Iptables domain name. 70:53 But in my config this blocks access to DNS.

Iptables domain name That is how PBR is implemented for black. box devices (unzoner. ntp. Dec 8, 2022 · Tour Start here for a quick overview of the site Help Center Detailed answers to any questions you might have Aug 17, 2012 · Just the handling of the packet by the queueing discipline. Jul 2, 2010 · Is there a way using IPTables to drop all requests coming to a particular domain name? For instance, all requests coming in to www. com certificate and fail with a certificate Oct 10, 2018 · If you are trying to limit outbound connections to DNS names, you will need to use something involved in resolving DNS. Also I cannot find why this should work in Oct 13, 2010 · So with each modem restart or ISP IP lease time expiry, you have to update iptables with the newly allocated public IP. Remember that it's ip tables, not dns tables. 0 coinhive. com as an example. I am also assuming that you're not interested in matching "foo. iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 20080 -j DNAT --to <container-ip>:80 So far so good, works as it should. iptables一般只能做对IP的访问控制，如果做域名的控制，iptables会自动解析成IP写入iptables规则中。 所以需要使用 dnsmasq+ipset+iptables dnsmasq：dns服务器，这里有两个作用，一个是做dns转发，本身不提供dns解析功能。 Dec 27, 2009 · Routing based on domain names as well as IPs is possible using iptables+ipset+dnsmasq+rt_tables toolchain. e. Here is how you use iptables to make the firewall markings: iptables -A PREROUTING -o eth0 -p udp --sport 53 -t mangle -j MARK --set-mark 1 iptables -A PREROUTING -o eth0 -p udp --dport 53 -t mangle -j MARK --set-mark 1 Modify to your liking to exclude trusted subnets and/or destinations. - Chion82/netfilter-name-set Aug 8, 2006 · If you're being spammed, attacked or accessed by these people, you have to block the IP's. To be able to filter domain names you need Level 7 filtering, which is better done with proxy or mikrotik router :) Of course there are some tricks like getting dns name resolved while applying filters, but some of modern websites have several ip addresses which could change time to time. You can read this from iptables manual: [!] -s, --source address[/mask] Source specification. Jan 30, 2018 · I want to block some https website like youtube. Imagine the host system also runs an apache2 (Port 80). Nelfeal Apr 11, 2017 · Also, if there are multiple A records for a domain name, which one would IPTables use? To accomplish what you are looking for, you would need to implement a system where the host running IPTables would periodically check what is the IP address for your dynamic host name, and then change its rules accordingly. Moreover, we briefly mentioned other tools to achieve the same objective. For example, consider a rule dynamic domain name match extension for iptables by DNS hooks. Also Apr 17, 2017 · Approach 2 will NOT work as you may think. v4 you will get an "access denied" message for rules. DNS is binary protocol, where the domain name and the record type (A, AAAA, MX) are all encoded into the DNS query, and response, packets. Georgi Sep 9, 2019 · iptables --table nat --flush iptables --table nat --delete-chain iptables --table nat --append POSTROUTING --out-interface ens224 -j MASQUERADE iptables --append FORWARD --in-interface ens192 -j ACCEPT Machine B: After configuring NAT rules in Machine A, Now able to ping 8. You need to configure this at your webserver. We covered iptables, which can handle the task, even though it’s a packet manager. See also this answer to the same question. Jan 25, 2015 · As I have learned, ufw doesn't truly allow outgoing restrictions based on domain names, which makes sense (from a performance perspective). 168. It's really annoying especially when I'm diagnosing a network issue and it just hangs because, well, there's no network. com will get the foo. com and https://bar. Improve this question. Pings still work. Apr 18, 2019 · I use this with iptables to limit certain outbound traffic (e. From my knowledge this can only be done iptables rules. I get a timeout from the client side. Your iptables rules will never change, but you can have an asynchronous process (i. Georgi Tsvetanov Tsenov. 8. Domain Name problems in CentOS hosted under VirtualBox. iptables -A OUTPUT -o eth0 -p udp --sport 53 -m string --string "google. com Since sites like blah. Therefore, you can put the filtering in the web-server configuration. Jul 27, 2020 · Learn how to use IP Sets and a simple Bash script to update your iptables rules based on a clients hostname or domain name instead of IP address. HTTP generally runs on port 80, so we restrict our pattern matching only to that port: Jul 23, 2018 · I would like my web server to refuse to answer queries to a domain name. Further, it takes a little time to decypher the packet, grab the IP address, convert the IP address in a domain name, check whether that domain name is blacklisted, and finally add that IP address to the blacklist ipset. 8 or any IP address from machine B, but unable to resolve any hostname. The Overflow Blog From bugs to performance to perfection: pushing code quality in mobile apps “You don’t want to be Apr 27, 2020 · One more also. Y ip i want to forward traffic from port 80 to the domain(www. I know that we can't block that using url rules. In Iptables I have added to my iptables file: -A INPUT -p tcp --dport 80 -m string --string "Host: mydomain. I need to be able to do this to restrict outgoing SMTP connections to the domain of my mail server (currently just using Gmail to test) and for HTTP connections to Ubuntu servers (for system updates). When you specify a domain name in an IPTables rule, the name is resolved to an IP address at the time the rule is loaded. If the domain name is an internal domain name, use the internal domain name server for the query. But I want to be able to use my default internet connection for remaining traffic and only route those certain domain names via the wireguard interface. Determine the domain name according to the rules given by namserver. If you follow the latter approach, use ipset definitions something like this: Redirect packets destined for any IP address resolved by the name domain. That is strange. Dec 13, 2023 · In this article we will show you how to block DNS requests (domain names + request types) via IPTables. With that in mind, we can easily create our iptables rule. iptables-save > /tmp/iptables. WIP. I want to allow Apr 16, 2017 · It's a new "feature" added recently to iptables that whenever one lists iptables -L the IP addresses will be replaced by a domain name from reverse DNS. IPTables Blocking Example. com will be dropped. a. Updates in this way require no reloading of iptables rules - ipsets can be updated on-the Dec 13, 2023 · Where the GET (or POST) /URL has the page you are visiting and the Host: header has the domain name. May 3, 2006 · iptables -A block_outgoing -j DROP -d ww1. HTTPS) to only those domains I know I want to use, without needing to know the IP addresses in advance. g. If you're trying to stop people visiting sites on that domain, it's a job for a HTTP filter, not iptables. domain. And, you can still block down incoming connections to the server initiated by other hosts. iptables -A INPUT -p tcp --src domain. Sep 16, 2017 · Secondly, blocking domain name using iptables is not quite effective since the name resolution works on the application layer; you make a request to a DNS server which would return ip address of the given domain in your DNS request; while iptables is more suitable to filter communication on network and transport layer. Dec 13, 2011 · You can also use domain name, enter: # iptables -A OUTPUT -p tcp -d www. myfritz. since the url is encrypted. Y:80 but i dont get good result because X. com" as an example, I have this in my /etc/hosts file: 0. com have multiple servers, with different hostnames, trying to keep track of them is a hassle. It got 1 NIC and 2 DNS-Names assigned: DNS1 (HostRecord) and DNS2 (Alias to DNS1) What I want to do is to PREROUTE not using the dport but by using the DNS-Name, so # Accept traffic on localhost: iptables -A INPUT -i lo -j ACCEPT iptables -A OUTPUT -o lo -j ACCEPT # Allow SSH from anywhere: iptables -A INPUT -p tcp --dport 22 -m state --state NEW,ESTABLISHED -j ACCEPT iptables -A OUTPUT -p tcp --sport 22 -m state --state ESTABLISHED -j ACCEPT # Accept ICMP Ping requests (incoming and outgoing): iptables -A domain-name-system; iptables; Share. HTTP transactions send the site name (i. A similar problem was discussed here, where they were trying to This means 1 second. The IPTables manual also recommends against specifying a domain name. They are not built to do base-domain filtration, you would need something more akin to a customized DNS server with RPZ zones to deny lookups from succeeding for that domain, and then point your system's DNS to that. asked Mar 3, 2016 at 15:59. Aug 11, 2018 · Following scenario; I have a homeserver that has a domain with dynamic DNS attached and i want to proxy anyone using my homeserver through a cheap VPS using iptables. com are on the same IP, then browsing to bar. example" --algo bm -j REJECT However, no rejection packet is received. Jan 10, 2016 · domain-name-system; iptables; bind; block. com -j DROP # iptables -A OUTPUT -p tcp -d facebook. name" ALGO name kmp TO 65535 But seems that does not work, because when I query that name against that server, I can see the reply and the counters remain at zero Sep 4, 2015 · Check the value of the net. v2ray is intended to be used as a proxy tool to bypass the GFW. You can find resolved IP of your domain instead of domain name. When resetting IPTables, the apt-get and wget command functions correctly and also downloads what I want. From the iptables man page: specifying any name to be resolved with a remote query such as DNS (e. The command i tried was: iptables -t nat -A PREROUTING -p tcp --dport 30033 -j DNAT -d XXXXXXXXXXXX. com Apr 21, 2020 · Because the domain name is not part IP or TCP or anything at levels 1 -> 3. Ask Question So I have ran the following commands (as root) to disable iptables and ip6tables: Jan 8, 2019 · And here is the part I'm not getting: if I add the iptables rules below, then it works. Follow edited Mar 4, 2016 at 13:29. com). com) Dec 31, 2012 · I have iptables blocking all UDP traffic at the moment, however I want to allow only certain DNS queries to get through. bridge. But once I activate this firewall, it isn't functional. org, or maybe someone could tell me a better way to keep the clocks in sync. stackoverflow) as part of the TCP payload (i. net:30033 but i get You can change the configuration per domain in the domains block. com. Nelfeal. If you list iptables rules, then it will be confusing as you can see rules that you applied with exact domain name. Y content is not equal to the domain(www. v4. 0/0 0. No dice. How to do it, a different way. 70:53 But in my config this blocks access to DNS. example. If the IP address corresponding to that domain name changes afterward, IPTables won’t automatically re-resolve and update the rule. Aug 13, 2011 · The configuration you print is correct. list will not work. On kernel 3. If the domain name is an external domain name, use the external domain name server for the Apr 15, 2013 · iptables -t nat -A PREROUTING -p udp --dport 53 -j DNAT --to 192. For example yahoo: Oct 13, 2010 · If you list iptables rules, then it will be confusing as you can see rules that you applied with exact domain name. Note: Non indicated domains in iptables. com" --algo bm -j ACCEPT I have also tried --dport 53 instead of --sport. Feb 27, 2021 · Note that neither UFW or iptables are domain-aware - they are only IP aware. 11. I have a www. Jul 12, 2017 · The domain name is resolved by the DNS and there is no way for the SSH server to know which domain you are using. 0. To get more clues about what is going wrong, add a LOG rule to the end of your iptables ruleset, as follows: iptables -A INPUT -j LOG. Mar 3, 2016 · domain-name-system; iptables; bind; Share. 0/0 udp dpt:53 STRING match "wpad. This is what I came up with. Y. com and bar. I would like to tell IPTables to block all traffic from the entire blah. Address can be either a network name, a hostname (please note that specifying any name to be resolved with a remote query such as DNS is a really bad idea), a network IP address (with /mask), or a plain IP address. You can make sure the actual configuration reflects your configuration file with "iptables -F" and "iptables-restore < conffile". Follow edited Mar 20, 2017 at 12:46. Aug 10, 2023 · It’s designed to work with IP addresses, not domain names. Feb 28, 2014 · iptables -L I list the rules in a all chains, but this tool lists host names instead of IP addresses for the rules that are saved. org, and it will allow the reply back in. Some protocols, such as http, embed the domain name in the request. Since I have a dynamic ip that changes occasionally, I wrote a script to update the rules based on the ip of my dynamic dns entry. Note that you need to run iptables-save as root, or with sudo like this: sudo bash -c "iptables-save > /etc/iptables/rules. Nov 27, 2015 · 0 0 DROP udp -- * * 0. So your DNS packets are being blocked by the INPUT chain's DROP policy, even though you clearly have iptables rules that should ACCEPT incoming UDP and TCP packets to port 53. com on port 22. You have to create an object per domain in the domains array to work and the domain name must be indicated at the name variable. rules iptables -A INPUT -p tcp -m tcp -i eth0 -s 11. So I tried to block all DNS queries which contain the Jul 25, 2022 · I have a wireguard vpn connection to access certain private services hosted on private ec2 instances. Mar 18, 2024 · In this article, we’ve talked about ways to allow traffic from our system to only a single domain. The client queries the domain name to the SmartDNS server. For example, to blacklist a domain name, say "coinhive. It works with IP's, not hostnames. First, let’s block example. Aug 1, 2013 · If your iptables is setup like so, it will allow ntpdate to make an outgoing connection to pool. ufw is just a frontend to iptables which also lacks this feature, so one approach would be to create a crontab entry which would periodically run and check if the IP Oct 26, 2018 · Create an ipset, and reference that in your iptables rules. I am trying to use string matching to find the domain name in the request, and allow it. First the client looks up the IP address from the domain name, then it communicates using the IP address. Dec 15, 2019 · I tried below command to set iptables rule based on domain name but upon execution, it actually resolve domain name and apply rule to iptables with resolved IP address. iptables -L To get clarity, save iptables rules to one file and verify. I am looking for a way to make iptables only accept requests for my domain name and reject the others. com, facebook. com iptables -A block_outgoing -j DROP -d ww2. iptables -A INPUT -p tcp --dport 53 -j ACCEPT iptables -A INPUT -p udp --dport 53 -j ACCEPT If I'm reading the above correctly, it means that I'm accepting incoming connections sent to the port 53 of my server. (You can get away with specifying a host name for a simple IP, but not, it seems, when you append a port). Therefore you can only block IP's, not domains. bridge-nf-call-iptables sysctl; if it's 0, then that's the problem -- set it to 1 and all will be well again. You can change the type of domain with the type variable to “ip” or “ip6”. I'll assume what I think you want, since the former doesn't make very much sense. Jun 18, 2014 · Maybe the answer to your question is too late, but recently I needed to solve a similar problem and google brings me here. Enjoy! Understanding DNS. This question has another almost as simple solution. I don't understand why this is needed. Lately I misconfigured my apache proxy, it is now fixed, but I keep receiving a load of requests looking like that : Jul 16, 2014 · The problem with HTTPs is that the certificate (containing the domain name) is sent before the client can send the Host: header with the requested domain name in it. You have to confirm that your old domain does not appear in any of the url request for all the sites in your domain. If anyone knows how this can be done or see's where I went wrong? Jan 16, 2015 · It appears that iptables does not like the destination address and port combination. com -j DROP. Nov 16, 2011 · Actually you don't need iptables-persistent either. blah. com), I used the following iptable: iptables -t nat -A PREROUTING -p tcp --dport 80 -j DNAT --to-destination X. One thing you might try to do is to configure a firewall (for example iptable) to drop connection to domain2. If you have https://foo. com" -j DROP But remember, this might end up blocking legitimate traffic. facebook. This prevents anything from contacting that domain no matter what IP address is points to on /sbin/iptables -I INPUT -p tcp --dport 80 -m string --algo bm --string "www. com and destined for port 8888 to port 7777. asked Mar 20, 2017 at 12:31. SmartDNS processes requests. We use the domain name instead of the IP address. Let's use google. After unsuccessful searches I wrote a small utility in C that intercepts DNS-responses, compares the domain name in it against given regex and lists matched IP addresses. As an alternative to configuring iptables and browser extensions, there is a one tool solution v2ray. 18 or later, you may need to load the br_netfilter module in order to make the above sysctl available. com". olddomain. X. iptables is a packet filter. not as part of the TCP header which is what iptables reads easily). com with X. Dec 9, 2012 · I needed iptables to allow ssh access based on domain name from my home ip but wanted to keep it closed for all other addresses. 11 --dport 5060 -j ACCEPT I would like to know how to do it using a domain name in this case would be pool. a script run out of cron, or similar) that periodically looks up the address, and updates the ipset as needed. com , and foo. 2. com iptables -A block_outgoing -j DROP -d ww3. , facebook. It supports a variety of VPN protocols including ShadowSocks, SOCKS5, HTTPS In addition, it can be configured to route traffic based on domain names. v4" If you just run sudo iptables-save > /etc/iptables/rules. iptables deals with IP, not DNS. These things has it’s own flaws and we will discuss those flaws later on this blog. com --dport 3128 -j ACCEPT Sep 15, 2020 · There is no hardcoded option for domain name filtering for iptables utility and we can easily apply iptables rules by replacing the IP address with the domain name. Check that the actual iptables configured state matches that with the "iptables -L" command. com is a really bad idea), a network IP address (with /mask), or a plain IP address Jun 4, 2015 · I am trying to use string matching to find the domain name in the request, and allow it. This is kind of hard reading, as in case I want to quickly find some IP address in the list, it is impossible. Available for all major OSs. But what I'm concerned about is the part that says "specifying any name to be resolved with DNS is a really bad idea". sqt mcjyl bhqb nhvvm fjxc hfajym fbiiq qqrlg jow lav