PPTPD клиенты не видят друг друга.

localip 10.0.0.1
remoteip 10.0.0.100-102
auth
proxyarp
option /etc/ppp/options.pptpd

-A INPUT -s 37.190.111.1 -p tcp -m tcp --dport 1723 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 22 -j fail2ban-SSH 
-A INPUT -p tcp -m tcp --dport 21 -j fail2ban-pureftpd 
-A INPUT -m state --state INVALID -j DROP 
-A INPUT -i lo -j ACCEPT 
-A INPUT -d 127.0.0.0/8 -j REJECT --reject-with icmp-port-unreachable 

-A INPUT -p icmp -j ACCEPT 
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 20 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 21 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 22 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 2222 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 25 --tcp-flags FIN,SYN,RST,ACK SYN -m limit --limit 1/sec --limit-burst 10 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 25 --tcp-flags FIN,SYN,RST,ACK SYN -j DROP 
-A INPUT -p tcp -m tcp --dport 25 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 465 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 587 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 53 -j ACCEPT 
-A INPUT -p udp -m udp --dport 53 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 80 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 110 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 995 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 113 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 143 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 993 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 443 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 3306 -j ACCEPT 
-A INPUT -p udp -m udp --dport 3306 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 1433 -m limit --limit 3/hour -j LOG --log-prefix "Firewalled packet: MSSQL " 
-A INPUT -p tcp -m tcp --dport 1433 -j DROP 
-A INPUT -p tcp -m tcp --dport 6670 -m limit --limit 3/hour -j LOG --log-prefix "Firewalled packet: Deepthrt " 
-A INPUT -p tcp -m tcp --dport 6670 -j DROP 
-A INPUT -p tcp -m tcp --dport 6711 -m limit --limit 3/hour -j LOG --log-prefix "Firewalled packet: Sub7 " 
-A INPUT -p tcp -m tcp --dport 6711 -j DROP 
-A INPUT -p tcp -m tcp --dport 6712 -m limit --limit 3/hour -j LOG --log-prefix "Firewalled packet: Sub7 " 
-A INPUT -p tcp -m tcp --dport 6712 -j DROP 
-A INPUT -p tcp -m tcp --dport 6713 -m limit --limit 3/hour -j LOG --log-prefix "Firewalled packet: Sub7 " 
-A INPUT -p tcp -m tcp --dport 6713 -j DROP 
-A INPUT -p tcp -m tcp --dport 12345 -m limit --limit 3/hour -j LOG --log-prefix "Firewalled packet: Netbus " 
-A INPUT -p tcp -m tcp --dport 12345 -j DROP 
-A INPUT -p tcp -m tcp --dport 12346 -m limit --limit 3/hour -j LOG --log-prefix "Firewalled packet: Netbus " 
-A INPUT -p tcp -m tcp --dport 12346 -j DROP 
-A INPUT -p tcp -m tcp --dport 20034 -m limit --limit 3/hour -j LOG --log-prefix "Firewalled packet: Netbus " 
-A INPUT -p tcp -m tcp --dport 20034 -j DROP 
-A INPUT -p tcp -m tcp --dport 31337 -m limit --limit 3/hour -j LOG --log-prefix "Firewalled packet: BO " 
-A INPUT -p tcp -m tcp --dport 31337 -j DROP 
-A INPUT -p tcp -m tcp --dport 6000 -m limit --limit 3/hour -j LOG --log-prefix "Firewalled packet: XWin " 
-A INPUT -p tcp -m tcp --dport 6000 -j DROP 
-A INPUT -p udp -m udp --dport 33434:33523 -j DROP 
-A INPUT -p tcp -m tcp --dport 113 -j REJECT --reject-with icmp-port-unreachable 
-A INPUT -p igmp -j REJECT --reject-with icmp-port-unreachable 
-A INPUT -p tcp -m tcp --dport 80 -j REJECT --reject-with icmp-port-unreachable 
-A INPUT -p tcp -m tcp --dport 443 -j REJECT --reject-with icmp-port-unreachable 
-A INPUT -p tcp -m tcp --tcp-flags FIN,SYN,RST,ACK SYN -m limit --limit 5/min -j LOG --log-prefix "Firewalled packet:" 
-A INPUT -p tcp -j REJECT --reject-with tcp-reset 
-A INPUT -j DROP 
-A INPUT -s 89.35.160.61/32 -j REJECT --reject-with icmp-port-unreachable 
-A INPUT -s 188.143.232.37/32 -j REJECT --reject-with icmp-port-unreachable 
-A INPUT -p tcp -m tcp --dport 4949 -j ACCEPT 
-A INPUT -s 192.168.1.0/24 -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 3129 -j DROP 
-A FORWARD -m state --state INVALID -j DROP 
-A FORWARD -p tcp -m tcp --tcp-flags FIN,SYN,RST,ACK SYN -m limit --limit 5/min -j LOG --log-prefix "Firewalled packet:" 
-A FORWARD -p tcp -j REJECT --reject-with tcp-reset 
-A FORWARD -i ppp+ -o eth0 -j ACCEPT 
-A FORWARD -i eth0 -o ppp+ -j ACCEPT 
-A OUTPUT -p tcp -m tcp --dport 3128 -j ACCEPT 
-A OUTPUT -p tcp -m tcp --dport 6660:6669 -j DROP 
-A OUTPUT -p tcp -m tcp --dport 7000 -j DROP 
-A OUTPUT -p tcp -m owner --uid-owner mail -m tcp --dport 25 -j ACCEPT 
-A OUTPUT -p tcp -m owner --uid-owner root -m tcp --dport 25 -j ACCEPT 
-A OUTPUT -d 127.0.0.1/32 -p tcp -m tcp --dport 25 -j ACCEPT 
-A OUTPUT -p tcp -m tcp --dport 25 -j REJECT --reject-with icmp-port-unreachable 
-A OUTPUT -j ACCEPT 
COMMIT

pptp-pptp_clien Link encap:Point-to-Point Protocol
          inet addr:10.0.0.101  P-t-P:10.0.0.1  Mask:255.255.255.255
          UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1500  Metric:1
          RX packets:1218 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1252 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:64
          RX bytes:8904 (8.6 KiB)  TX bytes:11474 (11.2 KiB)