From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Gale Subject: Multiple PPTP connections from same public IP ? Date: Tue, 31 Jul 2007 15:36:20 -0600 Message-ID: <46AFAB54.5020602@pason.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: netfilter-bounces@lists.netfilter.org Errors-To: netfilter-bounces@lists.netfilter.org Content-Type: text/plain; charset="us-ascii"; format="flowed" To: netfilter@lists.netfilter.org Hey, I am running Centos 4.4 fully patched and am having a problem PPTP connections. Right now the PPTP server is on the public network and is working correctly for connections from all clients. We have a private network from behind a firewall, let's call it firewall A. A single client from behind firewall A can connect with out a problem, however if a second client tries to connect from behind firewall A it looks like firewall A does not forward the PPP LCP packets. Am I correct that mutliple GRE (proto 47) tunnels would be a problem when the clients have the same IP address ? We are running the standard kernel 2.6.9-42.0.3.EL. Firewall A inside interface: --snip-- 7 1.905608 client server PPTP Outgoing-Call-Request 8 1.910061 server client PPTP Outgoing-Call-Reply 9 1.935465 client server TCP commlinx-avl > pptp [ACK] Seq=325 Ack=189 Win=32120 Len=0 10 2.844911 client server PPTP Set-Link-Info 11 2.909621 client server PPP LCP Configuration Request 12 2.992528 server client TCP pptp > commlinx-avl [ACK] Seq=189 Ack=349 Win=16212 Len=0 13 5.085418 client server PPP LCP Configuration Request 14 7.504568 client server PPP LCP Configuration Request --snip-- Firewall A outside interface: --snip-- 7 1.905608 firewall A server PPTP Outgoing-Call-Request 8 1.910061 server firewall A PPTP Outgoing-Call-Reply 9 1.935465 firewall A server TCP commlinx-avl > pptp [ACK] Seq=325 Ack=189 Win=32120 Len=0 10 2.844911 firewall A server PPTP Set-Link-Info 11 2.992528 server firewall A TCP pptp > commlinx-avl [ACK] Seq=189 Ack=349 Win=16212 Len=0 --snip-- -- Michael Gale Red Hat Certified Engineer Network Administrator Pason Systems Corp.