Questions tagged [block]

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279 views

Disk format 4kn to 512e not happening

I have pair of 6Tb SAS drives: Toshiba MG04SCA and Seagate Exos 7E8. They both came as 512e earlier and were reformatted with sg_format --format --size=4096. Then they were used in 4kn RAID-1 volume. ...
0 votes
0 answers
31 views

Trouble using nginx location block to exclude certain files from fastcgi cache

I've searched and tried lots of iterations of an nginx location block to exclude certain files from the fastcgi cache, but I can't get it to work. I understand using a location block is preferable to ...
0 votes
0 answers
88 views

Squid not blocking access to websites

I'm on Ubuntu Server 22.04.3 LTS and I'm trying to learn a bit about Squid. I installed Squid v5.7 and one of my tasks is to deny access to a list of URL's. I modified "squid.conf" file and ...
0 votes
0 answers
207 views

Postfix block spam email address

I have an smtp relay server on ubuntu 22.04.Config below: main.cf(Postfix 3.6.4) # See /usr/share/postfix/main.cf.dist for a commented, more complete version # Debian specific: Specifying a file name ...
2 votes
0 answers
1k views

What setting causes openvpn client to log on connection: "block IPv4 DNS requests from other apps"?

What setting causes openvpn to block third party DNS request, the windows client logs on connection: block IPv6 DNS requests from other apps netsh interface ip set dnsservers 5 static 192.168.100.1 ...
4 votes
5 answers
29k views

Permanently blocking a domain in iptables

Suppose I want to block Facebook permanently. To do this, I have followed following processes: #host -t a www.facebook.com Sample output: www.facebook.com has address 69.171.224.40 Find CIDR ...
5 votes
4 answers
25k views

How to block completely Windows Update on my network

I know it is not safe but I need to know how to prevent all computers in my LAN to download updates. I have squid as proxy with dansguardian and I use OpenDNS... I have put on a blacklist on ...
2 votes
2 answers
4k views

PF: Block all, but one subnet firewall rule?

I'm trying to do something that I thought would be relatively simple: Block all the traffic to a test server, other than my company's subnet. I've tried things along these lines (111.111.0.0 is my ...
0 votes
1 answer
393 views

How can I stop this kind of exim attack?

I has been search here, BUT no topic about my question (they just ask for their email was rejcted, but this time, not my email was been reject), it seem someone try to send spam out via my server, ...
1 vote
1 answer
388 views

Nginx - Block access to portion of path only, to all but specified IP range

I'm trying block access to a portion of a path via Nginx, unless the source IP is within a specified range. I think I've got this mostly working through much trial and error, but I seem to run into ...
3 votes
1 answer
2k views

apache 2.4.54 (httpd) require not ip not blocking ip addresses

So I am running apache 2.4.54 on a redhat centos 7 machine. I am using the below configuration to run my django application with mod_wsgi: # create new #LoadModule wsgi_module modules/mod_wsgi.so ...
2 votes
2 answers
2k views

iptables to block VPN-traffic if not through tun0

I have a dedicated Webserver running Debian 6 and some Apache, Tomcat, Asterisk and Mail-stuff. Now we needed to add VPN support for a special program. We installed OpenVPN and registered with a VPN ...
1 vote
2 answers
2k views

Linux swapping blocks system (freeze)

I have a problem with my Debian Servers. We run 4 different server which all have Intel CPUs and 128GB of RAM. Two of them run Wheezy, two of them run Jessie. We run a Java software on those systems ...
66 votes
7 answers
10k views

Government censors HTTPS traffic to our website. Workarounds?

I am helping run a website that has been blocked for political reasons by the same Russian agency that has previously tried blocking Telegram (RosKomNadzor). This is not the first time it happens, and ...
0 votes
1 answer
694 views

iptables: How to block UDP between devices on LAN-side of gateway (using dd-wrt firmware)

Goal: To block UDP traffic to devices on LAN-side of this gateway (using dd-wrt firmware), that communicate with internet and each other, to test specific communications applications running on each ...
1 vote
2 answers
3k views

DNSMasq wildcard top level domain/suffix

I'm running DD-WRT on my router and I need to block certain websites and all their potential suffixes, is that possible or would I have to list them all out individually? What I have is this address=...
0 votes
0 answers
692 views

How do I figure out what prevents incoming connections on a certain port?

I would like to enable SSH connections on an additional port on my machine, for reasons. It is a physical machine (not a VM), running Devuan GNU/Linux Chimaera (~= Debian 11.0 without systemd). The ...
0 votes
1 answer
1k views

How to restrict users switching from su command

How can I restrict users switching by su command? Suppose there are 3 users (root,user1 and user2) only root and user1 can switch by using su command. root or user1 should not be able to switch to ...
0 votes
0 answers
56 views

ban `./ANY/IN` DNS queries using iptables

I am getting some denied DNS queries I'd like to ban using iptables, to avoid bind to send augmented replies to the server ... and that they're simply annoying in my logs. (.): query (cache) './ANY/IN'...
0 votes
0 answers
437 views

Bind/Fail2ban how to reject requests from certain domain

Today I got my VPS stucked. Centos 7, 4 cores, Bind 9.11. From ssh I got Message from syslogd@host at Jul 18 09:46:16 ... kernel:NMI watchdog: BUG: soft lockup - CPU#0 stuck for 41s! [f2b/observer:...
0 votes
1 answer
788 views

Fail2ban with Firewalld on RHEL 8 - Fail2ban seemingly blocks IPs, but they are not really blocked

I'm running fail2ban on RHEL 8 using firewalld. According to the fail2ban log (with DEBUG level) it blocks IP addresses without any error, but in fact there are no such rules in firewalld and nftables....
2 votes
1 answer
319 views

IPTABLES - block IPs that do not complete handshake/visit webpage

i am trying to figure out how to achieve something am not sure is achievable and need help. I did my research but couldnt find credible information. Hope this question is not duplicate. SET UP: I am ...
-4 votes
1 answer
867 views

Domain blocked by ISP

ISPs blocked my domain in one country. It redirects to an IP address that the ISP uses to block access to sites it blocks. (https://ispipaddress:8080/mydomain.com) The URL cannot be accessed directly, ...
1 vote
0 answers
274 views

VMware esxi host partedUtil sector bit and block size?

Alright, things i did are: studying https://kb.vmware.com/s/article/1036609 and https://kb.vmware.com/s/article/2004299 , and also googled some other information about the "partedUtil" in ...
0 votes
1 answer
176 views

I cant block ACK packets going through port 80

I want to block nmap's ack ping probes and in order to do that, I fist need to block all incoming ack packets coming on port 80. I used this command but it didnt work: iptables -A INPUT -p tcp --dport ...
0 votes
0 answers
262 views

How should I block traffic to destination port using iptables?

I have received an abuse from my server provider and one thing which is the same is that the target on destination IPs is the SMB (445) port . How can I block destination traffic to port 445 using ...
1 vote
2 answers
4k views

Block request to certain url call from server

i have website running , that call url of some other website is there any way to block call to particular website. For eg : inside some part of my website a call is made to url like abc.com/xxx/aa ...
2 votes
0 answers
86 views

duplicate block device and UUID

Today I ran fsck on two partitions of our Ubuntu 16.04 server. Fsck has fixed various problems and afterwards I rebooted the server. After rebooting there were duplicate block device assignments with ...
2 votes
2 answers
10k views

block DNS Amplification Attack by iptables

Last time I've got warings about DNS Amplification Attack from NFOservers.com DDoS notifier 2015-12-30 23:28:52.609178 IP (tos 0x0, ttl 54, id 42635, offset 0, flags [+], proto UDP (17), length 1500)...
2 votes
0 answers
525 views

Apache PHP REST API handle/block web attack attempts

We're currently running a PHP API (all URL's get rewritten to index.php for route-handeling) on an Apache Debian server. Edit: (I think I might have landed on the wrong StackExchange for this question,...
0 votes
1 answer
1k views

Can nginx block ~20000 ips?

Can nginx block ~20.000 ips? And should i block ips (https://lists.blocklist.de/lists/all.txt) with nginx?
0 votes
1 answer
4k views

Iptables drop outgoing HTTPs GET request matches string in payload [closed]

I'm using CentOS 5.8(final), kernel 2.6.18-308.8.2, iptables v1.3.5 I want to block a HTTPs POST/GET request to outside which matches a string (defined as ABCxyz) in the POST/GET payload. I tried to ...
0 votes
1 answer
253 views

Is there a way to block internet access using iptables for particular access points

In our company we have several access points. For some of them in the production area it should be disallowed to use them for accessing the internet. The router we have has (at least) two interfaces: ...
2 votes
1 answer
831 views

In CentOS 7, is there a way to specify which block devices should be tuned with the scheduler (or ELEVATOR)?

In CentOS 6, there was /etc/tune-profiles/my-server/ktune.sysconfig with this text(I'm referring to the comments that explain what the code is doing): # This is the I/O scheduler ktune will use. ...
7 votes
3 answers
4k views

How do I unmount one of two devices mounted to the same mount point?

I accidentally left two different devices mounted on /opt: /dev/xvdf on /opt type ext4 (rw,relatime,seclabel,data=ordered) /dev/md0 on /opt type ext4 (rw,relatime,seclabel,stripe=256,data=ordered) ...
2 votes
2 answers
8k views

"Require not ip" .htaccess doesn't work in a single ip

I am having trouble with blocking an IP in .htaccess I've put Require not ip 192.168.20.218 It works, but it blocks the entire network instead of blocking a single IP. Can somebody solve this ...
1 vote
1 answer
2k views

How to Block a Domainname with random TLDs in Postfix?

Can anyone please tell me how to reject all domains with a particular name, but regardless of the TLD? I want to block all mail coming from domains named bulksender, like bulksender.com, bulksender....
6 votes
5 answers
7k views

Blocking a country (mass iP Ranges), best practice for the actual block

This question has obviously been asked many times in many different forms, but I can't find an actual answer to the specific plan I've got. We run a popular European Commercial deals site, and are ...
1 vote
1 answer
272 views

How to drop outgoing traffic based on matching string over HTTPS

I am managing a small shared hosting server. Today I received a complaint from my hosting provider that my server is sending out requests on wp-login.php pages of other websites elsewhere. I ...
0 votes
1 answer
2k views

how to disconnect users to MySQL but still allow admin login

Silly questions from a beginner: I wonder what is the best approach to : disconnect all users to MysQL but still allow console interactive connection, or admin connected from a MySQL Workbench? I ...
0 votes
2 answers
922 views

How to block access to web-hosting servers?

Is there a way to block all web-hosting servers trying to access my server? There are a lot of hacked websites used to do damage to my server and only common thing is IP of agressor (many of IP's) is ...
2 votes
1 answer
2k views

IP blocking with .htaccess in Apache 2.4 - Not Working

I want to block specific IP addresses but allow all others. I'm still struggling with this. First I modified the apache2.conf file to look like this: <Directory /var/www/> Options Indexes ...
-5 votes
2 answers
146 views

Router's Parental Controls Really Block All Internet Traffics?

I am using Asus 4G-AC53U router. When I turn ON "Parental Controls" to block a client's Internet access, does the router really block ALL kinds of Internet traffics including system's service (such as ...
0 votes
1 answer
852 views

Emails go to spam folder on email server with MS Exchange

Emails from redwerk.com email server goes in spam folder on server with MS Exchange. I had performed all kinds of server checkings (SPF, DKIM, Blacklists). Had performed checkings on https://...
2 votes
3 answers
6k views

Disable remote access for one user/database in SQL Server 2008

is this possible to disable remote access for one user or database in SQL Server 2008? Thanks
-5 votes
1 answer
9k views

MySQL : How to lock all write in all databases? [closed]

I need to block all writes (insert , update, delete) on all databases. How can I do that ? Put all database in Read Only for a period time.
1 vote
2 answers
5k views

Performance of iptables

I would like to ask you what is performance of iptables. Let's say that I whitelist and blacklist some IP addresses, I block about 10 000+ IP addresses, so every IP is like new rule. I don't know ...
0 votes
0 answers
525 views

domain redirect to STRATO.NL managed server (block?)

I have a managed server from strato.nl I have a domain on OVH and I want for my OVH domain to redirect to the managed server. I have configured the DNS so that xxx.ovh domains points to the IP of the ...
-1 votes
2 answers
76 views

Block a computer from all but 1 or 2 websites?

I'm setting up a computer for our machine shop that is intended for them to only get to a couple sites they may need while working. It needs to still be on our network so they can look at files saved ...
1 vote
1 answer
505 views

Deciphering kpartx output

I hope I've posted this in the proper place, if I haven't then please advise me on where to move the post. I've tried deciphering the kpartx output myself but now I'm sort of stuck and in need of ...