I switched over to Fedora a couple of days ago. I'm using the built-in firewall shipped with it but I can't find out how to enable logging of dropped packets. Among others I'd like to use psad that needs firewall logging. Is there an easy way to do this? I'm not an iptables "expert".
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I am trying to figure out what command to use to show the number of DROPPED and INVALID packets that the firewall is handling.I'm going to put these commands into a log analyzer script which will run every 15 minutes with cron. The firewall is running and operating the way I want it to. I'm running CentOS 5.4.
View 2 Replies View RelatedI've recently installed Ubunter 9.10 Server Edition to use as a NAT firewall for the lab I run. I'm using iptables to do NAT forwarding and everything works great except that, occasionally, connections seem to break. Ssh connections close with "Connection reset by peer" and HTTP connections just stall out.I believe this has to do with the firewall's internal network interface occasionally dropping packets.
View 2 Replies View RelatedI am using ubuntu 9.10. Configuring my firewall using guarddog. I have setup a rule to allow traffic OUT on port 7078 UDP, and just because i'm having problems i added an IN rule.
# Create the filter chains
# Create chain to filter traffic going from 'Internet' to 'Local'
ipchains -N f0to1
[code]....
im currently running fedora 11 on my computer and i have this old firewall called firestarter. firestarter is very outdated but it has better rules for blocking connections like IGMP does any one know how to add filter rules so i can block IGMP trace and other unknown protocols it would be cool
View 5 Replies View RelatedOn April 10, 2010, I upgraded some packages on my Ubuntu 9.04 server. This included an upgrade to "ufw 0.27-0ubuntu2". I rebooted the server, and all appeared to be fine.
Now I've noticed that UFW is not logging blocked packets since that reboot. It used to do this. It is still logging the allowed packets that I've configured it to log.
Here's what a "ufw status verbose" says code...
In my Fedora13 machine, while in mobile broadband, i can ping and skype outside, but cannot browse/yum etc. Few output that may be of relevence are here:
$ netstat -s
IP:
149468 total packets received
6 with invalid headers
16174 with invalid addresses
0 forwarded
0 incoming packets discarded
118821 incoming packets delivered
101331 requests sent out
124 outgoing packets dropped
866 dropped because of missing route .....
my NIC drives me crazy and I need some help to gather all relevant informations to file a decent bug report. Maybe someone could guide me through this process.My mainboard is an AsRock Z68 Pro3
[URL]
I use a dual-boot setup with Windows7 installed in parallel to Fedora 15-x64. Whenever I had Windows in use and jjust reboot the system into Fedora, the NIC does not work as expected. Instead it goes in an endless "em1: link up" loop which results in very low bandwith or even complete network timeouts. This happens in Firefox as well as with yum or ping.
Quote:
Originally Posted by dmesg
[ 58.763294] r8169 0000:05:00.0: em1: link up
[ 59.686773] r8169 0000:05:00.0: em1: link up
[ 61.936454] r8169 0000:05:00.0: em1: link up
[code]....
If I directly cold boot into Fedora (after the power cord has been removed and the system got completely re-initialized) there are no problems at alll and I get a fast and stable network conection. This also happens with other linux distributions, for example SysRescCD.
i have a linux server runnig oracle applications. i need to access this server from putty using ssh through internet. i did by registering my static ip with the dnydns.org and i am able to connect to the server. but now there is no security to authenticate any user as any one knowing the password can login to it.
i thought of configuring the firewall of linux server but the client ip`s are not static and they change continiously. so thought of keeping one more pc between the server and the router which will do the work of authenticating. but i am confuse as how to configure it to allow the packets coming from the internet after authenticating and to by pass the packets generated from internal LAN?
One of our RHEL 5.3 servers has trouble about 30% of the time with TCP-based communications, but it does not seem to be firewall issues. From another computer on the same switch, you can SSH to the server sometimes and other times the SSH command will just hang. When it hangs, you can often just Ctrl+C and try it again and it works. Same with HTTP connections. You'll get part of a web page and then FireFox will just hang waiting for the rest and eventually time out. Same goes for communication initiated FROM the server. SSH'ing from the server to any outside server or connecting to any web site works sometimes, but most times not. iptables if off. No other firewalls are running. Tcpdump shows communication gets so far and then stops. It does not matter whether tou run tcpdump on that server or the client connecting to it. Either way you see the connection stops working. MEANWHILE, pinging with small or large packets works flawlessly. 10,000 packets, zero drops.
View 5 Replies View RelatedI have question regarding netstat? When performing a "netstat -s" I receive the following information regarding dropped packets under IP:
IP:
93978695 total packets received
0 forwarded
0 incoming packets discarded
79472157 incoming packets delivered
65235033 requests sent out
29527 outgoing packets dropped
However if I run a "netstat -i" I have no dropped packets whatsoever: (apologies for the table format):
Kernel Interface table
Iface MTU Met RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg
bond0 1500 0 34326528 0 0 0 72755307 0 0 0 BMmRU
bond0:1 1500 0 - no statistics available - BMmRU
bond1 1500 0 28605491 0 0 0 20948952 0 0 0 BMmRU
eth0 1500 0 34199550 0 0 0 72755278 0 0 0 BMsRU
eth1 1500 0 126978 0 0 0 29 0 0 0 BMsRU
eth2 1500 0 97911 0 0 0 1 0 0 0 BMsRU
eth3 1500 0 28507580 0 0 0 20948951 0 0 0 BMsRU
lo 16436 0 34094225 0 0 0 34094225 0 0 0 LRU
I've run into a of a routing issue pertaining to packets leaving a firewall, traversing and IPSec tunnel, hitting the target and then returning via a different tunnel, finally arriving back on the source firewall but on a different interface from where it started. Once the packet has returned to the firewall it is dropped I've been unable to discover the reason for the drop. Two sides to the system, Firewall A and Firewall B. Each firewall provides the default gateway to its respective side and offers a backup IPSec tunnel to the high capacity tunnel handled internally. The Layer 3 Switch uses OSPF and takes care of the bulk of the behind the scenes routing between the sides. In case of failure the Layer 3 switches direct traffic to use the Firewall tunnels to route traffic.
View 2 Replies View RelatedI'm running a Debian Squeeze 6.0.1a box that's connected to my ISP via an L2TP connection that's managed by OpenL2TPD. The box is configured to perform NAT from local clients (on eth0) to the internet (on ppp0).
However, I'm having an issue with TCP packets that are sent from the box itself to the internet (packets originally coming from the local clients get sent and received over the internet just fine)
I'm using this Python app to test this:
Code:
#!/usr/bin/env python
import socket, time
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind(('', 5003))
s.listen(1)
while 1:
conn, addr = s.accept()
[Code]...
I'm looking for an open source/free network emulator tool that I could use on Mac OS X, to simulate a slow network connection, limited bandwidth and other network characteristics such as dropped packets etc for both UDP/TCP connections (or even on the physical layer).
I'm looking for the simplest solution that would allow me to run TCP/UDP servers and have a few clients connect to them on localhost emulating various network connections. I'm mainly wondering if I can use something like Linux's netem on Mac OS X (or even better cross-platform Windows/Linux/Mac). Perhaps I can run VirtualBox and a Linux kernel running netem, has anyone had luck with that?[URL]...
I've been receiving a LOT of log cruft ever since I installed my WUSB100V2 (using the rt2870sta community driver from the Linux kernel) and was wondering what it all meant.
Many times when these messages occur it is accompanied by slow network speeds and many DNS queries and outgoing SYNs being dropped. I have searched for documentation for these (error?) messages and have come up empty as far as what they mean or how I can stop them from occurring.
I reside on the opposite side of the building from my WAP. I have taken steps to improve the signal strength, but the signal quality hovers between 50% and 70%, sometimes dropping to 40% for unknown reasons.
My /var/log/messages:
Sep 12 05:04:40 necronomicon -- MARK --
Sep 12 05:29:48 necronomicon kernel: 0:3 LTL=0 , TL=0 L:4284
Sep 12 05:29:53 necronomicon kernel: 0:3 LTL=0 , TL=0 L:4104
Sep 12 05:30:06 necronomicon kernel: 0:3 LTL=0 , TL=0 L:4156
[code]....
with my other ethernet card problem solved, I suddenly run into this:
Code:
eth1
Link encap:Ethernet HWaddr 00:02:e3:16:37:4c
inet addr:10.0.2.1 Bcast:10.0.2.255 Mask:255.255.255.0
inet6 addr: fe80::202:e3ff:fe16:374c/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
[Code]...
This card was working perfectly fine up until....an hour ago and it started doing this. My iptables isn't blocking it somehow, because I didn't change anything. I tried reverting to an older kernel and that didn't help. It's not the network cable, it works fine in any other card. Also, the dropped packets seem to count down? It seems to go down by exactly one every time I run ifconfig, no matter the length of time in between running it.
As is known, there is a queue lies between the kernel subsystem and the network driver for incoming data. And if data come when this queue has no space for it, the data got dropped by kernel. Is there some way to see how many packets are dropped due to this buff penury? I tried netstat -s but could not find something useful. On the other hand, I found this 12176 packets collapsed in receive queue due to low socket buffer from netstat -s. I think this is something related to the per-socket buffer, but not the incoming queue between the network driver and kernel. Is this right?
View 1 Replies View RelatedAs part of server hardening process i would like to know the Best way of System Logging and Auditing.Following pointould be taken into consideration.Logging of critical eventsLogging access to critical accountsSecure storage and availability of logsReview of logsSecurity of logs
View 2 Replies View RelatedI'm running ubuntu 11.04, and using firestarter for my firewall. Logging events, all good, but I'd like to be able to (tcp)dump the packets being dropped/rejected. Wireshark is great after the event, but can I hook iptables and tcpdump together somehow so the system logs the entire packet rather than the summary when it says "no"? I've had a quick look/google, but can't find anything. I'm sure somebody must have wanted to do this before - any pointers people?
PS - will keep looking and post the answer if I find one....
Let's say I have a Linux workstation at work, behind a firewall. So even though I may have a remote access server set up on it (such as the most excellent NoMachine NX Server), I can't access it from home.
My home network happens to have a Linux server. Is it possible to ssh from work to the home Linux machine and set up a tunnel so that once I'm at home, I can run the NX client, point it to my home Linux box on some port like 9000, and have that forward through the tunnel to port 22 on my work Linux box? How would I set this up?
I have an auditing problem. I am required to be able to track user account modifications (creates, deletes, password changes, etc.) My team and I implemented auditd 1.7.17 and borrowed an existing rule set from /usr/share/doc/audit-1.7.17/nispom.rules. What we're seeing is that user account activity from the command line is retrievable by doing an 'aureport -m'. However, doing the same through the GUI, 'aureport -m' does not display the activity. So I have two questions:1. Is there another location I should be looking to find the user creation activities when using the GUI?2. Is there a way to make the activity using the GUI be captured in /var/log/audit/audit.log so 'aureport -m' can report it?Someone suggested a PAM configuration change, but was not able to tell me what change to make.
View 3 Replies View RelatedI plan to use newsbeuter for console RSS reading.This program has a config text file where I need to store my Google account password,in order to access my Google reader.I don't feel easy at making my password readable to everyone.Is there anyway I can somehow encrypt this information ?
View 1 Replies View Relatedi need to write a program in c that can sniff packets from Ethernet and distinguish RTP packets from Non-RTP packets, i have no idea what should i do
View 9 Replies View RelatedI wanted to disable root logins in console, so I searched for that. I found that if I change root's bash to "/sbin/nologin" in "/etc/passwd", root user will not be able to login. So I did that. But when I wanted to use sudo command, it didn't show me root bash, but it only do the same thing as logging in as root in single user mode (shows message that this account is disabled). So, how I can disable root logins, but keep enabled sudo command for standard users?
View 6 Replies View RelatedWe do NOT support samba on our Unbuntu servers but still zillions of windows machines are constantly trying to connect on the SMB ports. I've added a rule that drops access to destination ports 137-138 and that seems to work. But it creates many many log entries documenting that the packet has been dropped. I've been researching and cannot come up with a way to suppress logging for these drops.
View 4 Replies View RelatedUp until recently, as in a few days ago, I was using Ubuntu and had ufw managing the firewall.It's been "recommended" that iptables itself be used. Where do I do the rules go (as in a file) and how do I call those rules at startup?
View 6 Replies View Relatedat the end of my first in fedora i've seen that there is an integrated firewall. With ubuntu i used iptable but we haven't a internal gui firewall. I was looking for reviews but i couldn't found no about it because beeing new i'd like to know if this firewall is good or if is better to install iptable.
View 7 Replies View RelatedCan we use iptables as firewall instead of Juniper firewall
View 2 Replies View RelatedI've got a Shorewall (Shoreline?) firewall up and running, but it's logging to /var/log/messages. I'd much rather have it logging to another location e.g. /var/log/firewall but can't find (a clear enough) explanation on how to do this. Apparently, it varies greatly depending on the distro, the kernel, and the version of Shorewall that is running. You'd think it would be something as simple as setting a path in a config file, but apparently not. I'm running a stock Lenny kernel on the firewall machine. It comes with version 4.0.15 of Shorewall.
View 9 Replies View RelatedI'm running Fedora 12, and I need to disable the firewall from within a shell script, which rules out system-config-firewall. I tried the following:
Code:
service iptables stop
service ip6tables stop
chkconfig iptables off
chkconfig ip6tables off
but that didn't do it.
