Network Engineering

FEBRUARY 2, 2025

I only know a few terms (and not all of them): IPv4, IPv6, DNS, DPI but I dont actually understand what they mean. I want to understand computer networks. Where should I start? Im completely lost. Can I ask questions like this here? If you answer, Ill be very grateful!"

Networking 130

Networking Network DNS 130

Cloudera Blog

FEBRUARY 12, 2024

In Cloudera deployments on public cloud, one of the key configuration elements is the DNS. If the DNS is set up less ideal than it could be, connectivity and performance issues may arise. In this blog, we’ll take you through our tried and tested best practices for setting up your DNS for use with Cloudera on Azure.

DNS 52

DNS IP Address Server Firewall 52

Packet Pushers

OCTOBER 15, 2020

DNS Flag Day is a community effort by service providers and DNS software vendors to address DNS issues. In this week's IPv6 Buzz episode, Ed and Scott speak with guest Andrew Wertkin about the DNS flag day for 2020, which took place October 1st.

DNS 52

DNS 52

CATO Networks

NOVEMBER 2, 2021

In the past several years, we have seen multiple malware samples using DNS tunneling to exfiltrate data. BazarCall can lead to Anchor malware that uses DNS tunneling to communicate with C2 servers. APT groups also used DNS tunneling in a malware campaign to target government organizations in the Middle East.

DNS 52

DNS Networking Network Server 52

Packet Pushers

JULY 15, 2022

DNS is our subject on today's Heavy Networking. More specifically, DNS transport over TCP. We talk with John Kristoff, one of the forces behind RFC9210, which covers the operational requirements for DNS transport over TCP. This is not an esoteric document covering a tiny, nuanced DNS use case.

DNS 52

DNS TCP Networking Network 52

Obkio

DECEMBER 20, 2023

Master DNS issues with this comprehensive guide! Identify issues, optimize DNS performance & elevate your skills. Explore Obkio for advanced DNS monitoring.

DNS 52

DNS 52

Packet Pushers

SEPTEMBER 20, 2018

Today's IPv6 Buzz podcast dives into the critical relationship between IPv6 and DNS with guest Cricket Liu, author and Senior Fellow at Infoblox. We drill into DNS64 and DNSSEC, and look into DNS's future. We drill into DNS64 and DNSSEC, and look into DNS's future.

DNS 52

DNS 52

Packet Pushers

NOVEMBER 12, 2021

The DNS Abuse Institute is a community effort to develop solutions to DNS-related problems including malware, botnets, phishing, pharming, and spam. On today's show we speak with its Director, Graeme Bunton, about the institute and its work, and the challenges of dealing with malicious actors that exploit DNS and domain names.

DNS 52

DNS Networking Network 52

Packet Pushers

APRIL 21, 2023

In this episode, Ed, Scott, and Tom discusshow hosts OSes such as Windows, Apple, and Android automatically obtain both IPv6 addressesand DNS server information. In this episode, Ed, Scott, and Tom discusshow hosts OSes such as Windows, Apple, and Android automatically obtain both IPv6 addressesand DNS server information.

DNS 52

DNS Server 52

Packet Pushers

APRIL 7, 2023

Lots of them run apps that discover services on your network via multicast DNS (mDNS). Lots of them run apps that discover services on your network via multicast DNS (mDNS). You know all those Apple and other IoT devices connected to your wireless network?

DNS 52

DNS Wireless Networking Network 52

ByteByteGo

FEBRUARY 1, 2025

18 Common Ports Worth Knowing FTP (File Transfer Protocol): Uses TCP Port 21 SSH (Secure Sheel for Login): Uses TCP Port 22 Telnet: Uses TCP Port 23 for remote login SMTP (Simple Mail Transfer Protocol): Uses TCP Port 25 DNS: Uses UDP or TCP on Port 53 for DNS queries DHCP Server: Uses UDP Port 67 DHCTP Client: Uses UDP Port 68 HTTP (Hypertext Transfer (..)

UDP port 251

UDP port TCP Port Protocol 251

Kentik

AUGUST 21, 2017

Dashboards for DNS Metrics Reveal Issues With Your Infrastructure. Working behind the scenes, Domain Name Server (DNS) is often overlooked, but it’s one of the most critical pieces of the Internet infrastructure. That point was driven home by the Mirai DDoS attack last October against the DNS infrastructure of Dyn, Inc.

DNS 40

DNS Server IP Address Ethernet 40

Obkio

APRIL 10, 2024

Learn how the hostname of a traceroute hops can provide information about the real path from the source to the destination. Try Obkios Live Traceroute now!

DNS 52

DNS 52

ByteByteGo

JANUARY 11, 2025

DNS lookup begins (think of it as looking up a phone number). The request goes through different DNS servers (root, TLD, and authoritative). First up, you type the website address in the browser’s address bar. The browser checks its cache first. If there’s a cache miss, it must find the IP address.

IP Address 201

IP Address Server TCP DNS 201

Network Engineering

AUGUST 19, 2020

dns-server 10.0.0.2 dns-server 10.0.0.2 dns-server 10.0.0.2 dns-server 10.0.0.2 ! ! ip dhcp pool mgmt network 10.0.0.0 255.255.255.0 default-router 10.0.0.1 domain-name LAN ip dhcp pool trusted network 10.0.10.0 255.255.255.0 default-router 10.0.10.1 ip dhcp pool untrusted network 10.0.20.0 255.255.255.0 255.255.255.0

IP Address 130

IP Address DNS Routers Server 130

InfoQ Articles

OCTOBER 11, 2024

By implementing batch compression and switching to DNS-based discovery, Netflix optimizes efficiency, reduces bandwidth usage and significantly lowers operational costs. This infrastructure ensures global availability and resilience through intelligent data routing and flexible replication strategies.

DNS 111

DNS Bandwidth Server Cloud 111

Kentik

JANUARY 24, 2022

Lots of applications use these ports today, including DNS lookups and email. Some of the IP addresses these services use will reverse DNS resolve to a hostname that gives away the application; however, a huge portion will not. NetFlow application monitoring: Use DNS logs. How did this happen? NetFlow with NBAR.

Application 96

Application IP Address DNS Port 96

Kentik

SEPTEMBER 22, 2021

Kentik’s OTT Service Tracking (part of Kentik Service Provider Analytics) combines DNS queries with NetFlow to allow a user to understand exactly how OTT services are being delivered - an invaluable capability when trying to determine what is responsible for the latest traffic surge. OTT Service Tracking.

DNS 145

DNS Port Routers Networking 145

Kentik

OCTOBER 6, 2017

And Google disclosed seven vulnerabilities in DNS’ Dnsmasq software. Yet More DNS and DHCP Vulnerabilities (Google Blog). Most Companies Are Unprepared for DNS Attacks (HelpNetSecurity). Russia also made headlines for its covert efforts to steal secrets from the NSA.

DNS 40

DNS Internet Networking Network 40

Kentik

OCTOBER 12, 2021

Some NPM vendors started pairing DNS lookup records with flow data in order to separate business applications from non-business applications hosted on the same IP address. The problem is that many companies have several DNS servers spread out in far-reaching locations, and not all DNS vendors allow access to the logs.

Encryption 84

Encryption DNS IP Address Protocol 84

Network Engineering

JANUARY 30, 2025

doesn't work as well as nslookup, and currently when I use wireshark it shows strings of attempting to make DNS queries to 8.8.8.8 Every interface can be pinged without issue, and the Kali machine also connects to the internet just fine; my main frustration at this point is why I can't seem to connect the Debian side to the internet.

Internet 130

Internet LAN Virtual machine Gateway 130

Network Engineering

JANUARY 4, 2025

From a networking point of view, DNS is functional and there are no firewall entries that can restrict the traffic. Has anyone got a list of FQDN's and IP's that should be whitelisted for Samsung Pay?

Firewall 130

Firewall DNS Gateway Routers 130

Network Engineering

OCTOBER 7, 2015

24)T8 Cleansed config pasted below: crypto isakmp policy 10 encr aes authentication pre-share group 2 crypto isakmp key address no-xauth crypto isakmp keepalive 20 3 crypto isakmp client configuration group ABC key dns domain pool ABCpool acl 150 max-logins 10 netmask 255.255.255.0 Running C3825-ADVIPSERVICESK9-M Version 12.4(24)T8

VPN 130

VPN Port Routers Server 130

Kentik

JANUARY 10, 2022

Domain lookup time : When a connection is made to a domain, the local operating system must first reach out to the DNS to resolve that hostname to an IP address. Where is the DNS? Is your PC using a DNS on the same local area network as your computer? The HTML, the CSS, etc. all have to be downloaded.

IP Address 98

IP Address DNS TCP Application 98

Network Engineering

JULY 3, 2021

threat-detection basic-threat threat-detection statistics access-list no threat-detection statistics tcp-intercept webvpn username cisco password 3USUcOPFUiMCO4Jk encrypted ! class-map inspection_default match default-inspection-traffic ! !

VPN 130

VPN IP Address Encryption TCP 130

Kentik

OCTOBER 4, 2021

Included in the withdrawn prefixes were the IP addresses of Facebook’s authoritative DNS servers, rendering them unreachable. During the outage, the TCP traffic went away entirely, leaving a small amount of UDP traffic consisting of DNS retries from Facebook’s 3.5 billion users attempting in vain to reconnect to their services.

TCP 145

TCP DNS Server Media 145

AWS Architecture

NOVEMBER 11, 2024

It is specifically focused on managing DNS routing and traffic management during failover and recovery operation; however, some customers decide to implement their own strategies for application recovery. As explained in the failover section, the DNS switchover depends on a file existing in S3.

Insurance 122

Insurance Application DNS Server 122

DoorDash Engineering

AUGUST 15, 2023

For example, our DNS probe has an event with just the network namespace id (netns), process id (pid), and the raw packet data. pkg: github.com/doordash/bpfagent/pkg/tracing/dns cpu: Intel(R) Core(TM) i9-8950HK CPU @ 2.90GHz BenchmarkEventUnmarshal-12 8289015 127.0 rdr, err := ringbuf.NewReader(p.objs.Events) //.

DNS 84

DNS TCP Application Networking 84

Kentik

JANUARY 28, 2021

DNS query streams are also a very useful type of network telemetry, whether observed from the DNS service logs, or from the network traffic on the hosts running DNS servers. In addition, DNS telemetry can be helpful to put traffic and other telemetry types in context. What is my DNS request load for my servers?

Networking 72

Networking Network DNS IP Address 72

Kentik

NOVEMBER 17, 2021

Kentik’s OTT Service Tracking (part of Kentik Service Provider Analytics) combines DNS queries with NetFlow to allow a user to understand exactly how OTT services are being delivered — an invaluable capability when trying to determine what is responsible for the latest traffic surge. OTT Service Tracking.

DNS 99

DNS Port Routers Networking 99

ByteByteGo

DECEMBER 7, 2024

Used in DNS querying and CDNs. Anycast Sender to a single device or a specific group of devices. For example, saying thank you to one host out of a group of hosts organizing a party. All other hosts also expected to receive the thank you note. Over to you: Which approach have you used? How Does VISA Make Money?

Unicast 211

Unicast Banking Protocol Networking 211

Packet Pushers

JUNE 13, 2024

If you dont blame destination unreachable messages on DNS servers, are you even a real network engineer? Read more » If you dont blame destination unreachable messages on DNS servers, are you even a real network engineer? He walks us through identifying possible. He walks us through identifying possible. Read more »

DNS 52

DNS Networking Network Server 52

Kentik

DECEMBER 13, 2021

This is sort of a long shot, but are you using a corporate DNS server? You might try temporarily switching to a public DNS like Google’s 8.8.8.8. DNS lookups can introduce significant latency on new connections. Shut them down and try working with my SaaS application after making some or all of the above changes.

Application 95

Application DNS Routers Server 95

High Scalability

AUGUST 22, 2018

In the early days of the internet the internet was protocol driven, decentralized, and often distributed—FTP (1971), Telnet (<1973), FINGER (1971/1977), TCP/IP (1974), UUCP (late 1970s) NNTP (1986), DNS (1983), SMTP (1982), IRC(1988), HTTP(1990), Tor (mid-1990s), Napster(1999), and XMPP(1999).

TCP 88

TCP Internet DNS Protocol 88

Kentik

JANUARY 7, 2020

Customers use our inbound APIs to send us various types of data, including threat feeds, DNS data, scoring data, or even physical topology data. Automatic DNS resolution option for IP addresses in Grafana. Since then, we’ve been busy building new enhancements and features, along with documentation of how to install the new plugin.

DNS 16

DNS IP Address Topology DevOps 16

Packet Pushers

OCTOBER 12, 2021

This week on Network Break, VMware disgorges a slew of announcements at VMworld 2021, Facebook shoots itself in the foot with BGP and DNS bullets, Marvell announces new silicon for Data Processing Units (DPUs), and more tech news analysis.

DNS 52

DNS Networking Network 52

Confluent

OCTOBER 7, 2019

Especially note the exposing external endpoints and proper DNS setup explained in part 1. External endpoint exposure with public DNS is required for this tutorial. Here’s a screenshot of my DNS setup for the domain name used in part 1. Running and accessible Confluent Schema Registry , which was mentioned in part 1, in PKS.

Application 18

Application DNS PaaS Server 18