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Suddenly external access to B3 not possible

Posted: 08 May 2014, 07:19
by CNLeonis
Hi,

my B3 serves as router + firewall + server. Software version is 2.6.0.2. The WAN port is connected to a cable modem, and there are several devices connected via LAN cable and wlan. I'm using easyfind to make external access comfortable.

Since a few days, I can't reach the B3 from outside, while the internal access still works fine. But it's not possible to get access through port 80 or port 22 (connection time out), although the ports are enabled. This is my firewall configuration:

Code: Select all

iptables -L

Chain INPUT (policy DROP)
target     prot opt source               destination         
REJECT     tcp  --  anywhere             anywhere            tcp flags:SYN,ACK/SYN,ACK state NEW reject-with tcp-reset 
DROP       tcp  --  anywhere             anywhere            tcp flags:!FIN,SYN,RST,ACK/SYN state NEW 
ACCEPT     all  --  anywhere             anywhere            state RELATED,ESTABLISHED 
ACCEPT     all  --  anywhere             anywhere            
ACCEPT     all  --  anywhere             anywhere            
ACCEPT     icmp --  anywhere             anywhere            icmp time-exceeded 
ACCEPT     icmp --  anywhere             anywhere            icmp echo-request 
ACCEPT     icmp --  anywhere             anywhere            icmp fragmentation-needed 
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:ssh 
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:www 
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:https 

Chain FORWARD (policy DROP)
target     prot opt source               destination         
ACCEPT     all  --  anywhere             anywhere            
ACCEPT     all  --  anywhere             anywhere            state RELATED,ESTABLISHED 
ACCEPT     icmp --  anywhere             anywhere            icmp fragmentation-needed 

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination
It's definitely not easyfind that is causing the trouble because sending a ping using the easyfind name points correctly to my external IP.

All this seems rather strange to me. External access used to work fine for more than one year and I didn't change my configuration at all. Therefore, I have no idea how to fix this problem. Maybe someone has any suggestions?

Thanks,
Nils

Re: Suddenly external access to B3 not possible

Posted: 08 May 2014, 08:42
by johannes
Can you connect using your IP, instead of the easyfind name? Also make sure to check from outside your network (from a 3G phone for instance) to make sure your home router/modem doesn't fool you.

Re: Suddenly external access to B3 not possible

Posted: 08 May 2014, 09:59
by CNLeonis
Using the IP doesn't work either. I have checked it from outside my network. I have also used some online port scanners and they say that I don't have any open ports on my B3.

Re: Suddenly external access to B3 not possible

Posted: 08 May 2014, 13:43
by Gordon
My guess is that the issue is not with the B3 but with the cable modem. Possible causes are that the ISP did a remote software update on the modem, resetting the forwarding rules, or that it gave your B3 a different IP address, making the forwarding rule(s) point to a non existent address.

Re: Suddenly external access to B3 not possible

Posted: 10 May 2014, 17:32
by jmilton
Hi,

I think you might want to double check Easyfind. Today it stopped working for me.

regards