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MKDE avatar Server

no http connection after iptables changes

sj flag
MKDE

After i changed the settings in the iptables i have no http connection with lynx and no apt update works anymore but i cant see the flaw in my configuration. My iptable config:

Chain INPUT (policy ACCEPT)  
target     prot opt source               destination  
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:https  
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:http  
ACCEPT     udp  --  anywhere             anywhere             udp dpt:domain  
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:domain  
f2b-sshd   tcp  --  anywhere             anywhere             multiport dports ssh  
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:ssh  
DROP       all  --  anywhere             anywhere  

Chain FORWARD (policy ACCEPT)  
target     prot opt source               destination  

Chain OUTPUT (policy ACCEPT)  
target     prot opt source               destination  
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:https  
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:http  
ACCEPT     udp  --  anywhere             anywhere             udp dpt:domain  
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:domain  
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:ssh  
ACCEPT     all  --  anywhere             anywhere  

Chain f2b-sshd (1 references)  
target     prot opt source               destination  
RETURN     all  --  anywhere             anywhere

I cant see the problem here i have only one drop rule and the ssh connection is working.. can someone pls give a hint?

:INPUT ACCEPT [61922:10623683]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [1791:187049]
:f2b-sshd - [0:0]
-A INPUT -p tcp -m tcp --dport 20 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 21 -j ACCEPT
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -p tcp -m tcp --dport 443 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 80 -j ACCEPT
-A INPUT -p udp -m udp --dport 53 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 53 -j ACCEPT
-A INPUT -p tcp -m multiport --dports 22 -j f2b-sshd
-A INPUT -p tcp -m tcp --dport 22 -j ACCEPT
-A INPUT -j DROP
-A OUTPUT -p tcp -m tcp --dport 443 -j ACCEPT
-A OUTPUT -p tcp -m tcp --dport 80 -j ACCEPT
-A OUTPUT -p udp -m udp --dport 53 -j ACCEPT
-A OUTPUT -p tcp -m tcp --dport 53 -j ACCEPT
-A OUTPUT -p tcp -m tcp --dport 22 -j ACCEPT
-A OUTPUT -j ACCEPT
-A f2b-sshd -s 218.92.0.191/32 -j REJECT --reject-with icmp-port-unreachable
-A f2b-sshd -j RETURN
COMMIT

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diya avatar
la flag
diya
Generally I prefer the output of `iptables-save` and failing that the output of `iptables -L -v -n` - but generally when you're blocking almost all ingress traffic (with the last rule on the INPUT chain) you also block the responses for connections you're making from a system. I think you should have a `sudo iptables -I INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT` rule
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MKDE avatar
sj flag
MKDE
i insert the rule and it seems apt update gets a connection but is not able to fetch the pakets "not able to resolve" and lynx still doesnt work
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