Questions tagged [block]
The block tag has no usage guidance.
135
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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 ...
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0
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0
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228
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firewall-cmd block outgoing connection to an ip list
I have searched a lot about this, this is possible to have many of these commands one for each ip:
/usr/bin/firewall-cmd --direct --add-rule ipv4 filter OUTPUT 0 -d ::FFFF:85.185.0.0/112 -j REJECT
/...
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26
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Block windows 10 updates (off the computer)
I have a Windows 10 computer that is running software that I cannot service'ize. My problem is that I have followed every known process for disabling, discontinuing, or stopping Windows from auto ...
2
votes
1
answer
920
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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
...
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1
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287
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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, ...
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1
vote
1
answer
327
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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 ...
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1
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543
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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 ...
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509
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 ...
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52
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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'...
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357
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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
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1
answer
628
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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
301
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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 ...
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0
votes
1
answer
1k
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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 ...
2
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0
answers
1k
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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 ...
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65
votes
7
answers
9k
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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 ...
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1
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501
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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
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0
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238
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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 ...
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1
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149
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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 ...
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211
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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 ...
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2
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0
answers
75
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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 ...
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0
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444
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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,...
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800
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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?
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1
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221
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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: ...
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2
votes
1
answer
751
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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. ...
- 125
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1
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2k
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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....
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1
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1
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256
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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 ...
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2
votes
1
answer
2k
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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 ...
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-5
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2
answers
141
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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 ...
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662
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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://...
1
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2
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5k
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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 ...
- 287
-1
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2
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71
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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 ...
2
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2
answers
7k
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"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 ...
7
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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)
...
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1
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1
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484
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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 ...
1
vote
1
answer
94
views
Block Clients based on RTT
I am running an application on my Debian server, which uses IPv4 and UDP for data communication.
I would like to block every client for a short while, that has a Round Trip Time above 140ms.
...
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0
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274
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Dealing with big blocklists: Is it better to DNS Blackhole or block at firewall level
Setting up some new protections for networks and I've found myself with two different options.
Due to the size of the lists (easily 2,500,000+ domains) is it better to setup DNS servers to blackhole ...
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1
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5
answers
609
views
How do you mitigate LAN clients from participating in DDOS?
Most references I've read about mitigating DDOS involve edge routers.
However, is there anything you can do to mitigate your LAN clients from unknowlingly participating in a DDOS ?
Like blocking ...
user403619
0
votes
1
answer
4k
views
How can I block all HEAD requests to urls that contain a substring on Apache?
A server I administer is being pounded with a poorly coded AWS-built bot that switches IPs constantly and appears to be stuck in a recursive encoding loop. The only consistent fingerprint I can see is ...
- 420
1
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1
answer
2k
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How to block a small IP range in csf
I'm looking for a way to block a small ip range in csf, e.g. 151.80.31.103 to 151.80.31.115
I know how to block each ip by issuing a cmmand csf -d IP, but it is a lot more effective to have a way to ...
- 229
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2
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860
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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 ...
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1
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575
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How to prevent an openly recursive DNS server from being abused for DNS amplification [closed]
I have a business need to provide an open and recursive DNS. This DNS has of course been heavily abused by DNS amplification attacks, resulting in 5-10 Mbps sustained outbound load only caused by ...
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2
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2k
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Does the bash usleep block? Or will it yield to other threads? [closed]
I understand there is a usleep command in bash. Is this a "busy" or "blocking" sleep? Or will this yield time to other processes?
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509
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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 ...
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1
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324
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Postfix Virtual Domain - mail is send by second server [duplicate]
i setup postfix on a VPS with two domains (each one with own ip)
domain1 - 194.xxx.xxx.1
domain2 - 194.xxx.xxx.2
when i send a mail via domain2 - i am getting dmarc reports that the mail uses the ...
- 101
1
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2
answers
3k
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Block direct IP connections to Apache web server [duplicate]
I need to figure out how to block direct IP access to my website.
Example: I want it so that when people type my IP address 1.2.3.4 into the browser it doesn't work, but when they type www.example....
1
vote
2
answers
4k
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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
...
- 113
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2
answers
2k
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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 ...
- 247
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47
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Avaya switch - need to block port 25
Situation:
In QA-DEV Lab environment I need to block port 25 for the egress traffic on AVAYA ERS5510-48T switch.
Question:
How do I do it using EDM aka Web Interface? Couldn't find anything in ...
0
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0
answers
681
views
How to block device trying to connect to your wifi
In my log-file I see that hostapd shows that a device is continuously trying to connect and disconnect which slows down the network & pollutes the log-file and.
Anyone knows how to block a device ...
user332390
2
votes
2
answers
10k
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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)...
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