Take the 2-minute tour ×
Ask Ubuntu is a question and answer site for Ubuntu users and developers. It's 100% free, no registration required.

I just applied a bunch of recommended updates this morning (which seems to have upgraded the kernel to 3.8.0-32.47), and suddenly I cannot connect to the machine on port 80 (http) or 22 (ssh). Ping still works. In addition, my syslog and kern.log are filling up with messages like

Oct 22 10:43:27 mu kernel: [ 4041.036862] Inbound IN=eth0 OUT= MAC=6c:62:6d:c8:b0:d3:18:03:73:34:81:b8:08:00 SRC=192.168.212.43 DST=192.168.212.56 LEN=48 TOS=0x00 PREC=0x00 TTL=128 ID=17389 DF PROTO=TCP SPT=59502 DPT=80 WINDOW=8192 RES=0x00 SYN URGP=0 

I can connect to the web server locally, so this smells like a firewall issue to me. I've tried:

  • doing "reset firewall" from inside GUFW
  • doing "sudo ufw allow 80" and "sudo ufw allow 22" from the command line

and that is not working. So I went and looked at "sudo iptables -L", and I'm getting this, but I don't understand the output (I have hidden my employer's domain with "example.com")

Chain INPUT (policy ACCEPT)
target     prot opt source               destination         
ACCEPT     tcp  --  ad1.example.com  anywhere             tcpflags:! FIN,SYN,RST,ACK/SYN
ACCEPT     udp  --  ad1.example.com  anywhere            
ACCEPT     tcp  --  ad2.example.com  anywhere             tcpflags:! FIN,SYN,RST,ACK/SYN
ACCEPT     udp  --  ad2.example.com  anywhere            
ACCEPT     tcp  --  ad3.example.com  anywhere             tcpflags:! FIN,SYN,RST,ACK/SYN
ACCEPT     udp  --  ad3.example.com  anywhere            
ACCEPT     all  --  anywhere             anywhere            
ACCEPT     icmp --  anywhere             anywhere             limit: avg 10/sec burst 5
DROP       all  --  anywhere             255.255.255.255     
DROP       all  --  anywhere             192.168.212.255     
DROP       all  --  base-address.mcast.net/8  anywhere            
DROP       all  --  anywhere             base-address.mcast.net/8 
DROP       all  --  255.255.255.255      anywhere            
DROP       all  --  anywhere             0.0.0.0             
DROP       all  --  anywhere             anywhere             state INVALID
LSI        all  -f  anywhere             anywhere             limit: avg 10/min burst 5
INBOUND    all  --  anywhere             anywhere            
LOG_FILTER  all  --  anywhere             anywhere            
LOG        all  --  anywhere             anywhere             LOG level info prefix "Unknown Input"
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:http
ufw-before-logging-input  all  --  anywhere             anywhere            
ufw-before-input  all  --  anywhere             anywhere            
ufw-after-input  all  --  anywhere             anywhere            
ufw-after-logging-input  all  --  anywhere             anywhere            
ufw-reject-input  all  --  anywhere             anywhere            
ufw-track-input  all  --  anywhere             anywhere            
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:http

Any idea what I've done wrong? Or how to fix it? (I think I'm about to learn a lot about iptables.)

UPDATE

Unsurprisingly, other services on the machine (MySQL) are not responding either. nmap is telling me that the ports are open, tho

chris@mu:/var/log$ nmap 192.168.212.56

Starting Nmap 6.00 ( http://nmap.org ) at 2013-10-22 10:55 EDT
Nmap scan report for sentry (192.168.212.56)
Host is up (0.00030s latency).
Not shown: 993 closed ports
PORT     STATE SERVICE
22/tcp   open  ssh
80/tcp   open  http
111/tcp  open  rpcbind
139/tcp  open  netbios-ssn
445/tcp  open  microsoft-ds
3306/tcp open  mysql
5666/tcp open  nrpe
share|improve this question

1 Answer 1

I finally found "sudo iptables -F" which erased all the firewall rules (it's a dev machine, so I don't really care), and now everything is accessible.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.