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1500 questions
50
votes
5 answers

Why is tampering with the TTL of IP dangerous?

I've been reading the iptables man-page (light bedtime reading) and i came across the 'TTL' target, but it warns: Setting or incrementing the TTL field can potentially be very dangerous and Don't ever set or increment the value on packets that…
Robbie Mckennie
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3 answers

How can I detect if a server is using SNI for HTTPS?

I'm looking for a simple way to know if a server is using the Server Name Indication SSL extension for its HTTPS certificate on a website. A method that uses either a browser or Unix command line is fine. Thanks!
spookylukey
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50
votes
5 answers

Can't connect to EC2 instance in VPC (Amazon AWS)

I've taken the following steps: Created a VPC (with a single public subnet) Added an EC2 instance to the VPC Allocated an elastic IP Associated the elastic IP with the instance Created a security group and assigned it to the instance Modified the…
Ryan Lynch
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50
votes
1 answer

How to resolve the gunicorn critical worker timeout error?

I have used nginx and gunicorn to host my website in two servers, Both server have same versions of packages and website is successfully hosted, But in one of my server gunicorn always gets timeout and I get error [CRITICAL]Worker Timeout Booting…
s.m
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50
votes
3 answers

Add directory structure to SVN, without files

Is there a way to add a directory structure to an SVN repository without adding the files contained in the folders?
fresskoma
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50
votes
7 answers

How can I successfully mount an 8-bit SCSI drive on a modern computer?

I have a number of internal 8-bit SCSI-1 drives that I'd like to archive for historical purposes. These are all the old NeXT Cubes and NeXTStations (monochrome and color) that were used by id Software to create DOOM and Quake. I'd like to donate…
Don MacAskill
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50
votes
8 answers

How much of a performance hit for https vs http for apache?

Roughly how much of a performance hit will https take compared to http for the same page? Suppose I can handle 1000 requests/s for abc.php, how much will it decrease by when accessed through https? I know this might be dependent on hardware, config,…
erotsppa
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50
votes
7 answers

How to get all fingerprints for .ssh/authorized_keys(2) file

Is there a simple way to get a list of all fingerprints entered in the .ssh/authorized_keys || .ssh/authorized_keys2 file? ssh-keygen -l -f .ssh/authorized_keys will only return fingerprint of first line / entry / publickey hack with awk: awk…
childno͡.de
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50
votes
6 answers

Where does logrotate save its own log?

I have logrotate running in an EC2 AWS machine rotating Apache logs. Once packed, Apache logs are saved into AWS S3 via s3fs. The problem is that I recently noticed that I didn't have logs rotated. In S3 I have old logs from day 48->60 but the 1->47…
enedebe
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50
votes
3 answers

Iptables, what's the difference between -m state and -m conntrack?

What's the practical difference between: iptables -A INPUT -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT and iptables -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT Which one is best to use? Thank you.
Bourne
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50
votes
7 answers

Is there a name based virtual host SSH reverse proxy?

I've grown quite fond of HTTP reverse proxies in our development environment and found the DNS based virtual host reverse proxy quite useful. Having only one port (and the standard one) open on the firewall makes it much easier for management. I'd…
ahanson
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50
votes
2 answers

How do I downgrade an RPM on a machine without 'yum'?

On a machine without yum, I have version 3.2 of a package installed and I have downloaded version 2.4 manually, how do I install the older version?
Harley
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50
votes
3 answers

How to use openssh sftp command with a RSA/DSA key specified from the command line

The Openssh ssh and scp command provied an -i command line option to specify the path to the RSA/DSA key to be used for authentication. Looking at the sftp man pages I was not able to find a way to specify the RSA/DSA key. I am looking for a way to…
Adi Roiban
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50
votes
12 answers

Unzipping files that are flying in through a pipe

Can I make unzip or any similar programs work on the standard output? The situation is I'm downloading a zip file, which is supposed to be unzipped on the fly. Related issue: How do I pipe a downloaded file to standard output in bash?
Alex
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50
votes
6 answers

How to check that an OpenVPN server is listening on a remote port without using OpenVPN client?

I need to check that an OpenVPN (UDP) server is up and accessible on a given host:port. I only have a plain Windows XP computer with no OpenVPN client (and no chance to install it) and no keys needed to connect to the server - just common WinXP…
Ivan
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