Sep 28, 2010 · The above ACL only permits inbound DNS traffic on port 53 to host x.x.x.x (which is going to be the public IP assigned to the DNS server). Now, Referring to the ACL, you should specify all other traffic that should be permitted.

Dec 6, 2017 · Your ACL is correct for udp/53, which is the port that most DNS resolution occurs on. While DNS queries normally run over UDP/53, they can also run over TCP/53. If a DNS A-record has over (approximately) 17 IP addresses, it will exceed the size of one DNS UDP packet and normal DNS resolution will use tcp/53.

Jun 16, 2011 · Starting in ASA version 8.4 (2) (Feature not available in 8.5 (1) code) , ACL entries can contain a new type of object that represents a fully qualified domain-name. This allows administrators to create ACL entries that contain a new object type fqdn that …

Access Control Lists (ACLs) define allowed source IP addresses from where servers accept incoming data or control messages. When setting up new DNS zone transfers (incoming or outgoing), you will need to update the ACL at your other DNS provider (s) to allow Cloudflare to communicate with their server (s).

Feb 26, 2024 · DNS BIND acl clause. This section describes the use of the acl (Access Control List) clause available in BIND 9.x named.conf. The acl clause allows fine-grained control over what hosts or users may perform what operations on the name server. acl clause syntax acl acl-name { address_match_list};

Mar 15, 2025 · Learn the Extended access list management through a packet tracer example. Extended access lists are flexible. They support many options and parameters to define criteria in statements. For example, you can use a source address, a destination address, a layer-3 protocol, and a layer-4 protocol.

Mar 16, 2023 · acl enforces access control policies on source ip and prevents unauthorized access to DNS servers. With acl enabled, users are able to block or filter suspicious DNS queries by configuring IP filter rule sets, i.e. allowing authorized queries or blocking unauthorized queries.

Learn what a network access control list (ACL) is and the different types. A network access control list (ACL) is made up of rules that either allow access to a computer environment or deny it. In a way, an ACL is like a guest list at an exclusive club. Only those on …

Mar 14, 2019 · With DNS-based ACLs, the client when in registration phase is allowed to connect to the configured URLs. The controller is configured with the ACL name that is returned by the AAA server. If the ACL name is returned by the AAA server, then the ACL is applied to the client for web-redirection.

To enable DNS-based ACLs on the embedded wireless controller, you need to configure the allowed URLs or denied URLs for the ACLs. The URLs need to be pre-configured on the ACL. With DNS-based ACLs, the client when in registration phase is allowed to connect to the configured URLs.