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twlilinux 06-17-2008 11:39 AM

netstat interpretation
 
Hi, I have a netstat -a report from my server.
I know the ssh, and it's needed. But what about sunrpc? I just want to set up a lamp server so I don't need nfs. Is is safe to turn it off? Also what's auth?

Sorry for the plethora of questions. I'm holding on to my Linux Bible 2005 and praying for protection from internet daemons :jawa:

Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 0 *:sunrpc *:* LISTEN
tcp 0 0 *:auth *:* LISTEN
tcp 0 0 localhost:smtp *:* LISTEN
tcp 0 0 *:40831 *:* LISTEN
tcp6 0 0 *:ssh *:* LISTEN
tcp6 0 784 #servername:ssh #myip:1822 ESTABLISHED
udp 0 0 *:32768 *:*
udp 0 0 *:sunrpc *:*
udp 0 0 *:628 *:*
Active UNIX domain sockets (servers and established)
Proto RefCnt Flags Type State I-Node Path
unix 2 [ ] DGRAM 3163 @/org/kernel/udev/udevd
unix 2 [ ACC ] STREAM LISTENING 5416 /var/run/acpid.socket
unix 6 [ ] DGRAM 5329 /dev/log
unix 2 [ ] DGRAM 5817
unix 2 [ ] DGRAM 5710
unix 2 [ ] DGRAM 5546
unix 2 [ ] DGRAM 5344

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anomie 06-17-2008 12:02 PM

Try netstat with the options: -ltup (listening only, tcp, udp, display program name) Also look at the -n option.

That should be a little easier to interpret. To get more info about the registered service ports:

Code:

# egrep 'sunrpc|^auth' /etc/services
sunrpc          111/tcp        portmapper      # RPC 4.0 portmapper TCP
sunrpc          111/udp        portmapper      # RPC 4.0 portmapper UDP
auth            113/tcp        authentication tap ident
auth            113/udp        authentication tap ident

(You can probably shut these off safely for a strictly LAMP server.)

twlilinux 06-17-2008 02:57 PM

netstat -ltup

I have Craig's portsentry software that blocks portscanners. Other than that, I also have ssh. It's strange, I though ssh works in port 22, but it appears here as tcp6 2070 :confused:
Then, there's the sunrpc. I'm strickly hosting a lamp server, so what would be a good way of disabling sunrpc service?

Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 *:tcpmux *:* LISTEN 2828/portsentry
tcp 0 0 *:20034 *:* LISTEN 2828/portsentry
tcp 0 0 *:32771 *:* LISTEN 2828/portsentry
tcp 0 0 *:32772 *:* LISTEN 2828/portsentry
tcp 0 0 *:40421 *:* LISTEN 2828/portsentry
tcp 0 0 *:32773 *:* LISTEN 2828/portsentry
tcp 0 0 *:32774 *:* LISTEN 2828/portsentry
tcp 0 0 *:31337 *:* LISTEN 2828/portsentry
tcp 0 0 *:ircd *:* LISTEN 2828/portsentry
tcp 0 0 *:systat *:* LISTEN 2828/portsentry
tcp 0 0 *:5742 *:* LISTEN 2828/portsentry
tcp 0 0 *:imap2 *:* LISTEN 2828/portsentry
tcp 0 0 *:finger *:* LISTEN 2828/portsentry
tcp 0 0 *:netstat *:* LISTEN 2828/portsentry
tcp 0 0 *:sunrpc *:* LISTEN 1781/portmap
tcp 0 0 *:54320 *:* LISTEN 2828/portsentry
tcp 0 0 *:sieve *:* LISTEN 2828/portsentry
tcp 0 0 *:27665 *:* LISTEN 2828/portsentry
tcp 0 0 *:auth *:* LISTEN 2125/inetd
tcp 0 0 *:ingreslock *:* LISTEN 2828/portsentry
tcp 0 0 *:nntp *:* LISTEN 2828/portsentry
tcp 0 0 *:socks *:* LISTEN 2828/portsentry
tcp 0 0 *:12345 *:* LISTEN 2828/portsentry
tcp 0 0 localhost:smtp *:* LISTEN 2113/exim4
tcp 0 0 *:12346 *:* LISTEN 2828/portsentry
tcp 0 0 *:635 *:* LISTEN 2828/portsentry
tcp 0 0 *:49724 *:* LISTEN 2828/portsentry
tcp 0 0 *:uucp *:* LISTEN 2828/portsentry
tcp 0 0 *:40831 *:* LISTEN 2148/rpc.statd
tcp6 0 0 *:ssh *:* LISTEN 2070/dropbear
udp 0 0 *:640 *:* 2832/portsentry
udp 0 0 *:32768 *:* 2148/rpc.statd
udp 0 0 *:641 *:* 2832/portsentry
udp 0 0 *:who *:* 2832/portsentry
udp 0 0 *:1 *:* 2832/portsentry
udp 0 0 *:32770 *:* 2832/portsentry
udp 0 0 *:32771 *:* 2832/portsentry
udp 0 0 *:32772 *:* 2832/portsentry
udp 0 0 *:32773 *:* 2832/portsentry
udp 0 0 *:32774 *:* 2832/portsentry
udp 0 0 *:echo *:* 2832/portsentry
udp 0 0 *:discard *:* 2832/portsentry
udp 0 0 *:snmp *:* 2832/portsentry
udp 0 0 *:snmp-trap *:* 2832/portsentry
udp 0 0 *:54321 *:* 2832/portsentry
udp 0 0 *:700 *:* 2832/portsentry
udp 0 0 *:37444 *:* 2832/portsentry
udp 0 0 *:tftp *:* 2832/portsentry
udp 0 0 *:31335 *:* 2832/portsentry
udp 0 0 *:31337 *:* 2832/portsentry
udp 0 0 *:sunrpc *:* 1781/portmap
udp 0 0 *:628 *:* 2148/rpc.statd
udp 0 0 *:34555 *:* 2832/portsentry
udp 0 0 *:635 *:* 2832/portsentry

-------
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anomie 06-17-2008 03:12 PM

Quote:

Originally Posted by twlilinux
I though ssh works in port 22, but it appears here as tcp6 2070 :confused:
...

Code:

Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address          Foreign Address        State      PID/Program name 
...   
tcp6      0      0 *:ssh                  *:*                    LISTEN    2070/dropbear     
...


No, you are confusing the PID with the service port. The PID is 2070, and the service port is 'ssh' (which resolves to tcp port 22 in /etc/services). If you want to see a numeric port, you need to use the -n option.

Quote:

Originally Posted by twlilinux
Then, there's the sunrpc. I'm strickly hosting a lamp server, so what would be a good way of disabling sunrpc service?
...

Code:

Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
...
tcp 0 0 *:sunrpc *:* LISTEN 1781/portmap
...


Shut off portmap.

twlilinux 06-17-2008 03:33 PM

you bet! ty for the advice

-------
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unSpawn 06-17-2008 04:12 PM

Also Portsentry is (AFAIK) abandoned and deprecated. If you want "just" portscan logging see PSAD, if you'd like and IDS see Snort.

twlilinux 06-17-2008 04:59 PM

Well, I got port sentry from Linux Bible 2005. Wow... 3 years and it's already deprecated.

-------
My favorite websites:
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Ask and answer Linux questions.
Read free books without walking to the library.


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