High-defense DNS operation and maintenance manual: daily monitoring and troubleshooting guide

at the moment of increasingly frequent network attacks, high-defense DNS is the core infrastructure to resist DDoS attacks and ensure the stability of domain name resolution, and its operation and maintenance quality is directly related to business continuity. Many operation and maintenance personnel are often in a hurry when high-defense DNS abnormalities occur due to the lack of systematic monitoring methods and fault handling ideas. This article will sort out a set of landing high-defense DNS operation and maintenance solutions for operation and maintenance personnel from the perspectives of daily monitoring, fault investigation, and operation and maintenance specifications, to help you quickly locate problems and ensure stable service.

How to build a high-defense DNS daily monitoring system?

perfect monitoring is the key to find high-defense DNS abnormalities in advance. Only by building a monitoring system covering core indicators can we give timely warning in the budding stage of attacks or failures.

1, core performance indicators monitoring

need to focus on monitoring the high-defense DNS resolution delay, success rate, concurrent requests three major indicators. Resolution delay should be controlled within 50ms, once the threshold is exceeded, the network link or node load should be checked immediately; the resolution success rate should be maintained above 99.99%, if there is a continuous decline, to check the domain name configuration or node operating status; the number of concurrent requests needs to set a reasonable threshold, when the sudden increase often means that there is an attack or business traffic surge.

2, real-time monitoring of attack situation

the core value of high-defense DNS is to resist attacks, so it is necessary to monitor the type and scale of attack traffic in real time, including DNS amplification attacks, domain name hijacking attacks, etc. The operation and maintenance personnel can view the number of request packets per second and the proportion of abnormal requests through the attack analysis panel that comes with high-defense DNS. Once the attack characteristics are detected, the linkage protection strategy needs to be automatically adjusted, such as opening the request frequency limit and enabling domain name cache reinforcement.

Second, how to quickly troubleshoot the common faults of high-defense DNS?

high-defense DNS operation process will inevitably appear abnormal analysis, service interruption and other failures, master the standardized troubleshooting process, can greatly shorten the failure recovery time.

1, parsing failure troubleshooting

when the user feedback domain name can not be resolved, first through the local dig command to test the high-defense DNS resolution results, to determine whether the global failure or local problems. If the global resolution fails, you need to check whether the high-defense DNS node is offline, domain name filing status is normal; if only the local area is abnormal, to check the corresponding node's network link congestion, whether subject to regional targeted attacks.

2, service interruption troubleshooting

if the high-defense DNS service is interrupted, the first step is to confirm the server hardware status, check whether the CPU, memory, disk overload or failure; the second step is to check whether the protection policy is misconfigured, such as whether the request interception rules are too strict; The third step is to contact the high-defense DNS service provider to confirm whether there is a backbone network failure, and quickly locate the root cause of the problem with the help of the service provider's technical support.

What are the core specifications for the daily operation and maintenance of high-defense DNS?

In addition to passive monitoring and fault handling, daily active operation and maintenance specifications are the basis for ensuring the long-term stable operation of high-defense DNS, which can effectively reduce the probability of failure.

1, configuration change approval and rollback

high-defense DNS, such as domain name record modification and protection policy adjustment, must go through the approval process to avoid misoperation affecting the service. Before the change, the effect needs to be verified in the testing environment. After the change, the analysis indicators should be monitored in real time for more than 1 hour, and the original configuration should be saved. Once an abnormality occurs, it can be rolled back immediately to minimize the impact.

2, regular backups and drills

to backup the high-defense DNS domain name configuration, protection strategy and other core data every week, backup files need to be stored in off-site servers to prevent data loss due to local failures. In addition, a fault drill should be carried out every quarter to simulate high-defense DNS node failures, large-scale attacks and other scenarios to test the emergency response speed and fault handling capabilities of the operation and maintenance team.

4. How to continuously optimize the performance of high anti-DNS?

with the expansion of business scale and the upgrade of attack methods, the performance of high-protection DNS needs to be continuously optimized to meet the growing business needs and protection requirements.

1, node layout optimization

adjust the node layout of high-defense DNS according to the user distribution, add edge nodes in the area where users are concentrated, shorten the length of the resolution link, and reduce the resolution delay. At the same time, it is necessary to regularly detect the network quality of each node, eliminate the nodes with large network fluctuations and high load, and ensure that each node can efficiently handle the resolution request.

2, protection strategy fine adjustment

based on historical attack data, fine-tuning the protection strategy of high-defense DNS. For example, for high-frequency DNS amplification attacks, request packet size limits can be set; for domain name hijacking attacks, DNSSEC domain name signature verification can be turned on. In addition, according to the peaks and troughs of business traffic, the request frequency limit threshold should be dynamically adjusted to ensure the protection effect without affecting normal business access.

To sum up, the operation and maintenance of high-defense DNS is a systematic project. It is necessary to start with building a complete monitoring system, master standardized troubleshooting processes, implement daily operation and maintenance specifications, and continuously optimize performance. Only by combining these links can we maximize the protection value of high-defense DNS, provide stable and efficient domain name resolution services for business, and calmly deal with various network threats and business challenges.