Im having issues getting iptables to allow an inbound connection for ssh. I have port forwarding enabled on my router, and can access the machine via ssh when iptables is stopped.
The rule I used to allow the connection is:
I have sshd setup to use port 26 rather than port 22. Even in a local network setting, I cannot get a connection.Code:iptables -A open -p tcp --dport 26 -j ACCEPT
My /etc/ssh/ssh_config is as follows:
And my /etc/ssh/sshd_config:Code:# $OpenBSD: ssh_config,v 1.25 2009/02/17 01:28:32 djm Exp $ # This is the ssh client system-wide configuration file. See # ssh_config(5) for more information. This file provides defaults for # users, and the values can be changed in per-user configuration files # or on the command line. # Configuration data is parsed as follows: # 1. command line options # 2. user-specific file # 3. system-wide file # Any configuration value is only changed the first time it is set. # Thus, host-specific definitions should be at the beginning of the # configuration file, and defaults at the end. # Site-wide defaults for some commonly used options. For a comprehensive # list of available options, their meanings and defaults, please see the # ssh_config(5) man page. Host * # ForwardAgent no # ForwardX11 no # RhostsRSAAuthentication no # RSAAuthentication yes # PasswordAuthentication yes # HostbasedAuthentication no # GSSAPIAuthentication no # GSSAPIDelegateCredentials no # BatchMode no # CheckHostIP yes # AddressFamily any # ConnectTimeout 0 # StrictHostKeyChecking ask # IdentityFile ~/.ssh/identity # IdentityFile ~/.ssh/id_rsa # IdentityFile ~/.ssh/id_dsa Port 26 Protocol 2 # Cipher 3des # Ciphers aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc # MACs hmac-md5,hmac-sha1,umac-64@openssh.com,hmac-ripemd160 # EscapeChar ~ # Tunnel no # TunnelDevice any:any # PermitLocalCommand no # VisualHostKey no HashKnownHosts yes StrictHostKeyChecking ask
And finally the printout from iptables -nvL. When I setup iptables I didnt realize I could setup rules for all interfaces, so I set the rules for each interface individually:Code:# $OpenBSD: sshd_config,v 1.80 2008/07/02 02:24:18 djm Exp $ # This is the sshd server system-wide configuration file. See # sshd_config(5) for more information. # This sshd was compiled with PATH=/usr/bin:/bin:/usr/sbin:/sbin # The strategy used for options in the default sshd_config shipped with # OpenSSH is to specify options with their default value where # possible, but leave them commented. Uncommented options change a # default value. Port 26 #AddressFamily any ListenAddress 0.0.0.0 #ListenAddress :: # Disable legacy (protocol version 1) support in the server for new # installations. In future the default will change to require explicit # activation of protocol 1 Protocol 2 # HostKey for protocol version 1 #HostKey /etc/ssh/ssh_host_key # HostKeys for protocol version 2 #HostKey /etc/ssh/ssh_host_rsa_key #HostKey /etc/ssh/ssh_host_dsa_key # Lifetime and size of ephemeral version 1 server key #KeyRegenerationInterval 1h #ServerKeyBits 1024 # Logging # obsoletes QuietMode and FascistLogging #SyslogFacility AUTH #LogLevel INFO # Authentication: #LoginGraceTime 120 #PermitRootLogin no #StrictModes yes #MaxAuthTries 6 #MaxSessions 10 #RSAAuthentication yes #PubkeyAuthentication yes #AuthorizedKeysFile .ssh/authorized_keys # For this to work you will also need host keys in /etc/ssh/ssh_known_hosts #RhostsRSAAuthentication no # similar for protocol version 2 #HostbasedAuthentication no # Change to yes if you don't trust ~/.ssh/known_hosts for # RhostsRSAAuthentication and HostbasedAuthentication #IgnoreUserKnownHosts no # Don't read the user's ~/.rhosts and ~/.shosts files #IgnoreRhosts yes # To disable tunneled clear text passwords, change to no here! PasswordAuthentication yes #PermitEmptyPasswords no # Change to no to disable s/key passwords ChallengeResponseAuthentication no # Kerberos options #KerberosAuthentication no #KerberosOrLocalPasswd yes #KerberosTicketCleanup yes #KerberosGetAFSToken no # GSSAPI options #GSSAPIAuthentication no #GSSAPICleanupCredentials yes # Set this to 'yes' to enable PAM authentication, account processing, # and session processing. If this is enabled, PAM authentication will # be allowed through the ChallengeResponseAuthentication and # PasswordAuthentication. Depending on your PAM configuration, # PAM authentication via ChallengeResponseAuthentication may bypass # the setting of "PermitRootLogin without-password". # If you just want the PAM account and session checks to run without # PAM authentication, then enable this but set PasswordAuthentication # and ChallengeResponseAuthentication to 'no'. UsePAM yes #AllowAgentForwarding yes #AllowTcpForwarding yes #GatewayPorts no #X11Forwarding no #X11DisplayOffset 10 #X11UseLocalhost yes #PrintMotd yes #PrintLastLog yes #TCPKeepAlive yes #UseLogin no #UsePrivilegeSeparation yes #PermitUserEnvironment no #Compression delayed #ClientAliveInterval 0 #ClientAliveCountMax 3 #UseDNS yes #PidFile /var/run/sshd.pid #MaxStartups 10 #PermitTunnel no #ChrootDirectory none # no default banner path Banner /etc/issue # override default of no subsystems Subsystem sftp /usr/lib/ssh/sftp-server # Example of overriding settings on a per-user basis #Match User anoncvs # X11Forwarding no # AllowTcpForwarding no # ForceCommand cvs server AllowUsers username (I actually have my username here)
Any ideas, or criticisms of my setup are welcomeCode:Chain INPUT (policy DROP 0 packets, 0 bytes) pkts bytes target prot opt in out source destination 0 0 DROP icmp -- * * 0.0.0.0/0 0.0.0.0/0 icmp type 18 0 0 DROP icmp -- * * 0.0.0.0/0 0.0.0.0/0 icmp type 17 0 0 DROP icmp -- * * 0.0.0.0/0 0.0.0.0/0 icmp type 10 0 0 DROP icmp -- * * 0.0.0.0/0 0.0.0.0/0 icmp type 9 0 0 DROP icmp -- * * 0.0.0.0/0 0.0.0.0/0 icmp type 9 0 0 DROP icmp -- * * 0.0.0.0/0 0.0.0.0/0 icmp type 5 0 0 DROP all -- wlan0 * 127.0.0.0/8 0.0.0.0/0 0 0 DROP all -- eth1 * 127.0.0.0/8 0.0.0.0/0 0 0 DROP all -- eth0 * 127.0.0.0/8 0.0.0.0/0 0 0 DROP all -- wlan0 * 192.168.0.0/16 0.0.0.0/0 0 0 DROP all -- eth1 * 192.168.0.0/16 0.0.0.0/0 0 0 DROP all -- eth0 * 192.168.0.0/16 0.0.0.0/0 0 0 DROP all -- eth1 * 172.16.0.0/12 0.0.0.0/0 0 0 DROP all -- wlan0 * 172.16.0.0/12 0.0.0.0/0 0 0 DROP all -- eth0 * 172.16.0.0/12 0.0.0.0/0 0 0 DROP all -- wlan0 * 10.0.0.0/8 0.0.0.0/0 0 0 DROP all -- eth1 * 10.0.0.0/8 0.0.0.0/0 0 0 DROP all -- eth0 * 10.0.0.0/8 0.0.0.0/0 0 0 ACCEPT icmp -- * * 0.0.0.0/0 0.0.0.0/0 71 58876 ACCEPT all -- * * 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED 0 0 interfaces all -- * * 0.0.0.0/0 0.0.0.0/0 0 0 open all -- * * 0.0.0.0/0 0.0.0.0/0 0 0 REJECT tcp -- * * 0.0.0.0/0 0.0.0.0/0 reject-with tcp-reset 0 0 REJECT udp -- * * 0.0.0.0/0 0.0.0.0/0 reject-with icmp-port-unreachable 0 0 DROP tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp flags:!0x17/0x02 state NEW 0 0 DROP all -f * * 0.0.0.0/0 0.0.0.0/0 0 0 DROP tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp flags:0x3F/0x3F 0 0 DROP tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp flags:0x3F/0x00 0 0 DROP icmp -- eth0 * 0.0.0.0/0 0.0.0.0/0 icmp type 8 0 0 DROP icmp -- eth1 * 0.0.0.0/0 0.0.0.0/0 icmp type 8 0 0 DROP icmp -- wlan0 * 0.0.0.0/0 0.0.0.0/0 icmp type 8 0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:26 Chain FORWARD (policy DROP 0 packets, 0 bytes) pkts bytes target prot opt in out source destination Chain OUTPUT (policy ACCEPT 30 packets, 1236 bytes) pkts bytes target prot opt in out source destination Chain interfaces (1 references) pkts bytes target prot opt in out source destination 0 0 ACCEPT all -- lo * 0.0.0.0/0 0.0.0.0/0 Chain open (1 references) pkts bytes target prot opt in out source destination 0 0 ACCEPT tcp -- ppp0 * 0.0.0.0/0 0.0.0.0/0 tcp dpt:80 0 0 ACCEPT tcp -- wlan0 * 0.0.0.0/0 0.0.0.0/0 tcp dpt:80 0 0 ACCEPT tcp -- eth0 * 0.0.0.0/0 0.0.0.0/0 tcp dpt:80 0 0 ACCEPT tcp -- eth1 * 0.0.0.0/0 0.0.0.0/0 tcp dpt:80 0 0 ACCEPT tcp -- foo * 0.0.0.0/0 0.0.0.0/0 tcp dpts:65000:65005 0 0 ACCEPT tcp -- wlan0 * 0.0.0.0/0 0.0.0.0/0 tcp dpts:65000:65005 0 0 ACCEPT tcp -- eth0 * 0.0.0.0/0 0.0.0.0/0 tcp dpts:65000:65005 0 0 ACCEPT tcp -- eth1 * 0.0.0.0/0 0.0.0.0/0 tcp dpts:65000:65005 0 0 ACCEPT udp -- foo * 0.0.0.0/0 0.0.0.0/0 udp dpts:65000:65005 0 0 ACCEPT udp -- wlan0 * 0.0.0.0/0 0.0.0.0/0 udp dpts:65000:65005 0 0 ACCEPT udp -- eth0 * 0.0.0.0/0 0.0.0.0/0 udp dpts:65000:65005 0 0 ACCEPT udp -- eth1 * 0.0.0.0/0 0.0.0.0/0 udp dpts:65000:65005 0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:26
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