I have just installed a fresh copy of CentOS 5.3 and from the get-go, the NIC started dropping packets like crazy. I even closed the port on the switch,. moved the cable to a different port,. All yield the same "dropping packets" behavior. Zero on the errors, just dropping packets. Should I stick a diff nic instead?
View 1 RepliesI've got an odd one, running the CentOS 5.3 kernel, I'm experiencing lost packets on one of the two NICs when tested with ping. In this particular case, it's the internal NIC that causes the problem, pings from the CentOS machine to the public network over the external NIC never loses packets.(internet)<-->CentOS<--> (LAN) <--> desktop
- CentOS can ping the internet with no packet loss
- CentOS loses packets when pinging the desktop(s)
- Desktops lose packets when pinging the CentOS box
- Taking the LAN switch out of the equation still results in lost packets
- When the LAN NIC on the CentOS box "acts up", all desktops start losing packets
I've swapped out the NIC a few times for different makes/models, and I'm still getting lost packets to/from the internal network. So, I'm thinking that there's something squirrely going on higher up in the network stack. But evidently, not enough to log anything to the console or into the log files.At the moment, I'm leaning towards it being an issue with the nForce 750a SLI chipset. But it's odd that it only affects the LAN card and not the WAN card. I've even swapped the positions of the two NICs, and the problem persists on the LAN card.The other possibility is that iptables is eating packets silently, but in a random fashion.
I',m executing ping, but it didn't work, in order to find the mistake in my network I would like to know how to see the errors:
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18 packets transmitted, 0 received, +12 errors, 100% packet loss, time 17038ms, pipe 4 I want to see this +12 errors. Could I do that?
I was testing the security of my Ubuntu 10.04 64bit install by running a port scan from [URL] and I came upon some odd results. It appears that basically all my ports are closed, but only Port 646 is dropping packets silently. Furthermore, Port 80 is open.
View 5 Replies View RelatedI set up the web/backup server for our department and I'm having some major issues. Firstly, the server seems to be dropping the network connection periodically. I checked all of the logs and it appeared to be an IP6 issue as the only message that seemed to correlate with it was "eth0: no IPv6 routers present" in syslog. I added "ipv6.disable=1" to my boot options in menu.lst and this seemed to take care of the problem. However, I woke up this morning and the server was back down.
This didn't seem to take care of the problem. It seems to occur when my automatic backup scripts go through. I have several BASH backup scripts that use rysnc over SSH to backup several computers to the server and the server to my desktop at home. I was able to trigger the problem a couple of times running the backup script this morning. Now, I'm getting the following error when running the script, instead of losing the network connection:
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Sep 11 10:22:40 chemistry kernel: [ 396.892699] BUG: unable to handle kernel NULL pointer dereference at 0000000000000118
Sep 11 10:22:40 chemistry kernel: [ 396.892715] IP: [<ffffffff811426c0>] __dentry_open+0x240/0x370
Sep 11 10:22:40 chemistry kernel: [ 396.892728] PGD 1113d5067 PUD 11458c067 PMD 0
Sep 11 10:22:40 chemistry kernel: [ 396.892737] Oops: 0000 [#1] SMP
Sep 11 10:22:40 chemistry kernel: [ 396.892743] last sysfs file: /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor
Sep 11 10:22:40 chemistry kernel: [ 396.892750] CPU 1 .....
I tried booting with a previous kernel to see if that was the problem and I'm still getting this error. I've searched through all of the logs that I could think of to try to track down any software based problems and I just don't see anything. In the past, whenever I've run into such serious with a Linux box that popped up out of nowhere, it's always been a hardware failure. I've currently disabled all of the backup scripts and I'm going to see if it lasts through the weekend.
i 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 RelatedAs soon as i'm starting to copy a large file enough file (>700Mb) to my ubuntu box (connected to an Asus router via wifi) from a Windows 7 client (connected to router via ethernet cable) i get a dramatic drop in speed. upload starts at 1,0Mb/sec with a ping to ubuntu box at <1ms, and in 2 minutes it drops to 200kb/sec with a ping of over 1000ms! The ping increases with every second in a linear progression.
To exlude router as a possible problem copying to a windows 7 notebook connected to router via wifi results in an average of 2,7Mb/sec with an average ping of 150ms.
MB Model: Asus P5B Deluxe wifi
OS: Ubuntu Server 9.10 + desktop installed
Wifi configured via GUI
2. lsusb
3. wlan0
4. lsmod
I had CentOS 5.2 Upgraded to 5.3 -- when will I learn to test more. Anyway, same everything and samba won't stay up. I'm constantly doing service smb restart and then a few seconds later the shares are gone and I have to run smb restart again.
View 3 Replies View RelatedI'm having difficulties with ntpd on my CentOS 5.6 install.
It all starts well; the server connects and synchronizes with a couple of public ntp servers:
[root@toro ~]# ntpq -p
remote refid st t when poll reach delay offset jitter
==============================================================================
+ntp.networking4 193.67.79.202 2 u 1 64 377 35.652 47.102 12.349
*deepthought.doc 131.188.3.223 2 u 2 64 377 29.010 44.358 11.585
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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?
After doing a clean base install of CentOS 5.3 on a test server, I started having problems with network disconnects. While SSH into the box, I would be intermittently disconnected from the SSH session. At first I thought it was my workstation, but after running ping tests from multiple machines on the network to the test box, it became apparent that the test box was dropping packets. When I lose my SSH connection, the pings also start timing out, for a few seconds, then start again. I increased the console logging and I can see when the ethernet port goes up and down when I physically disconnect the cable, but it does not go down or lose link when the disconnects occur. I changed the NIC ports being used and had the same result. I tried with a different switch with same result. I reinstalled CentOS 5.2 and the problem went away.
Upon further investigation, I found that CentOS 5.2 is using the e1000 driver for my NICs and CentOS 5.3 is using the e1000e driver. I resinstalled CentOS 5.3, and tried using the e1000 driver instead of the e1000e but it no longer detects my NIC's... apparently they moved the support from e1000 to e1000e. I have spent the last 3 days googleing for info on this problem and have not found a solution. Any recommendations? Should I submit a bug report?
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I use wireshark (ethereal) to moniter the traffic passing through the NIC. I find that system always sends "bad checksum" TCP/UDP packets. In CentOS 5.2 this is seldom. Does your system (5.3) send "bad checksum" TCP/UDP packet ?
View 2 Replies View Relatedif am using --log-prefix "BANDWIDTH_OUT:" --log-level 7 to capture packets, I think is there a way to view these?
View 4 Replies View RelatedI've got Tyan S4989 with gigabit ethernet controller Intel Corporation 82571EB. Sometimes server starts drop packets and doesn't respond to any connections and all logs doesn't contain any errors. iptables and SELinux switched off on CentOS 5.3(2.6.18-128.1.6).
View 3 Replies View RelatedI try to set up a 5 nodes cluster and a shared Coraid Storage with conga but it fails with "Shared Storage Support" checked.The message is:'A problem occurred when installing packages: Packages of set "Clustered Storage" are not present in available repository' and it is shown under every node on the next sceen after I submit.The pc where conga runs is on the same subnet (192.168.xxx.xxx) and it has the same /etc/hosts of the other nodes.In that pc runs a proxy too and the nodes go out through it (that pc has 2 NICs)Every node (2.6.18-128.1.14.el5-xen-x86_64) is patched whith the last yum update (this morning) the same is for the pc (2.6.18-128.1.14.el5).Every node has 4 NICs , 2 NICc towards the storage the others in bonding towards the WAN.Every node is exactly alike, they have been installed with the ks.cfg generated from the first node and they all have the support for Clustering, Virtualization, and Clustered Storage.
View 1 Replies View RelatedI have a hardware device with two ethernet ports, eth0 and eth1 running Centos 5. Basically my goal is to forward packets from eth0->eth1 and eth1->eth0 as well as get a copy of these packets for analysis. If I set IP routing to do the forwarding then I won't get a copy of the packets for analysis.
View 3 Replies View RelatedI just installed CentOS 5 today. Had terminal open and got these errors:Quote:Message from syslogd@ at Wed Jul 8 12:38:33 2009 ...localhost kernel: Uhhuh. NMI received for unknown reason a0 on CPU 0.Message from syslogd@ at Wed Jul 8 12:38:33 2009 ...localhost kernel: You probably have a hardware problem with your RAM chipsMessage from syslogd@ at Wed Jul 8 12:38:33 2009
View 4 Replies View RelatedThe problems I was having earlier: [URL]seemed to be solved.
I was not getting any error messages after restart. I should have powered down fully, but did not think that it would make a difference. :(
The same issue is again occurring, but after shutdown ONLY and only on the first boot. After the first boot, a system restart will not cause any error messages. (I have rebooted at least ten or twenty times to make sure)
But after a system shutdown, the first boot hangs up and I get the
"Red Hat nash version 5.1.19.6 starting hdb: timeout waiting for DMA hdb: drive not ready for command"
errors five or six times before each boot. Also the system boots very slowly the first time.
I used the getinfo.sh all command and posted the info to the suggested site here: [URL]
Is it possible this could be a hardware issue? This is an old salvaged HDD. Ive changed everything I c an think of in the BIOS with no results.
I have used the hdparm -d /dev/hdb command and verified that dma is not being used on initial boot or after a shutoff but IS being used after a reboot...
here are the HDD settings
/dev/hdb:
multcount = 16 (on)
IO_support = 0 (default 16-bit)
unmaskirq = 0 (off)
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I installed the VSFTPD from YUM and installed the webmin module.i can connect to the server with Telnet but can�t list files.When i try to connect with a FTP client i get the following errors: An error occured openig that folder on the ftp server. Make sure you have access to that folder.
200 Switching to ASCII mode.
227 Entering passive mode (172,20,1,5,69,210)
How to i choose Users and what folders to use??
I've made a CentOS 5 x86_64 setup last year, around november/december.This system is supposed to operate as a home router/gateway, firewall, nas, small intranet/extranet server and media center.I've previously built a system using older parts (Pentium III 866MHz), and had on it CentOS 5 x86.It successfully served the same purpose (except nas and media center) for quite some time, about 1-2years, until i felt i needed better hardware (more memory, speed and disk space mainly) and 64-bit support.
Part of this intended setup isn't finished (router/gateway, firewall, media center), partially because i'm still lacking a good 1000mbps switch and a supported wireless n 3-antenna card in AP/server mode.In the previous setup, i had router/gateway, firewall and small intranet/extranet server working, with a crappy 100mbps switch (the switch is broken now).the new setup has run pretty well, it had been upgraded 2 times, etc...But since it has been installed, even before any updates, upgrades or repo additions, there has been always warnings/errors during kernel boot.I'm listing my specs, configs, versions and logs bellow. all the partitions, RAID and LVM were created during CentOS initial setup.
Hardware:
Case:1x Cooler-Master CM-690 II Advanced (RC-692-KKN2)
PSU:1x Corsair VX450W (CMPSU-450VX)
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i rebooted my centOS 5.3 server an I got the the errors below. I need to recover the information its very critical.
Loading ahci .ko module
Loading dm-mem-cache .ko module
Device-mapper: uevent: version 1.0.3
Device-mapper: ioct1: 4.11.5-ioct1 (2007-12-12) initialized: dm-devel@redhat.com
Loading dm-log. Ko module
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Im running an update through YUM from my CentOS5 64bit box and came across this error:Transaction Check
Error:
I've done some research on this and found solutions on how to rectify (i.e. reconfig YUM repositories etc.) but still same issue.
I'm running CentOS 5.3 x64 within a 32 bit version of Windows XP via VirtualBox. What I'm trying to do is install Eclipse such that I can code in both C++ and Java. I'm going to need to eventually add the OpenMP library, but that's later on. Right now, I'm just trying to get Eclipse to that point, I have the gcc and jre installed...it's just that Eclipse is not wanting to cooperate.
I did uninstall the open-jdk and install the Java SE 6u14. java version "1.6.0_14" Java(TM) SE Runtime Environment (build 1.6.0_14-b08) Java HotSpot(TM) 64-Bit Server VM (build 14.0-b16, mixed mode)
And the gcc... gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2-44) Copyright (C) 2006 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
I was able to install the Eclipse SDK using yum...
Eclipse Platform
Version: 3.2.0
Build id: M20060921-0945 (CentOS release 5 (Final))
However when I go to update it using Eclipse's update utility to install from the Eclipse Project Updates (in this case, Eclipse 3.2.2 update) I get:
Unable to complete action for feature "Eclipse Platform" due to errors.
Unable to complete action for feature "Eclipse RCP" due to errors.
Unable to create file "/usr/share/eclipse/plugins/com.ibm.icu_3.4.5.20061213.jar1249125532555.tmp". [/usr/share/eclipse/plugins/com.ibm.icu_3.4.5.20061213.jar1249125532555.tmp (Permission denied)]
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My box is centos 5.3 x86. At booting, ipsec_setup messages are coming as attached picture.
And dhcpd also comes "failed".
How to figure out why there are errors on bond0(eth0)
Transfer speed is in KB
I've installed a 500 Mb WD HD (Sata3) in my Centos 5 Server (AMD QuadCore) - Linux 2.6.18-128.el5 #1 SMP (x86_64)
Fdisk keeps failing with the following message - kernel: ata1: SError: { HostInt Handshk }
Tim Weil
Silver Spring, MD.
tweil@securityfeeds.net
When using YUM UPDATE from the prompt more than 230 items are scheduled for update however when the download process has completed I receive errors regarding Perl dependences such as:
file /usr/lib/perl5/5.8.8/List/Util.pm from install of perl-5.8.8-27.el5.x86_64 conflicts with file from package perl-5.8.8-18.el5_3.1.i386
I am unsure how to overcome this. It occurs on two different servers.
When try to yum install sendmail geting errors:
View 3 Replies View RelatedI am a complete novice when it comes to Linux, but want to learn, and installed CentOS5 on an old P4 Dell I had lying around.
Dell Dimension 8100 BIOS is version A02
Install seemed to go fine, but when I power up I get the following message
Red Hat nash version 5.1.19.6 starting
hdb: timeout waiting for DMA
hdb: drive not ready for command
this happens a few times each, then CentOS finally loads.
If Im understanding this right, DMA is direct memory access.
Is it possible the hard drive, motherboard etc does not support this?
Not sure on what is going on here. The server is RAID1 through hardware RAID. It was running an unusual high load so I rebooted it. Now it won't boot up. I am getting these errors after the CentOS boot screen:sda: Current [descriptor]: sense key: Medium ErrorAdd.Sense: Address mark not found for data field
end_request: I/O error, dev sda, sector 3040555357
device-mapper: raid1: A read failure occurred on a mirror device.
device-mapper: raid1: All sides of mirror have failed.
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