OpenVPN은 서버에 대한 SMTP 액세스를 완전히 차단합니다.

OpenVPN은 서버에 대한 SMTP 액세스를 완전히 차단합니다.

openvpn 서버에서 smtp를 차단하기 위해 거의 모든 iptables 규칙을 시도했지만 클라이언트는 여전히 포트 25에서 원격 smtp 서버에 액세스할 수 있습니다.

openvpn을 사용하여 서버에 액세스하고 있습니다. 두 개의 인터페이스 as0t0 및 as0t1을 생성합니다.

모든 사용자 할당 IP는 172.16.0.0/12입니다.

이 문제를 해결하기 위해 어떤 규칙을 작성해야 하는지 도와주세요.

openvpn 액세스 서버에 의해 설정된 iptables 규칙:

#Generated by iptables-save v1.4.7 on Sun Apr 10 13:03:56 2016
*nat
:PREROUTING ACCEPT [566:72410]
:POSTROUTING ACCEPT [36:2340]
:OUTPUT ACCEPT [36:2340]
:AS0_NAT - [0:0]
:AS0_NAT_POST_REL_EST - [0:0]
:AS0_NAT_PRE - [0:0]
:AS0_NAT_PRE_REL_EST - [0:0]
:AS0_NAT_TEST - [0:0]
-A PREROUTING -m state --state RELATED,ESTABLISHED -j AS0_NAT_PRE_REL_EST 
-A POSTROUTING -m state --state RELATED,ESTABLISHED -j AS0_NAT_POST_REL_EST 
-A POSTROUTING -m mark --mark 0x2000000/0x2000000 -j AS0_NAT_PRE 
-A AS0_NAT -o eth0 -j SNAT --to-source 91.13.18.170 
-A AS0_NAT -j ACCEPT 
-A AS0_NAT_POST_REL_EST -j ACCEPT 
-A AS0_NAT_PRE -m mark --mark 0x8000000/0x8000000 -j AS0_NAT 
-A AS0_NAT_PRE -d 192.168.0.0/16 -j AS0_NAT_TEST 
-A AS0_NAT_PRE -d 172.16.0.0/12 -j AS0_NAT_TEST 
-A AS0_NAT_PRE -d 10.0.0.0/8 -j AS0_NAT_TEST 
-A AS0_NAT_PRE -j AS0_NAT 
-A AS0_NAT_PRE_REL_EST -j ACCEPT 
-A AS0_NAT_TEST -o as0t+ -j ACCEPT 
-A AS0_NAT_TEST -m mark --mark 0x4000000/0x4000000 -j ACCEPT 
-A AS0_NAT_TEST -d 172.27.224.0/20 -j ACCEPT 
-A AS0_NAT_TEST -j AS0_NAT 
COMMIT
# Completed on Sun Apr 10 13:03:56 2016
# Generated by iptables-save v1.4.7 on Sun Apr 10 13:03:56 2016
*mangle
:PREROUTING ACCEPT [146:10130]
:INPUT ACCEPT [6422:1226373]
:FORWARD ACCEPT [8289:2947415]
:OUTPUT ACCEPT [5446:2764996]
:POSTROUTING ACCEPT [13735:5712411]
:AS0_MANGLE_PRE_REL_EST - [0:0]
:AS0_MANGLE_TUN - [0:0]
-A PREROUTING -m state --state RELATED,ESTABLISHED -j AS0_MANGLE_PRE_REL_EST 
-A PREROUTING -i as0t+ -j AS0_MANGLE_TUN 
-A AS0_MANGLE_PRE_REL_EST -j ACCEPT 
-A AS0_MANGLE_TUN -j MARK --set-xmark 0x2000000/0xffffffff 
-A AS0_MANGLE_TUN -j ACCEPT 
COMMIT
# Completed on Sun Apr 10 13:03:56 2016
# Generated by iptables-save v1.4.7 on Sun Apr 10 13:03:56 2016
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [3970:2307554]
:AS0_ACCEPT - [0:0]
:AS0_IN - [0:0]
:AS0_IN_NAT - [0:0]
:AS0_IN_POST - [0:0]
:AS0_IN_PRE - [0:0]
:AS0_IN_ROUTE - [0:0]
:AS0_OUT - [0:0]
:AS0_OUT_LOCAL - [0:0]
:AS0_OUT_POST - [0:0]
:AS0_OUT_S2C - [0:0]
:AS0_WEBACCEPT - [0:0]
-A INPUT -m state --state RELATED,ESTABLISHED -j AS0_ACCEPT 
-A INPUT -i lo -j AS0_ACCEPT 
-A INPUT -m mark --mark 0x2000000/0x2000000 -j AS0_IN_PRE 
-A INPUT -d 91.13.18.170/32 -p udp -m state --state NEW -m udp --dport 1194 -j AS0_ACCEPT 
-A INPUT -d 91.13.18.170/32 -p tcp -m state --state NEW -m tcp --dport 443 -j AS0_ACCEPT 
-A INPUT -m state --state RELATED,ESTABLISHED -j AS0_WEBACCEPT 
-A INPUT -d 91.13.18.170/32 -p tcp -m state --state NEW -m tcp --dport 943 -j AS0_WEBACCEPT 
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT 
-A INPUT -p icmp -j ACCEPT 
-A INPUT -i lo -j ACCEPT 
-A INPUT -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 25 -j DROP 
-A INPUT -p udp -m udp --dport 25 -j DROP 
-A INPUT -j REJECT --reject-with icmp-host-prohibited 
-A INPUT -i eth0 -p tcp -m tcp --dport 25 -j DROP 
-A INPUT -i as0t0 -p tcp -m tcp --dport 25 -j DROP 
-A INPUT -i as0t1 -p tcp -m tcp --dport 25 -j DROP 
-A INPUT -p tcp -m tcp --dport 25 -j REJECT --reject-with icmp-port-unreachable 
-A FORWARD -m state --state RELATED,ESTABLISHED -j AS0_ACCEPT 
-A FORWARD -m mark --mark 0x2000000/0x2000000 -j AS0_IN_PRE 
-A FORWARD -o as0t+ -j AS0_OUT_S2C 
-A FORWARD -j REJECT --reject-with icmp-host-prohibited 
-A FORWARD -i eth0 -p tcp -m tcp --dport 25 -j DROP 
-A FORWARD -i as0t0 -p tcp -m tcp --dport 25 -j DROP 
-A FORWARD -i as0t1 -p tcp -m tcp --dport 25 -j DROP 
-A FORWARD -i lo -p tcp -m tcp --dport 25 -j DROP 
-A FORWARD -i as0t+ -p tcp -m tcp --dport 25 -j DROP 
-A FORWARD -i as0t0 -p tcp -m tcp --dport 25 -j DROP 
-A FORWARD -i as0t1 -p tcp -m tcp --dport 25 -j DROP 
-A OUTPUT -o as0t+ -j AS0_OUT_LOCAL 
-A OUTPUT -p tcp -m tcp --dport 25 -j DROP 
-A OUTPUT -p tcp -m tcp --dport 25 -j DROP 
-A AS0_ACCEPT -j ACCEPT 
-A AS0_IN -d 172.27.224.1/32 -j ACCEPT 
-A AS0_IN -j AS0_IN_POST 
-A AS0_IN_NAT -j MARK --set-xmark 0x8000000/0x8000000 
-A AS0_IN_NAT -j ACCEPT 
-A AS0_IN_POST -o as0t+ -j AS0_OUT 
-A AS0_IN_POST -j DROP 
-A AS0_IN_PRE -d 192.168.0.0/16 -j AS0_IN 
-A AS0_IN_PRE -d 172.16.0.0/12 -j AS0_IN 
-A AS0_IN_PRE -d 10.0.0.0/8 -j AS0_IN 
-A AS0_IN_PRE -j ACCEPT 
-A AS0_IN_ROUTE -j MARK --set-xmark 0x4000000/0x4000000 
-A AS0_IN_ROUTE -j ACCEPT 
-A AS0_OUT -j AS0_OUT_POST 
-A AS0_OUT_LOCAL -p icmp -m icmp --icmp-type 5 -j DROP 
-A AS0_OUT_LOCAL -j ACCEPT 
-A AS0_OUT_POST -j DROP 
-A AS0_OUT_S2C -j AS0_OUT 
-A AS0_WEBACCEPT -j ACCEPT 
COMMIT
# Completed on Sun Apr 10 13:03:56 2016

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