I have an OS X 10.4 Server (I know it's old; I just need it to survive a few more months), running a VPN Server. For the past few weeks, all VPN clients have been unable to connect; this is the tail from vpnd.log:
Mon Sep 26 10:57:51 2011 : rcvd [IPCP ConfReq id=0x2 <addr 192.168.1.58> <ms-dns1 192.168.1.1> <ms-dns3 4.2.2.0>]
Mon Sep 26 10:57:51 2011 : sent [IPCP ConfReq id=0xd3 <addr 0.0.0.0>]
Mon Sep 26 10:57:51 2011 : ipcp: returning Configure-ACK
Mon Sep 26 10:57:51 2011 : sent [IPCP ConfAck id=0x2 <addr 192.168.1.58> <ms-dns1 192.168.1.1> <ms-dns3 4.2.2.0>]
Mon Sep 26 10:57:51 2011 : rcvd [IPCP ConfRej id=0xd3 <addr 0.0.0.0>]
Mon Sep 26 10:57:51 2011 : sent [IPCP ConfReq id=0xd4 <addrs 0.0.0.0 192.168.1.58>]
Mon Sep 26 10:57:51 2011 : rcvd [IPCP ConfRej id=0xd4 <addrs 0.0.0.0 192.168.1.58>]
Mon Sep 26 10:57:51 2011 : sent [IPCP ConfReq id=0xd5 <addrs 0.0.0.0 192.168.1.58>]
Mon Sep 26 10:57:51 2011 : rcvd [IPCP ConfRej id=0xd5 <addrs 0.0.0.0 192.168.1.58>]
//Several more of these identical lines omitted.
Mon Sep 26 10:57:52 2011 : sent [IPCP ConfReq id=0xe0 <addrs 0.0.0.0 192.168.1.58>]
Mon Sep 26 10:57:52 2011 : rcvd [IPCP ConfRej id=0xe0 <addrs 0.0.0.0 192.168.1.58>]
Mon Sep 26 10:57:52 2011 : sent [IPCP ConfReq id=0xe1 <addrs 0.0.0.0 192.168.1.58>]
Mon Sep 26 10:57:52 2011 : rcvd [IPCP ConfRej id=0xe1 <addrs 0.0.0.0 192.168.1.58>]
Mon Sep 26 10:57:52 2011 : IPCP: Maximum Config-Requests exceeded
This just repeats as clients try and re-try to get a connection. In the past I've solved this problem by re-booting the server, but that doesn't work now. The exact same thing happens when the client is set to resolve its ip dynamically or statically. This happens with both l2tp and pptp
