11
votes
Environment variables of a running process on Unix?
While rather sparsely documented, the contents of /proc/<pid>/environ will only contain the environment that was used to start the process.
If you need to inspect the current state of a process'...
- 1,760
10
votes
Can tone ethernet cable into patch panel but it's not working
You can use a Fluke to test the pairs. That will tell you if the cable is bad; all the tone does is confirm that the two ends have electrical connectivity.
- 36.2k
7
votes
Accepted
Fortinet: Is there any equivalent of the ASA's packet-tracer command?
On the Fortigate you actually don't have command with capability to generate a dummy packet like on your cisco ASA. But the closest utility will be "diagnose debug flow" commands. The difference is ...
- 86
7
votes
Accepted
What to do with trailing slash in $HOME on CentOS?
The value of $HOME originates from the /etc/passwd file. You can use usermod --home /home/user user as root to change the home directory of user to be /home/user. The advantage of using usermod rather ...
- 30.7k
5
votes
Can tone ethernet cable into patch panel but it's not working
Since your talking about SOHO routers etc. I'm assuming that a tester from Fluke is way over budget to test one cable? And I've been in the same position where I've had to troubleshoot a cable without ...
- 167
4
votes
HTTPS slow/times out while HTTP is working normally
Glad you got a working solution to this. Based on what you have described, this sounds like a Path MTU Discovery Black Hole issue.
Essentially, you may well have a router on your route to the ...
- 1,173
4
votes
Best way to troubleshoot apache not starting?
I had similar problem with debug apache server on Mac OS, so decided to share my experience and save others some time
I found the following very helpful:
locate logs:
apachectl -S | grep log
in the ...
- 153
4
votes
Environment variables of a running process on Unix?
If you want to create formatted env like output of the environment variables for an arbitrary process (PID), you can create a convenient bash penv <pid> command (tailored to your OS) and add it ...
- 153
3
votes
Unable to logoff, disconnect, or reset terminal server user in production environment
I had the same issue in Windows Server 2016. The user was not able to login.
So I tried the following steps to disconnect the orphaned session:
on the CLI qwinsta lists all available sessions, ...
- 289
3
votes
Accepted
Testing VPN from same network I want to VPN into
You could use a smart phone as a WIFI access point... connect a laptop to it to do all your testing while sitting right at your desk in your office.
- 6,330
3
votes
Accepted
DNS issues after KB3200970 and KB3202790 updates installed
You were able to reproduce the issue on another PC? It seems like a networking issue.
First try to reset IP and Winsock settings and restart the PC
netsh int ip reset c:\resetlog.txt
netsh winsock ...
3
votes
Accepted
Diagnosing system which persistently recognises SATA drives but refusing to recognise SAS drive or its replacement?
I spoke to LSI (now Avago) tech support for storage, in Germany. They considered that if 2 different kinds of "known good" controller in 2 different machines both recognised all sata but not this sas ...
- 724
3
votes
How to troubleshoot Nginx 499 when it's not returning a web sockets handshake back to the client?
Fixed.
Had to replace the Classic AWS ELB with an ALB.
- 159
3
votes
Accepted
Diagnosing samba fileshare issues with TP-Link router
The most common tool that is used to troubleshoot any network-related issues is Wireshark https://www.wireshark.org/. It is free and pretty easy to use after watching a 1-5 minute related video on ...
- 6,249
2
votes
Troubleshooting apache redirects in production
To get additional debugging information for debugging Apache issues (such as redirects), you can add RewriteLog and RewriteLogLevel to the configuration. The specifics of the configurations are ...
- 21
2
votes
How to investigate unexpected Linux server shut down?
There are a number of logs files in /var/log directory (and it's subdirectories), including
/var/log/boot
and
/var/log/boot.log
Start with the files above.
- 21
2
votes
Troubleshooting ESXi hardware freeze with PCI Passthrough
Realize this question might be dated but still came up as a top google result when I hit this problem. Found a solution here so figured I'd share.
My env:
VMware ESXi 6.5
SuperMicro SYS-E300-8D
...
- 21
2
votes
Unable to logoff, disconnect, or reset terminal server user in production environment
Locate the session ID with qwinsta.
Kill all processes under the session taskkill /FI "SESSION eq 1" /F, assuming the session ID you wanted to end returned from qwinsta was 1.
This worked on Server ...
- 21
2
votes
How to investigate unexpected Linux server shut down?
You can find if system know about fact that it was going down with next commands
sudo last -1x reboot
sudo last -1x shutdown
If no info => then it could be lose of power or something else external
...
2
votes
Website inaccessible until host is pinged from client (on a class A subnet)
We had a problem similar to this issue that we solved today. A website hosted on one of our VMs would only be accessible after we pinged it. We figured out that the VM's NIC was set so it could go to ...
2
votes
Accepted
Win2012r2 Services Recovery Tab documenation refuses to launch
I see the same error on any Server 2012 R2 I checked, but I also see it on Windows 10 and Windows Server 2016 TP5. So I think there is no problem with your installation, it's a bug in the OS that ...
- 14.2k
2
votes
Why is Group Policy not applying a desktop wallpaper setting?
There could be any number of possible explanations for this.
To start ruling them out, try the following:
AD/GPO Replication - Ensure that your domain controllers can replicate between eacother (if ...
- 515
2
votes
debugging stuck apache/php thread on production server
The following instructions are Linux-centric:
Identify the faulty / stuck process
In your case, the process is in state S, meaning from man ps:
S interruptible sleep (waiting for an event to ...
- 251
2
votes
Part of LAN network connected to 1 switch freezes up periodically
First off: I believe Netgear Prosafe switches are like HP procurves, and have a limited lifetime, advanced replacement warranty - it may be worth logging the call with them as intermittent switch ...
- 427
2
votes
Part of LAN network connected to 1 switch freezes up periodically
Have you checked the firmware version on all of your equipment? There are a few versions of the Netgear switch that need to be checked. You did not list it in the OP. You can check this link here for ...
- 170
2
votes
How to diagnose end user DNS problems with my domain?
Ask them to use nslookup to test.
#> nslookup
#> server <DNS SERVER IP>
#> <HOST NAME TO TEST>
Possible issues:
Machines has a local dns cache/caching namserver that is ...
- 47
2
votes
How to determine process which makes DNS Request?
I'm afraid with normal packet captures there is no way of identifying the PID from the packets, because all you can see is what port the packet was sent from.
You can use netstat to identify who is ...
2
votes
How to determine process which makes DNS Request?
Official answer from AWS:
The GuardDuty team has confirmed this to be a false positive. The domain "libcurl.so" has been removed from the source threat intelligence list.
FYI: Passwords are not weak ...
- 255
2
votes
Accepted
How do I troubleshoot possible drive issues on ESXi 6.7?
It's not a host hard drive problem. The log file is telling you that it failed to open the virtual hard drive of the VM because of a network error.
My guess is that the backups of the VM's that are ...
- 111k
2
votes
How to query linux kernel which storage-related operations are currently being run on the level of FS / block layer / SATA controller?
In situations like this, I find that it helps to throttle the number of connections higher up the stack.
When more than, say, 100 active processes are running, they stumble over each other. They are ...
- 2,558
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