DoorDash Engineering

NOVEMBER 29, 2022

As discussed in the previous section, our forward-looking payment processing vendors deployed their servers in on-premise data centers, instead of the cloud, to ensure that they have total control over data storage and transfer. Vendor’s data centers have private links to their own routers which are set up in AWS Direct Connect Locations.

Data Centers 97

Data Centers Cloud Gateway IP Address 97

Kentik

JANUARY 10, 2022

To be more specific: slowness can be introduced as your digital connection traverses your PC, the local wifi/wired connection, the local ISP, the Tier 1 or Tier 2 provider, or the CDN that provides the hardware which hosts the web server running the application. Your PC sends out what is called a “SYN” packet to the destination’s IP address.

IP Address 98

IP Address DNS TCP Application 98

Network Engineering

AUGUST 19, 2020

The problem is that when ESXi is down it takes down all the network with it, so I have to boot up another router to log in to it. WAN > OPNsense (in ESXi)> switch (C3560G) OPNsense is DHCP server Thing is that i would like the switch to deal with the DHCP, to avoid being naked when ESXi needs maintenance. default-router 10.0.0.1

IP Address 52

IP Address DNS Routers Server 52

Kentik

DECEMBER 13, 2021

To properly monitor them, it’s paramount to find out which servers your end users are connecting to. This is sort of a long shot, but are you using a corporate DNS server? Notice above that the routers used in the connection are looking pretty snappy. Make sure that both devices are using the same server.

Application 95

Application DNS Routers Server 95

Kentik

AUGUST 3, 2021

When the network team investigates, they may see all types of problems such as ingress and egress points with no security policies, internal communications routed over internet gateways, abandoned gateways, abandoned subnets with overlapping IP address space, or VPC peering connections with asymmetric routing policies.

Cloud 124

Cloud Network Networking Gateway 124

Kentik

FEBRUARY 8, 2023

Port mirroring Another method for gathering traffic telemetry is port mirroring, which replicates (mirrors) the network traffic on a switch or router to a monitoring device. Software probes Software probes are programs that can be installed on servers or network devices to collect data on network traffic.

Network 111

Network Networking Port IP Address 111

The Network DNA

NOVEMBER 26, 2024

Cisco ASA in a Network Configuring DHCP, AAA, and SSH NDNA-ASA(config)# dhcpd address 10.10.10.3-10.10.10.100 NDNA-ASA(config)# dhcpd option 3 ip 10.10.10.1 Configure address translation using PAT and network objects NDNA-ASA(config)# object network INSIDE-NET NDNA-ASA(config-network-object)# subnet 10.10.10.0 255.255.255.0

Firewall 52

Firewall IP Address VPN Port 52

Kentik

OCTOBER 12, 2021

Once you saw a person’s password to any given application, you knew they were generally using the same one for all of their other applications — email, the ticketing system, the FTP and Novell servers, etc. Increased HTTPS traffic made it difficult for routers to provide insights beyond traditional NetFlow v5 metrics.

Encryption 84

Encryption DNS IP Address Protocol 84

The Network DNA

NOVEMBER 26, 2024

NDNA-ASA(config)# interface gi1/2 NDNA-ASA(config-if)# nameif inside NDNA-ASA(config-if)# ip address 10.10.10.1 NDNA-ASA(config-if)# ip address 112.23.16.11 NDNA-ASA(config)# http server enable NDNA-ASA(config)# http 10.10.10.0 255.255.255.0 255.255.255.0 inside Continue Reading.

Firewall 52

Firewall VPN IP Address Port 52

Kentik

SEPTEMBER 19, 2018

In a nutshell, UE enriches all the flow data Kentik receives with tags that indicate the PoP, router, interface, etc. Each network device (switch, router) in this network is sending data to Kentik (flow, BGP, and SNMP data). Based upon the flow generated from the border router, we can see that this flow is originating from 1.1.1.1

Network 49

Network Networking Routers Server 49

CATO Networks

JANUARY 17, 2018

In the light of recent ransomware attack campaigns against Microsoft RDP servers, Cato Research assessed the risk network scanning poses to organizations. As for SQL Servers, it seems like the hunt for databases still exists. Although well researched, many organizations continue to be exposed to this attack technique.

Network 52

Network Networking Server Port 52

Kentik

AUGUST 14, 2017

We know that flows are a set of packets that share common attributes including protocol, source and destination IP, and src, dst, and next-hop AS. are generated by individual routers, switches, and hosts rather than system wide. This could be a backbone interface, or an interface towards a server inside the network.

IP Address 40

IP Address Routers Network Networking 40

Kentik

JULY 20, 2018

Once NetFlow is enabled on a router or other network device, it tracks unidirectional statistics for each unique IP traffic flow, without storing any of the payload data carried in that session. In these cases, collectors then synchronize their data to a centralized analyzer server. Alcatel-Lucent routers. Linux devices.

Routers 40

Routers IP Address Protocol Server 40

Kentik

APRIL 3, 2023

You can modify the program to capture other information as well, such as the number of retransmit attempts or the source and destination IP addresses of the affected packets. Second, in a busy network, devices such as routers, switches, and firewalls may be very busy operating at a relatively high CPU.

TCP 110

TCP Application Virtual machine Network 110

Kentik

OCTOBER 20, 2021

We can’t telnet to the routers in the path because different companies in different countries own them. Using BGP, public IP addresses can be associated with a business’s Autonomous System, but this doesn’t always reveal the actual application (e.g., How then can we gain visibility into why a connection is slow for a given user?

Encryption 52

Encryption Routers DevOps Application 52

Kentik

JUNE 30, 2015

We were one of SprintLink’s first BGP customers, and we had dozens of Cisco and Wellfleet routers. Who’s transferring data with our servers that shouldn’t be? Were our servers talking to each other on weird ports? And we had hundreds of “big” Cisco routers that were capable of generating Cisco’s new NetFlow network data.

Routers 40

Routers Port Server Network 40

Kentik

DECEMBER 1, 2016

An operator would then log into a route server and configure the mitigation, which is a /32 host “black hole” route. The route is then redistributed via BGP — along with a ‘no-export’ community and a next-hop address — to the routers where the attack traffic is entering the network. I think I’m under attack.”

Routers 40

Routers Network Networking IP Address 40

Kentik

APRIL 24, 2017

For example, with a forged source-address DDoS attack, every packet can be a flow, and routers have to try to maintain massive tables on the fly to track those flows! sFlow, on the other hand, is based on interface counters and flow samples created by the network management software of each router or switch.

Protocol 40

Protocol Routers Bandwidth Internet 40

Kentik

DECEMBER 2, 2015

The issue was a new type of “spam reflection” that was causing headaches by allowing spammers to avoid detection while utilizing servers inside the customer’s network as spam sources. Here’s how these types of schemes work: The spammer sends a SYN from a spoofed source IP address to TCP port 25 (SMTP) on the target mail server.

TCP 40

TCP Protocol Port IP Address 40

Kentik

MARCH 6, 2017

One key point, as revealed in Akamai’s Q3 2016 State of the Internet Security Report, is that the vast majority of DDoS attacks — over 98% — are focused on disrupting access to network or server infrastructure rather than on targeting application limitations or vulnerabilities.

IoT 40

IoT DNS IP Address Server 40

Kentik

MAY 16, 2016

Note that what follows here is not intended as an HTML or PHP programming guide; the reader is expected to understand Web server security, API authentication, and customer portal development. Test directory : Create a new folder on the Web server (e.g. The key to making that work is Kentik’s Data Explorer API.

Port 40

Port Email Network Networking 40

Kentik

JULY 11, 2017

The library includes templates for alerting on DDoS attacks, changes in top talker IP addresses, changes in geography, interfaces approaching capacity, devices that stop sending flow, and much more. Kentik is continually adding to the library as we add new features and uncover new use cases. Dimensions, metrics, and filters.

Email 40

Email Network Networking IP Address 40

Kentik

JUNE 5, 2023

A mis-origination occurs when an AS originates (announces with its ASN as the origin) a new advertisement of a route to an IP address block over which it does not possess legitimate control, consequently soliciting traffic destined to those IP addresses.

IP Address 145

IP Address DNS Internet Routers 145

Kentik

JULY 28, 2021

Bad hardware (the switch or router port). Overwhelmed router. Congestion in the form of high-connection utilization or an overworked router in the path is another common source of trouble. TCP traceroute : A TCP trace reaches out to every router in the path to a target destination. Miss-matched duplexing (full vs. half).

Cloud 116

Cloud TCP Routers Protocol 116

Kentik

MAY 17, 2021

Fifteen years ago you couldn’t launch a new business or even run a school without having a server, a switch, and a router sitting in a rack somewhere. Consider the edge components of an on-prem network: the expensive routers, switches, and firewalls. to the raw source and destination IP addresses in your VPCs.

Cloud 52

Cloud Network Networking Gateway 52

Network Engineering

JANUARY 31, 2025

After a juniper router upgrade we started having MTU problems. I'm no longer able to send the router a 1500 byte ICMP packet (on a direct attached subnet with vlan) and get a reply. If I adjust the MTU in my linux server to 1504, I do get a reply but with an extra 4 bytes.

Routers 52

Routers IP Address Server Network 52