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| Subject: | RE: PIX dhcprelay via IPSec. |
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| Date: | Fri, 17 Mar 2006 08:58:43 +0100 |
Hi Cosmin, Here are the relevant parts (things in caps are sanitized): REMOTE SITE PIX hostname REMOTE access-list outside_access_in permit icmp any interface outside echo-reply access-list outside_access_in permit ip any any access-list inside_access_out permit ip any any logging on logging buffered informational ip address outside REMOTE_OUTSIDE 255.255.255.240 ip address inside REMOTE_INSIDE 255.255.255.0 global (outside) 1 interface nat (inside) 1 0.0.0.0 0.0.0.0 0 0 access-group outside_access_in in interface outside access-group inside_access_out in interface inside route outside 0.0.0.0 0.0.0.0 CORRECT_STANDARD_GW 1 management-access inside dhcprelay server DHCP_IP outside dhcprelay enable inside vpnclient server GATEWAY_OUTSIDE vpnclient mode network-extension-mode vpnclient vpngroup GROUP password GROUP_PW vpnclient username USER password USER_PW vpnclient enable CENTRAL PIX hostname CENTRAL access-list outside_access_in permit icmp any interface outside echo-reply access-list inside_access_out permit ip any any access-list outside_access_in permit ip any any access-list inside_outbound_nat0_acl permit ip any REMOTE_INSIDE 255.255.255.0 access-list outside_cryptomap_dyn_20 permit ip any REMOTE_INSIDE 0 255.255.255.0 logging on logging buffered informational ip address outside GATEWAY_OUTSIDE 255.255.255.240 ip address inside GATEWAY_INSIDE 255.255.255.0 ip local pool REMOTE_POOL 10.180.248.0-10.180.248.255 global (outside) 1 interface nat (inside) 0 access-list inside_outbound_nat0_acl nat (inside) 1 0.0.0.0 0.0.0.0 0 0 access-group outside_access_in in interface outside access-group inside_access_in in interface outside route outside 0.0.0.0 0.0.0.0 CORRECT_STANDARD_GW 1 sysopt connection permit-ipsec crypto ipsec transform-set ESP-3DES-MD5 esp-3des esp-md5-hmac crypto dynamic-map outside_dyn_map 20 match address outside_cryptomap_dyn_20 crypto dynamic-map outside_dyn_map 20 set transform-set ESP-3DES-MD5 crypto map outside_map 65535 ipsec-isakmp dynamic outside_dyn_map crypto map outside_map client authentication LOCAL crypto map outside_map interface outside isakmp enable outside isakmp policy 20 authentication pre-share isakmp policy 20 encryption 3des isakmp policy 20 hash md5 isakmp policy 20 group 2 isakmp policy 20 lifetime 86400 vpngroup GROUP address-pool REMOTE_POOL vpngroup GROUP dns-server DNS vpngroup GROUP wins-server WINS vpngroup GROUP default-domain DOMAIN.TLD vpngroup GROUP idle-time 1800 vpngroup GROUP password GROUP_PW username USER password USER_PW priv 3 Before anyone shoots off that there's no nat 0 rule on the remote side, remember that this rule comes automagically from the vpnclient, and is correct - I checked. The any/any access-lists are, of course, just for testing. So they will obviously be changed as soon as the boat is afloat (these firewalls and the VLANs inbetween are actually all on my table at the moment being tested.) I am also aware that I don't need the inside_access_in access-lists - I just use them as an easy way to watch the hit counts for packets being passed. Thanks for any assistance, Chris
-----Original Message----- From: Stejerean, Cosmin [mailto:cosmin@cti.depaul.edu] Sent: Thursday, March 16, 2006 11:35 PM To: Meidinger Chris Subject: RE: PIX dhcprelay via IPSec. Sounds to me that you have a problem with routing. Can you do a traceroute from a client to the DHCP server to make sure that the packet follows the correct route. Why would pinging from the remote pix to the DHCP server work over the inside interface? The inside interface connects you to the client network not the VPN, right? Can you post the entire config file (after sanitizing any confidential information)? Cosmin-----Original Message----- From: Meidinger Chris [mailto:chris.meidinger@badenIT.de] Sent: Thursday, March 16, 2006 1:44 AM To: Stejerean, Cosmin; firewalls@securityfocus.com Subject: RE: PIX dhcprelay via IPSec. Hi Cosmin, I forgot to mention in my original post, that I can hping on udp/67 in both directions as well. I've also noticed, that on the remote firewall i can't ping the DHCP-Server normally, but i can if I specify the inside interface. That is, "ping x.x.x.x" doesn't work, but but "ping inside x.x.x.x" does work. Can anyone think of a reason for that? I'd appreciate any more ideas, because I've got quite a bit of pressure to get this running. Thanks, Chris-----Original Message----- From: Stejerean, Cosmin [mailto:cosmin@cti.depaul.edu] Sent: Thursday, March 16, 2006 3:04 AM To: Meidinger Chris; firewalls@securityfocus.com Subject: RE: PIX dhcprelay via IPSec. Do you have rules to allow traffic on UDP 67 on all the PIXboxes? Thefact that you can ping the DHCP server means you can deliver ICMP packets but UDP packets on port 67 might be filteredalong the way.Try to send a UDP packet on port 67 to the DHCP serverusing nmap andsee if your sniffers pick it up. If it gets dropped youshould seewhere it gets dropped. If this udp packet makes itthrough then youprobably have some more serious issue with the remote pix.Also makesure the return packet can make it's way back to the remote pix. Regards, Cosmin Stejerean-----Original Message----- From: Meidinger Chris [mailto:chris.meidinger@badenIT.de] Sent: Wednesday, March 15, 2006 5:22 PM To: firewalls@securityfocus.com Subject: PIX dhcprelay via IPSec. Hi List, I have a question about relaying DHCP over VPN with PIX. I have the following setup: Client | | | Remote Site PIX running in network-extension mode |V| |P| Internet |N| Central PIX acting as concentrator | | Net 1 | Inside Pix providing access control | | Net 2 | DHCP Server x.x.x.x The client needs to talk to the DHCP-Server in Net 2.It can pingthe DHCP fine so routing and all is OK, but the relayedUnicasts onudp/67 seem to die inside the remote PIX. No logmessages, no debugmessages (at least in any debug mode I though to try) andstill nopacket. I have the following config: hostname(config)# show dhcprelay dhcprelay server x.x.x.x outside dhcprelay enable inside I see statistics, hostname(config)# show dhcprelay stat Packets Relayed BOOTREQUEST 0 DHCPDISCOVER 48 DHCPREQUEST 0 DHCPDECLINE 0 DHCPRELEASE 0 DHCPINFORM 0 BOOTREPLY 0 DHCPOFFER 0 DHCPACK 0 DHCPNAK 0 but no packet in Net 1 and no packet in Net 2 (got inlinesniffersin both trying to troubleshoot this) Can anyone point me in the right direction what the problemmight be?Thanks in advance, Chris
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