljYXRlIFNlcnZpY2VzMSgwJgYD VQQDEx9QZXJzb25hbCBGcmVlbWFpbCBSU0EgMjAwMC44LjMwMB4XDTAyMDgyNDE4NTMzOVoX DTAzMDgyNDE4NTMzOVowVDEPMA0GA1UEBBMGRWdnZXJ0MQ0wCwYDVQQqEwRMYXJzMRQwEgYD VQQDEwtMYXJzIEVnZ2VydDEcMBoGCSqGSIb3DQEJARYNbGFyc2VAaXNpLmVkdTCCASIwDQYJ KoZIhvcNAQEBBQADggEPADCCAQoCggEBANI2Rrt4ggaQ/IrOsDeOm2H4/R5FRIL6JjDY3StE aogp1r23WKniQ1Vj98Nu5WxlaZ3Iam3Jen5T66H8u7rtMNpK4qAeAGoBsVeyVr1+CTFeuv+m xCh7BvBJwhLdm0zDaoDT05YKYZaqtsT+F286FWJQg31Xtf+vTKLVVrHcsafnteyal2NEt7Ac yZZfjsVLwxp2Lq3cwYfRQRoo7/yCVzS7HsgM6jmbO4taEMo4yC2rpnUbWEUCDTaCYgpAXzAl oiNk7GDh0wz2s5ZSnHRvNSBMAjCmpNtSYHfXFI1ANwrrrHIJ7Ei83+XN32PWY4OPzO3iown9 VR+vM+8lNx9OX28CAwEAAaNWMFQwKgYFK2UBBAEEITAfAgEAMBowGAIBBAQTTDJ1TXlmZkJO VWJOSkpjZFoyczAYBgNVHREEETAPgQ1sYXJzZUBpc2kuZWR1MAwGA1UdEwEB/wQCMAAwDQYJ KoZIhvcNAQEEBQADgYEAXcrIlKmPLM/r8r3oz2ZLPLaT1AyMjYTZY2qq/R7SUtFa9BNlTIFh DG78QKfJ9lo2LMzTPQqMZgNLmj95GbNPI8P8OIq2K6MeCZWz08ROackqTFP6xWbIFIfXcBVR 1dZnDDyDKBBh05KkvyTPawSQyOBUeNBfQUyO4TE+3o58U8UwggM5MIICoqADAgECAgMIJUEw DQYJKoZIhvcNAQEEBQAwgZIxCzAJBgNVBAYTAlpBMRUwEwYDVQQIEwxXZXN0ZXJuIENhcGUx EjAQBgNVBAcTCUNhcGUgVG93bjEPMA0GA1UEChMGVGhhd3RlMR0wGwYDVQQLExRDZXJ0aWZp Y2F0ZSBTZXJ2aWNlczEoMCYGA1UEAxMfUGVyc29uYWwgRnJlZW1haWwgUlNBIDIwMDAuOC4z MDAeFw0wMjA4MjQxODUzMzlaFw0wMzA4MjQxODUzMzlaMFQxDzANBgNVBAQTBkVnZ2VydDEN MAsGA1UEKhMETGFyczEUMBIGA1UEAxMLTGFycyBFZ2dlcnQxHDAaBgkqhkiG9w0BCQEWDWxh cnNlQGlzaS5lZHUwggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAwggEKAoIBAQDSNka7eIIGkPyK zrA3jpth+P0eRUSC+iYw2N0rRGqIKda9t1ip4kNVY/fDbuVsZWmdyGptyXp+U+uh/Lu67TDa SuKgHgBqAbFXsla9fgkxXrr/psQoewbwScIS3ZtMw2qA09OWCmGWqrbE/hdvOhViUIN9V7X/ r0yi1Vax3LGn57XsmpdjRLewHMmWX47FS8Madi6t3MGH0UEaKO/8glc0ux7IDOo5mzuLWhDK OMgtq6Z1G1hFAg02gmIKQF8wJaIjZOxg4dMM9rOWUpx0bzUgTAIwpqTbUmB31xSNQDcK66xy CexIvN/lzd9j1mODj8zt4qMJ/VUfrzPvJTcfTl9vAgMBAAGjVjBUMCoGBStlAQQBBCEwHwIB ADAaMBgCAQQEE0wydU15ZmZCTlViTkpKY2RaMnMwGAYDVR0RBBEwD4ENbGFyc2VAaXNpLmVk dTAMBgNVHRMBAf8EAjAAMA0GCSqGSIb3DQEBBAUAA4GBAF3KyJSpjyzP6/K96M9mSzy2k9QM jI2E2WNqqv0e0lLRWvQTZUyBYQxu/ECnyfZaNizM0z0KjGYDS5o/eRmzTyPD/DiKtiujHgmV s9PETmnJKkxT+sVmyBSH13AVUdXWZww8gygQYdOSpL8kz2sEkMjgVHjQX0FMjuExPt6OfFPF MYIDJzCCAyMCAQEwgZowgZIxCzAJBgNVBAYTAlpBMRUwEwYDVQQIEwxXZXN0ZXJuIENhcGUx EjAQBgNVBAcTCUNhcGUgVG93bjEPMA0GA1UEChMGVGhhd3RlMR0wGwYDVQQLExRDZXJ0aWZp Y2F0ZSBTZXJ2aWNlczEoMCYGA1UEAxMfUGVyc29uYWwgRnJlZW1haWwgUlNBIDIwMDAuOC4z MAIDCCVBMAkGBSsOAwIaBQCgggFhMBgGCSqGSIb3DQEJAzELBgkqhkiG9w0BBwEwHAYJKoZI hvcNAQkFMQ8XDTAyMDkyODIzMzUyNlowIwYJKoZIhvcNAQkEMRYEFAUd9KlvNAc0WiuYNJiY 0xo2TkZnMFIGCSqGSIb3DQEJDzFFMEMwCgYIKoZIhvcNAwcwDgYIKoZIhvcNAwICAgCAMA0G CCqGSIb3DQMCAgFAMAcGBSsOAwIHMA0GCCqGSIb3DQMCAgEoMIGtBgsqhkiG9w0BCRACCzGB naCBmjCBkjELMAkGA1UEBhMCWkExFTATBgNVBAgTDFdlc3Rlcm4gQ2FwZTESMBAGA1UEBxMJ Q2FwZSBUb3duMQ8wDQYDVQQKEwZUaGF3dGUxHTAbBgNVBAsTFENlcnRpZmljYXRlIFNlcnZp Y2VzMSgwJgYDVQQDEx9QZXJzb25hbCBGcmVlbWFpbCBSU0EgMjAwMC44LjMwAgMIJUEwDQYJ KoZIhvcNAQEBBQAEggEAtzMREmCeue1KH70TH0MX8xAs5o2ziJxFMasAd1E0Lc0T0Kq9FGtB GerqFFKv/nqTAmmU88SDzT19/S+zgalCbbLE/3qZcernWgC11YHmSrK541XnhErXGLuvcHC8 z3P2HqoDHJcBfBAEPAIsNEfj22W4hOUwbhDHh4BGGSocSSze6ydQsSwSi2BviEg8tROlYoYn XLJNigx8SOYZUzkur44O8C/P+O1Aof8mEfvubmNU/BpsWA4UBDz65iww3yhRMgO6w4gXTOvI kzPcY/jT/lMb/CK025/1Spz8zUNs/TI8caFDf0TbCC46RIELDMt/Bv8CEHXX5LEHxqYbSEIr 7AAAAAAAAA== --------------ms000303090701030604000901-- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message