我在Debian上使用KVM。 我想用命令ssh 1.2.3.4 -p 10122使用ssh连接到guest ssh 1.2.3.4 -p 10122 。 我所做的是：
root@host$ iptables -t nat -A PREROUTING -p TCP --dport 10122 -j DNAT --to-destination 192.168.122.208:22
iptables-save的结果：
# Generated by iptables-save v1.4.14 on Sat Nov 16 01:03:28 2013 *nat :PREROUTING ACCEPT [64:9345] :INPUT ACCEPT [64:9345] :OUTPUT ACCEPT [112:7287] :POSTROUTING ACCEPT [112:7287] -A PREROUTING -p tcp -m tcp --dport 10122 -j DNAT --to-destination 192.168.122.208:22 -A POSTROUTING -s 192.168.122.0/24 ! -d 192.168.122.0/24 -p tcp -j MASQUERADE --to-ports 1024-65535 -A POSTROUTING -s 192.168.122.0/24 ! -d 192.168.122.0/24 -p udp -j MASQUERADE --to-ports 1024-65535 -A POSTROUTING -s 192.168.122.0/24 ! -d 192.168.122.0/24 -j MASQUERADE COMMIT # Completed on Sat Nov 16 01:03:28 2013 # Generated by iptables-save v1.4.14 on Sat Nov 16 01:03:28 2013 *mangle :PREROUTING ACCEPT [16331:11525510] :INPUT ACCEPT [16327:11525270] :FORWARD ACCEPT [4:240] :OUTPUT ACCEPT [15827:1491721] :POSTROUTING ACCEPT [15827:1491721] -A POSTROUTING -o virbr0 -p udp -m udp --dport 68 -j CHECKSUM --checksum-fill COMMIT # Completed on Sat Nov 16 01:03:28 2013 # Generated by iptables-save v1.4.14 on Sat Nov 16 01:03:28 2013 *filter :INPUT ACCEPT [7865:6008003] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [7723:676522] -A INPUT -i virbr0 -p udp -m udp --dport 53 -j ACCEPT -A INPUT -i virbr0 -p tcp -m tcp --dport 53 -j ACCEPT -A INPUT -i virbr0 -p udp -m udp --dport 67 -j ACCEPT -A INPUT -i virbr0 -p tcp -m tcp --dport 67 -j ACCEPT -A FORWARD -d 192.168.122.0/24 -o virbr0 -m state --state RELATED,ESTABLISHED -j ACCEPT -A FORWARD -s 192.168.122.0/24 -i virbr0 -j ACCEPT -A FORWARD -i virbr0 -o virbr0 -j ACCEPT -A FORWARD -o virbr0 -j REJECT --reject-with icmp-port-unreachable -A FORWARD -i virbr0 -j REJECT --reject-with icmp-port-unreachable -A FORWARD -d 192.168.122.208/32 -p tcp -m tcp --dport 22 -j ACCEPT COMMIT # Completed on Sat Nov 16 01:03:28 2013
但它不起作用：
me@dauphine:~ $ ssh [email protected] -v OpenSSH_6.2p2 Ubuntu-6ubuntu0.1, OpenSSL 1.0.1e 11 Feb 2013 debug1: Reading configuration data /home/me/.ssh/config debug1: /home/me/.ssh/config line 1: Applying options for * debug1: /home/me/.ssh/config line 61: Applying options for flora.vm01 debug1: Reading configuration data /etc/ssh/ssh_config debug1: /etc/ssh/ssh_config line 19: Applying options for * debug1: Connecting to flora.me.net [1.2.3.4] port 10122. debug1: connect to address 1.2.3.4 port 10122: Connection refused ssh: connect to host flora.me.net port 10122: Connection refused
在这里find答案https://serverfault.com/a/170641/88934 。 还有一条规则：
iptables -I FORWARD -m state -d 10.0.0.0/24 --state NEW,RELATED,ESTABLISHED -j ACCEPT
默认的KVM NATconfiguration提供了一个类似于此的规则，但省略了NEW状态，这对于接受传入连接是必不可less的。