vcnviewer not connecting

kenneth_phough · 01-11-2013, 08:04 AM

I'm having a hard time understanding the shorewall config at the moment so I'm going to go back to the iptables config you posted which I assume shorewall generated and will edit this post on any findings.

EDIT

Okay, I think I understand the shorewall situation a bit more. It's hard to say perfectly without looking at a few shorewall config files. From what I can tell you need to explicitly tell shorewall to trust your virtual interface (ham0). So reading up a bit on their documentation the first thing you should do is create a zone for your hamachi connection, let call it ham, in your

Code:

# /etc/shorewall/zones

ham             ipv4

Then add your interface to

Code:

# /etc/shorewall/interfaces

ham             ham0             -

and lastly allow traffic on the newly created zone

Code:

# /etc/shorewall/policy OR /etc/shorewall/rules

ham             <ZONE FOR YOUR LOCAL ETH>             ACCEPT
<ZONE FOR YOUR LOCAL ETH>             ham             ACCEPT

Then restart shorewall.

The above example, will allow all traffic in and out on the VPN network so you may want to adjust the policy accordingly. I've never used shorewall but reading the docs this should work???

Remeber to back up all config files before modifying them so you have something to fall back to

Ps. Like I've said I've never used shorewall before and I'm basing my suggestion from what I've read online so correct me if I am completely wrong regarding shorewall configs!

Johng · 01-11-2013, 02:14 PM

Thank you Ken for the time you are spending on my behalf, it's much appreciated.

Before making changes, I thought it my be useful to show the "before" content of the relevant files:

zones
net ipv4
loc ipv4
fw firewall

interfaces
net eth0 detect
loc ham0 detect
loc ham1 detect

policy
loc net ACCEPT
loc fw ACCEPT
fw loc ACCEPT
fw net ACCEPT
net all DROP
all all REJECT info

rules
INCLUDE rules.drakx

rules.drakx
ACCEPT net fw udp 53,5353,427,60:2000,8080 -
ACCEPT net fw tcp 80,443,53,22,20,21,1900,59631 -

I'm not sure what is meant by "<ZONE FOR YOUR LOCAL ETH>"

Johng · 01-12-2013, 09:52 PM

Well, I've had a degree of success.

I have found that if I start hamachi, login, and set mode to ipv4, AND then restart shorewall, vncviewer connects to the remote desktop. In other words shorewall needs to 'refresh' after ham0 has been created by hamachi. This will explain why I had momentary unexplained connections descibed earlier (after I had meddled with the firewall). Vncviewer uses port 5900.

I tried # /etc/shorewall/interfaces
ham ham0 -

but this came up invalid, when I ran shorewall check.

When I restart shorewall, I get 14 x "iptables: Input/output error" corresponding with the number of ports in rules.

I'm not sure how to avoid the need to restart shorewall after ham0 has been created.

kenneth_phough · 01-15-2013, 12:48 PM

Update: Ok, in the shorewall documentation (http://www.shorewall.net/manpages/sh...nterfaces.html) it mentioned that detecting broadcast is deprecated and should only be used if your iptables is supported. with that said I found a few articles explaining how to configure shorewall and hamachi and it seems like they leave the broadcast detect empty.

/etc/shorewall/zones

Code:

# I'm going to use ham as a zone name just because loc kinda confused me ;)
ham ipv4

/etc/shorewall/interfaces

Code:

# in the previous post you mentioned that the following showed up as invalid...so maybe leave out the hyphen???
#zone interface broadcast
ham   ham0      -
ham   ham1      -

/etc/shorewall/policy

Code:

# this is what confuses me a bit but here is how I interpreted it....
# prevent traffic from ham0, ham1, etc going to other zones????
# I would feel like forwarding is required for that but oh well...
ham all REJECT:info
# same confusion....I understand ham0 -> fw and vice versa but "all"? why all, idk...
# allow traffic to ham0, ham1, etc
all ham ACCEPT

Here is the link I'm basing the above config from http://permalink.gmane.org/gmane.com...horewall/11570

Let me know if it helps.

Also, it seems like the hamachi daemon needs to talk with the hamachi server on a UDP port 12975. http://permalink.gmane.org/gmane.com...horewall/11568

From the same link above (the first link)
/etc/shorewall/rules

Code:

ACCEPT fw net tcp 12975
# the link has a comment saying you may not need the udp rule but I think the person mixed it up...it's the udp that is used (according to the second link above) so it may be safe to leave out the tcp 12975...
ACCPET net fw udp 12975

I am still not sure about the 14 iptable i/o errors but will give it more thought.

Johng · 01-16-2013, 12:11 AM

Thank you Ken. I will be away from my computer for four weeks, so I will leave trying your suggestions until I get back. Thank you for your continuing interest in my problem.

kenneth_phough · 01-17-2013, 10:52 AM

No problem. Sorry I haven't been able to give you a definite solution yet, and appreciate your patience as we solve this together.