[vox-tech] SSH On Home Network

[ME]

Jim Angstadt said:
> --- ME <dugan@passwall.com> wrote:
>> Jim Angstadt said:
>> [likely need works with filters]
>> > Could you give me a starting point for this,
>> please.
>>
>> Mike Simmons has asked for the output from two
>> commands in a response to
>> this. This should help you along this path.
>>
>> In addition to his request, could you also pass the
>> contents of the files:
>> /etc/hosts.allow
>
> sshd:  ALL
> [I added this earlier, following directions in a Linux
> Journal tech support article.  No apparent effect.]

This can be an issue if tcpwrappers support was included in your RH8 box.
It still looks like iptable is to blame.

Looking at the output from the iptables, I dont see a rule permitting
packets with a syn flag set to port 22 for ssh.

(Background: this is take from examination of the "flags" section, and
having an understanding of a tcp packet and the flags
http://mike.passwall.com/networking/tcppacket.html )

Pulling from other mail:
----
    0     0 ACCEPT     tcp  --  *      *
 0.0.0.0/0            0.0.0.0/0          tcp dpt:22
 flags:0x16/0x02
----

Could you try this:
# iptables -t filter -D  INPUT 1 -p tcp -s 192.168.0.0/24 -d 192.168.0.3\
 --destination-port 22 -j ACCEPT

(If the line sould wrap, the "\" at the end of the first should permit you
to paste it into a shell and then just press return.)

Then try to ssh to the box from one of the others. (This is just a test,
not a permanant fix. It inserts a rule at the top of the list to allow all
IP from your private net 192.168.0.[0-255] to connect with tcp to that
machine's port 22.)

If you can ssh to the box. Then we can proceed from here and try to make
the "fix" a permanent one.

If you cannot, then it would be a good idea to remove that rule we just
inserted:
# iptables -t filter -D INPUT 1

When you ssh from the other box to this one, please give it some time to
connect. Often ssh is configured to perform rDNS for each incoming
connection. When this is the case, and your ssh server is behind a private
network, it may take some time for the rDNS to fail before the ssh is
permitted to pass through.


>> /etc/hosts.deny
>
> empty.

OK.

-ME




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