Question about SuSE firewall behavior

Question about SuSE firewall behavior

Post by Chuck Lall » Thu, 31 May 2001 21:30:11



I am running SuSE firewall and am getting the following messages repeated
several times in /var/log/messages.  I don't know what it means and if I
have something misconfigured.  

Packet log Packet log: input DENY eth0 PROTO=17 xxx.xxx.xxx.xxx:138
xxx.xxx.xxx.255:138 L=234 S=0x00 I=0 F=0x4000 T=64 (#2)
  Where xxx.xxx.xxx.xxx is my static IP address using SDSL.

What does this mean ?  Am I denying something from within my own network ?

Thanks,

Chuck

 
 
 

Question about SuSE firewall behavior

Post by nord » Fri, 01 Jun 2001 00:10:50



> I am running SuSE firewall and am getting the following messages repeated
> several times in /var/log/messages.  I don't know what it means and if I
> have something misconfigured.

> Packet log Packet log: input DENY

You ignore the following incoming packet...

Quote:> eth0

... on your first ethernet card

Quote:> PROTO=17

a UDP packet (see /etc/protocols)

Quote:> xxx.xxx.xxx.xxx:138

from your system's port 138

Quote:> xxx.xxx.xxx.255:138 L=234 S=0x00 I=0 F=0x4000 T=64 (#2)

to your subnet's broadcast address on port 138 , which is netbios (see
/etc/services)
T=64 means time to live is 64 (guess), looks like the packet really is from
your host.

Quote:> What does this mean ?  Am I denying something from within my own network ?

Looks like it. If you need it, tell your firewall to let it through. If you
don't, find out what demon is sending out broadcast packets and deinstall
it.

nordi

--
Linux - Less bugs for less bucks!

Visit http://private.addcom.de/nordi

 
 
 

Question about SuSE firewall behavior

Post by Chuck Lall » Fri, 01 Jun 2001 07:39:46


More questions:  today I found these in my /var/log/messages file

Have I been hacked ?
May 29 23:19:20 linux kernel: Packet log: input ACCEPT eth0 PROTO=6
137.208.85.85:3640 64.81.215.242:1080 L=60 S=0x00 I=63132 F=0x4000 T=43 SYN
(#38)
May 30 04:51:06 linux kernel: Packet log: input ACCEPT eth0 PROTO=6
148.206.65.145:16227 64.81.xxx.xxx32771 L=44 S=0x00 I=31100 F=0x0000 T=41
SYN (#38)
May 30 09:30:26 linux kernel: Packet log: input ACCEPT eth0 PROTO=6
61.141.101.168:1261 64.81.xxx.xxx:3128 L=48 S=0x00 I=7820 F=0x4000 T=110
SYN (#38)
May 30 09:30:27 linux kernel: Packet log: input ACCEPT eth0 PROTO=6
61.141.101.168:1261 64.81.xxx.xxx:3128 L=48 S=0x00 I=17292 F=0x4000 T=110
SYN (#38)
May 30 09:30:28 linux kernel: Packet log: input ACCEPT eth0 PROTO=6
61.141.101.168:1261 64.81.xxx.xxx:3128 L=48 S=0x00 I=22924 F=0x4000 T=110
SYN (#38)
May 30 09:30:29 linux kernel: Packet log: input ACCEPT eth0 PROTO=6
61.141.101.168:1261 64.81.xxx.xxx:3128 L=48 S=0x00 I=30348 F=0x4000 T=110
SYN (#38)
May 30 18:28:38 linux kernel: Packet log: input ACCEPT eth0 PROTO=6
212.34.211.79:3263 64.81.xxx.xxx:8080 L=48 S=0x00 I=8590 F=0x4000 T=110 SYN
(#38)
May 30 18:28:40 linux kernel: Packet log: input ACCEPT eth0 PROTO=6
212.34.211.79:3263 64.81.xxx.xxx:8080 L=48 S=0x00 I=8950 F=0x4000 T=110 SYN
(#38)


> I am running SuSE firewall and am getting the following messages repeated
> several times in /var/log/messages.  I don't know what it means and if I
> have something misconfigured.

> Packet log Packet log: input DENY eth0 PROTO=17 xxx.xxx.xxx.xxx:138
> xxx.xxx.xxx.255:138 L=234 S=0x00 I=0 F=0x4000 T=64 (#2)
>   Where xxx.xxx.xxx.xxx is my static IP address using SDSL.

> What does this mean ?  Am I denying something from within my own network ?

> Thanks,

> Chuck

 
 
 

Question about SuSE firewall behavior

Post by Manfred Bart » Fri, 01 Jun 2001 09:37:36



> More questions:  today I found these in my /var/log/messages file

> Have I been hacked ?

Just going by the logs, probably not.
But you should DENY all incoming SYN packets.

If you run squid (port 3128) then that port should be protected by a
DENY rule from outside access.  Same for any other servers you might
run.  Check with ``netstat -tupan''.

Quote:> May 29 23:19:20 linux kernel: Packet log: input ACCEPT eth0 PROTO=6
> 137.208.85.85:3640 64.81.215.242:1080 L=60 S=0x00 I=63132 F=0x4000 T=43 SYN
> (#38)
> May 30 04:51:06 linux kernel: Packet log: input ACCEPT eth0 PROTO=6
> 148.206.65.145:16227 64.81.xxx.xxx32771 L=44 S=0x00 I=31100 F=0x0000 T=41
> SYN (#38)
> May 30 09:30:26 linux kernel: Packet log: input ACCEPT eth0 PROTO=6
> 61.141.101.168:1261 64.81.xxx.xxx:3128 L=48 S=0x00 I=7820 F=0x4000 T=110
> SYN (#38)
> May 30 09:30:27 linux kernel: Packet log: input ACCEPT eth0 PROTO=6
> 61.141.101.168:1261 64.81.xxx.xxx:3128 L=48 S=0x00 I=17292 F=0x4000 T=110
> SYN (#38)
> May 30 09:30:28 linux kernel: Packet log: input ACCEPT eth0 PROTO=6
> 61.141.101.168:1261 64.81.xxx.xxx:3128 L=48 S=0x00 I=22924 F=0x4000 T=110
> SYN (#38)
> May 30 09:30:29 linux kernel: Packet log: input ACCEPT eth0 PROTO=6
> 61.141.101.168:1261 64.81.xxx.xxx:3128 L=48 S=0x00 I=30348 F=0x4000 T=110
> SYN (#38)
> May 30 18:28:38 linux kernel: Packet log: input ACCEPT eth0 PROTO=6
> 212.34.211.79:3263 64.81.xxx.xxx:8080 L=48 S=0x00 I=8590 F=0x4000 T=110 SYN
> (#38)
> May 30 18:28:40 linux kernel: Packet log: input ACCEPT eth0 PROTO=6
> 212.34.211.79:3263 64.81.xxx.xxx:8080 L=48 S=0x00 I=8950 F=0x4000 T=110 SYN
> (#38)

You can extract the rules you need from:
        <http://logi.cc/linux/minimalIPChainsRules.txt>

--
Manfred
----------------------------------------------------------------
NetfilterLogAnalyzer, NetCalc, whois at: <http://logi.cc/linux/>

 
 
 

1. Fwd: SuSe 8.0 Personal Firewall questions

,--------------- Forwarded message (begin)

 Subject: SuSe 8.0 Personal Firewall questions

 Date: Tue, 11 Jun 2002 15:54:42 -0500

 I am having trouble finding out some information on the Personal
 firewall included with SuSE 8.0, which I am running.

 The docs in /usr/share/doc/packages talks about setting up runlevels
 and such to install the firewall.

 The help says to enable the firewall when you create the modem dialup.

 I don't have a modem?

 I went into YaST2 and under Security enabled the firewall.

 How can I tell if it is running?

 Also, when I look in /var/log/firewall I get all kinds of stuff like
 this:

 Jun 10 21:49:58 linux kernel: eth0: no IPv6 routers present
 Jun 10 21:51:55 linux kernel: SuSE-FW-DROP-ANTI-SPOOF IN=eth0 OUT=
 MAC=00:50:ba:5e:37:e5:00:04:5a:d8:ca:17:08:00 SRC=192.168.1.1
 DST=192.168.1.100 LEN=40 TOS=0x00 PREC=0x00 TTL=150 ID=55654 PROTO=TCP
 SPT=3185 DPT=1026 WINDOW=5840 RES=0x00 ACK RST URGP=0
 Jun 10 21:51:58 linux kernel: SuSE-FW-DROP-ANTI-SPOOF IN=eth0 OUT=
 MAC=00:50:ba:5e:37:e5:00:04:5a:d8:ca:17:08:00 SRC=192.168.1.1
 DST=192.168.1.100 LEN=40 TOS=0x00 PREC=0x00 TTL=150 ID=55655 PROTO=TCP
 SPT=3185 DPT=1026 WINDOW=5840 RES=0x00 ACK RST URGP=0

 Jun 11 08:58:25 linux kernel: Inspecting /boot/System.map-2.4.18-4GB
 Jun 11 08:58:25 linux kernel: Loaded 12771 symbols from
 /boot/System.map-2.4.18-4GB.
 Jun 11 08:58:25 linux kernel: Symbols match kernel version 2.4.18.
 Jun 11 08:58:25 linux kernel: Loaded 3599 symbols from 51 modules.
 Jun 11 10:30:05 linux kernel: ALSA
 ../../../alsa-kernel/core/seq/oss/seq_oss_init.c:212: no device found
 Jun 11 10:56:27 linux kernel: ALSA
 ../../../alsa-kernel/core/seq/oss/seq_oss_init.c:212: no device found
 Jun 11 11:25:49 linux kernel: ALSA
 ../../../alsa-kernel/core/seq/oss/seq_oss_init.c:212: no device found

 I can understand the packet stuff, but what are OSS and alsa hits
 doing in a firewall log?

 FWIW the firewall log and the system log look very similar with all
 kinds of device traffic (ie:mounting drives etc).

 What am I doing wrong here?

 Oh yea, I am on a broadband hook up if it matters.
 tia

 flatfish

`--------------- Forwarded message (end)

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