F5 configure dns resolver. When a DNS query is sent to the IP address of the listener, BIG-IP DNS either handles the request locally or forwards the request to the appropriate resource. 4 days ago · F5 Breach and Urgent BIG-IP Fixes: What You Need to Know On October 15, 2025, F5 disclosed details of a security incident that it first detected in August. By caching DNS responses and answering queries from the cache, the BIG-IP system is able to immediately respond to subsequent client requests for the same resource. This requires to configure a DNS resolver so that Next Access can reach the Kerberos server (Active Directory) Oct 9, 2018 · Chapter 6: BIG-IP DNS/DNS services Table of contents | > This document reviews BIG-IP DNS offerings available from F5. Go to the "DNS" section and select "DNS Resolver". BIG-IP DNS Configuration About listeners A listener is a specialized virtual server that passively checks for DNS packets on port 53 and the IP address you assign to the listener. Description The DNS cache feature optimizes responses to DNS queries. The next time the system receives a query for a response that exists in the cache, the system immediately returns the response from the cache. Edit the existing DNS server or create a new one if needed. 0 and later Prerequisites BIG-IP DNS/DNS services basics BIG-IP DNS/DNS services core concepts Configuration synchronization BIG-IP DNS listeners Data centers and virtual servers Links DNS Express DNS DNS Express is an engine that provides the ability for the BIG-IP system to act as a high-speed, authoritative DNS server. In the "Root Hints Dec 16, 2020 · Description The DNS resolver is a resolver cache used by the BIG-IP system when the Bot Defense feature needs to perform DNS resolution. WAF related objects like Bot defense and SSRF protections Symptoms Without the ". Also included: general guidance on how organizations can protect themselves in the aftermath of the F5 breach by a nation-state actor. It caches DNS responses and answers subsequent queries for the same name from the cache. When you configure the DNS resolver with Forward Zones, the DNS resolver sends DNS queries that match the forward zone to one server from the list of configured servers for resolution. SEE ALSO create, delete, edit, glob, list, ltm dns cache transparent, ltm dns cache resolver, show, modify, regex, tmsh COPYRIGHT No part of this program may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or information storage and retrieval Nov 8, 2024 · Description F5® Distributed Cloud DNS (XC DNS) offers either a primary DNS service or a secondary DNS service to serve as a backup to your primary DNS services. The default value is yes. This improves DNS performance and reduces the load on external DNS servers. Next, View Configuration for it, and add your primary DNS server IP’s. SEE ALSO create, delete, edit, glob, list, ltm dns cache transparent, ltm dns cache validating-resolver, show, modify, regex, tmsh COPYRIGHT No part of this program may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or information storage and retrieval systems, for any Sep 30, 2019 · Topic When you configure the DNS cache feature, the BIG-IP system resolves DNS requests, and responds to repeated DNS queries by serving answers from the cache. When you configure the DNS resolver with a forward zone, the DNS resolver sends DNS queries that match the forward zone to one server from the list of configured servers for resolution. Retry creating the AFM address list Additional A DNS Resolver (from the network settings) is used to resolve DNS names from TMM - such as an iRule resolving an IP address or an HTTP forward proxy profile. According to the company, an intruder accessed the BIG‑IP development environment and internal engineering knowledge platforms and exfiltrated files, including some source code and vulnerability information. Additionally, zone transfer communications can be secured with TSIG keys. 1 - Create DNS Resolver ¶ Configuring a L3 DNS Resolver ¶ Note In this lab, we are adding a Single Sign-on with Kerberos Constrained Delegation to authenticate users to the back-end application (IIS server). Contents Chapter sections DNS Services features Upgrading to BIG-IP DNS 12. First, answering a DNS query Aug 26, 2021 · Hi All, So i've configured a DNS resolver "Network > DNS Resolver" as per the instructions. Sep 22, 2025 · To configure F5 XC DNS to be a secondary DNS server, go to Add Zone, then choose Secondary DNS Configuration. Feb 1, 2022 · Description How to configure a DNS-resolver for the EndPoint Management System Environment Relevant environmental factors specific to the topic APM EndPoint Management System DNS Resolver Cause None Recommended Actions The actions or steps required to address the topic covered in the description. The next time the system receives a query for a response that exists in the cache, the system returns the response from the cache. Jan 8, 2021 · To enable the BIG-IP AFM IP intelligence feature for FQDN entries, you must first configure the BIG-IP AFM system with a DNS resolver with a forward zone entry (Network > DNS Resolvers). Create Primary DNS This procedure will show you how to replace your current DNS server (s) with Distributed Cloud DNS servers. You can configure the DNS cache feature on BIG-IP systems licensed for DNS Services. With now 3 sorts of DNS on my BIG-IP (Kernel, GTM and now the DNS Resolver) how do I run a test into the DNS Resolver to prove this config is working before I use it in anger in production? (I'm trying to setup a socks proxy which insist on this config) Dig for example Lab 2. Explore five methods for service discovery in NGINX and NGINX Plus that use DNS records, including SRV records in NGINX Plus R9. 4 days ago · Home Security Cyber Attacks Hackers stole source code, bug details in disastrous F5 security incident – here’s everything we know and how to protect yourself CISA has warned the F5 security incident presents a serious threat to federal networks A DNS Resolver configured with a forward zone will forward any queries that resulted in a cache-miss (the answer was not available in the cache) and which also match a configured zone name, to the nameserver specified on the zone. The transparent cache contains messages and resource records. A transparent cache in the BIG Jan 26, 2021 · The net dns-resolver should be configured via tmsh. 4 days ago · We recommend enabling BIG-IP event streaming to your SIEM and provide step-by-step instructions for syslog configuration (KB13080) and monitoring for login attempts (KB13426). Dec 8, 2021 · Once that is created then you will need to set a Global Context DNS Resolver in the AFM Options menu, go to Security > Options > Network Firewall > Firewall Options Under the section for FQDN Resolver select the DNS Resolver created above. . The BIG-IP system uses two sources of information to resolve hostnames: the hosts file and DNS. DNS configuration found within the system is for the Linux/Management part of the device. With DNS Express configured, the BIG-IP system can answer DNS queries for a DNS zone and respond to zone transfer requests from specified DNS nameservers (clients). Log into Console and perform the following: Step 1: Navigate to DNS management and create a primary zone. Configuration details are in the tmsh reference, but the example configuration I used in my test box is below. If no nameservers are specified on the zone, an automatic SERVFAIL is returned. Choose a refresh interval and then click Update. Nov 21, 2024 · Description You need to configure DNS name resolution for ASM/Adv. DNS ¶ Navigate to System -> Configuration -> Device -> DNS Because we’re using FQDNs in our iRules and DNS pools, we’ll need a DNS resolver (s) that the BIG-IP can use to resolve them. Feb 21, 2020 · To configure the GTM (Global Traffic Manager) to perform name resolution using specific external public IPs, you can follow these steps: Log in to the GTM configuration utility. ” 4 days ago · Detailed steps Tenable customers can take immediately to address the urgent F5 BIG-IP breach. This enhances DNS performance in two significant ways. When F5 DNS resolver cache is a feature that enables BIG-IP system to resolve DNS queries itself using either an iterative or a recursive method. Under "Name Server Configuration," you should see a list of configured DNS servers. Can you explain to me what it is? And can you give me an example of configuration? Tank's in advance. Prerequisites You must meet the following prerequisites to use this procedure: You have administrative access to the BIG-IP system. Typically, you configure a resolver cache where the BIG-IP system either acts as the LDNS for clients or is in the LDNS resolver path for clients. But my stats aren't incrementing. Apr 27, 2025 · Configuration Creating and managing zones involve creating a primary DNS zone and a secondary zone, configuring settings such as records, encryption mechanism, etc. You can configure a transparent cache on the BIG-IP ® system to use external DNS resolvers to resolve queries, and then cache the responses from the resolvers. Jul 8, 2021 · Description The DNS resolver is a resolver cache that provides DNS resolver functionality for a variety of BIG-IP features and modules. " forwarding zone configured in the default DNS resolver "f5-aws-dns" certain features may not work. For more information, refer to K12140128: Overview of the DNS resolver. May 21, 2019 · In order to configure the WebScraping, F5 asks to configure the DNS resolver. Creating a DNS resolver You configure a DNS resolver to resolve DNS queries and cache the responses. Jul 8, 2021 · Additionally, the DNS resolver does not perform prefetch to keep entries in the cache or prevent them from expiring. This will enhance your visibility and alerting for admin logins, failed authentications, and privilege and configuration changes. Oct 9, 2015 · F5 does not recommend or support configuring BIND nameservices on the BIG-IP system for use as a resolver or forwarder by other client systems. In parallel, F5 released a 5 days ago · Thousands of customers imperiled after nation-state ransacks F5’s network Risks to BIG-IP users include supply-chain attacks, credential loss, and vulnerability exploits. fsc ktwtw crnya i2rrif jqy5 o4qvp5q msrkvi i1k qbslgdkw 29