Lightnin' Junk

Dr Stephen Vincent

Address: 5 Upward St, Cairns City QLD 4870, Australia

The Sheriff's office is a full service law enforcement and corrections organization whose goal is to protect the citizens of Macomb County

Mysterious goons chase teenage slacker Angelino through chaotic Dark Meat City as he uncovers secret powers that could be the key to saving the world Watch

Russia has a surface area of 17,075,200 square kilometers, while planet Pluto was estimated to be 16,647,940 square kilometers After the New Horizons mission, Pluto was found to be slightly larger than estimated, making its surface area 17,646,012 square kilometers, which is just a bit larger than Russia

DNS proxy is used to manage DNS queries and forward requested queries to specific name server. It forwards DNS query and response to DNS server and DNS client respectively. DNS Proxy stores client queries in the device which speed up the traffic connection for repeated queries. In short it maintains a cache in the device database and uses it for recurring connections.

Let’s discuss DNS Proxy Cache

Caching option allows DNS proxy to unburden remote DNS servers and speed-up response time for DNS lookups.

When someone initiates connection to a DNS server, a DNS query is resolved by a DNS proxy and the corresponding request is saved in the device’s DNS cache. This stored cache helps the device to resolve following queries from the same domain/webpage and avoid network latency delay.

Sometimes proxy cache is not configured in the device, in that scenario client machine query directly hits connection to configured DNS server which increase delay in response time and degrade connection performance

Figure 1.1 illustrate the whole process step-by-step

Obviously, we should use DNS-Proxy to avoid network latency. It’s a universal fact that most of the DNS-Proxy is deployed to get faster response. However, another factor which DNS-Proxy plays is to secure your network from malicious attack. How…?

Let’s understand through a diagram. Fig 1.2

DNS Proxy with Split DNS

We can split DNS query based on interface and hostname. We can deploy a name server in the network and assign domain names with them. When a user query initiates a query to the assigned domain name, the server redirects request to associated name servers. Each DNS proxy must be associated with the interface, which means if the DNS proxy feature is not configured on the firewall, all traffic forward to firewall/switch/router (all L3 network devices) will be dropped.

Figure 1.3 shows how DNS proxy is placed in the split domain topology based on Name Server

Allows you to configure static FQDN-to-IP address mappings that store in Palo alto firewall cache and revert to host without sending connection request to DNS. Example we can add the URL ipwithease.com whose IP address is 156.10.1.122. Response comes back from the firewall without forwarding the query to the DNS server. It reduces response time and makes connections faster.

Allows you to add customised domain names and matching primary and secondary DNS servers to resolve queries that match the rule. The firewall searches for a match in the DNS proxy if the domain name is not available in the DNS proxy cache and redirects the query to a respective DNS server based on the match policy. If no match is found in DNS proxy rules, the firewall sends the query to the default DNS primary and secondary servers. Example: – when traffic comes for public.com it will redirect to DNS server 108.10.1.1. Moreover, if in case 108.10.1.1 is not responding, it will forward to global DNS 8.8.8.8

Go to Network🡪 DNS Proxy🡪 Add🡪DNS Proxy Rule (Group-1, Group-2)

Add inputs in DNS Proxy Rules and commit the changes.

DNS proxies are useful in a network where a split traffic model is required. Caching feature in DNS proxy helps to reduce query response time, avoid latency, and makes the network more secure which prevent attacks in the organisation.

How to Configure Cisco Router as DNS Server