I have a Box 'foo' which has sshd running. I wish to ssh to this machine via Box 'bar'. Box 'foo' has the IP address 10.0.0.100 and Box 'bar' has the IP 10.0.0.109. The gateway for both of these machines is 10.0.0.10. If I am outside the LAN, I can ssh to Box 'foo' just fine.
I fear it has something to do with my iptables running on the gateway. Can someone double check my work for me? I can't figure it out.
Seems as there's no route between machines on the LAN. Should mention that Box 'foo' is connected to gateway via eth1 (gateway) and Box 'bar' is connected via wlan0 (gateway). Both these interfaces are bridged as 'br0'.
I have a firewall on box 'foo' however, it was disabled for testing.
I figured out that by changing the policy from Drop to Forward on iptables on gateway, connecting are allowed once again. Now my question is how can I insert a rule that allows LAN connections to occur while keeping Forward's polic on Drop?
$ cat /etc/ssh/sshd_config ## ON BOX 'foo' # Package generated configuration file # See the sshd_config(5) manpage for details # What ports, IPs and protocols we listen for Port 22 # Use these options to restrict which interfaces/protocols sshd will bind to #ListenAddress :: #ListenAddress 0.0.0.0 Protocol 2 # HostKeys for protocol version 2 HostKey /etc/ssh/ssh_host_rsa_key HostKey /etc/ssh/ssh_host_dsa_key HostKey /etc/ssh/ssh_host_ecdsa_key HostKey /etc/ssh/ssh_host_ed25519_key #Privilege Separation is turned on for security UsePrivilegeSeparation yes # Lifetime and size of ephemeral version 1 server key KeyRegenerationInterval 3600 ServerKeyBits 1024 # Logging SyslogFacility AUTH LogLevel VERBOSE # Authentication: LoginGraceTime 120 PermitRootLogin no StrictModes yes RSAAuthentication yes PubkeyAuthentication yes #AuthorizedKeysFile %h/.ssh/authorized_keys # Don't read the user's ~/.rhosts and ~/.shosts files IgnoreRhosts yes # For this to work you will also need host keys in /etc/ssh_known_hosts RhostsRSAAuthentication no # similar for protocol version 2 HostbasedAuthentication no # Uncomment if you don't trust ~/.ssh/known_hosts for RhostsRSAAuthentication #IgnoreUserKnownHosts yes # To enable empty passwords, change to yes (NOT RECOMMENDED) PermitEmptyPasswords no # Change to yes to enable challenge-response passwords (beware issues with # some PAM modules and threads) ChallengeResponseAuthentication no # Change to no to disable tunnelled clear text passwords PasswordAuthentication no # Kerberos options #KerberosAuthentication no #KerberosGetAFSToken no #KerberosOrLocalPasswd yes #KerberosTicketCleanup yes # GSSAPI options #GSSAPIAuthentication no #GSSAPICleanupCredentials yes X11Forwarding yes X11DisplayOffset 10 PrintMotd no PrintLastLog yes TCPKeepAlive yes #UseLogin no #MaxStartups 10:30:60 Banner /etc/issue.net # Allow client to pass locale environment variables AcceptEnv LANG LC_* # Subsystem sftp /usr/lib/openssh/sftp-server #out 2/20/16 # 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 # Allow limited users access to server AllowUsers foouser XXXXXXXXXX # <--- Censored # SFTP Subsystem Subsystem sftp internal-sftp Match group XXXXXXXXXX # <--- Censored ChrootDirectory /srv/sftp X11Forwarding no AllowTcpForwarding no ForceCommand internal-sftp
# iptables -nvL ## ON gateway Chain INPUT (policy DROP 0 packets, 0 bytes) pkts bytes target prot opt in out source destination 0 0 ACCEPT all -- lo * 0.0.0.0/0 0.0.0.0/0 703 52346 ACCEPT all -- * * 0.0.0.0/0 0.0.0.0/0 ctstate RELATED,ESTABLISHED 0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:22 0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:2022 7 757 LOGNDROP all -- * * 0.0.0.0/0 0.0.0.0/0 Chain FORWARD (policy DROP 0 packets, 0 bytes) pkts bytes target prot opt in out source destination 110 21617 ACCEPT all -- eth0 br0 0.0.0.0/0 0.0.0.0/0 ctstate RELATED,ESTABLISHED 126 16289 ACCEPT all -- br0 eth0 0.0.0.0/0 0.0.0.0/0 0 0 ACCEPT tcp -- * * 0.0.0.0/0 10.0.0.100 tcp dpt:22 state NEW,RELATED,ESTABLISHED Chain OUTPUT (policy ACCEPT 0 packets, 0 bytes) pkts bytes target prot opt in out source destination 0 0 ACCEPT all -- * lo 0.0.0.0/0 0.0.0.0/0 590 173K ACCEPT all -- * * 0.0.0.0/0 0.0.0.0/0 ctstate RELATED,ESTABLISHED Chain LOGNDROP (1 references) pkts bytes target prot opt in out source destination 7 757 LOG all -- * * 0.0.0.0/0 0.0.0.0/0 LOG flags 0 level 4 prefix "iptables: " 7 757 DROP all -- * * 0.0.0.0/0 0.0.0.0/0