Kentik

NOVEMBER 7, 2021

The mail server, the CRM, the file servers, etc. If we had a connection problem, we’d call over the cubical something like, “Hey Darla, can you see the Skywalker server? The NetOps team can’t Telnet to routers and look at routing tables, and they can’t change routes or span a port to collect packets.

Routers 104

Routers Internet Application Server 104

Network Engineering

OCTOBER 7, 2015

We have a Cisco 3825 router with an IPSec Remote Access VPN configured to authenticate against a radius server. We're retiring the old server and moving to a new one (Windows Server 2012). We changed the radius-server host line in our config accordingly and the router is able to communicate with the new radius server.

VPN 52

VPN Port Routers Server 52

The Network DNA

NOVEMBER 26, 2024

NDNA-ASA(config-if)# nameif dmz NDNA-ASA(config-if)# security-level 70 NDNA-ASA(config-if)# no shut Configure static NAT to the DMZ server using a network object NDNA-ASA(config)# object network dmz-server NDNA-ASA(config-network-object)# host 10.10.2.3 10.10.10.100 inside NDNA-ASA(config)# dhcpd dns 112.110.112.5 255.255.255.0

Firewall 52

Firewall IP Address VPN Port 52

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. In some cases, network scanners will use port scans and in other cases ping sweeps. As for SQL Servers, it seems like the hunt for databases still exists.

Network 52

Network Networking Server Port 52

The Network DNA

NOVEMBER 26, 2024

NDNA-ASA(config)# http server enable NDNA-ASA(config)# http 10.10.10.0 Configure the ASA to allow HTTPS connections from any host on the inside network (10.10.10.0/24). 255.255.255.0 inside Continue Reading.

Firewall 52

Firewall VPN IP Address Port 52

Kentik

JANUARY 13, 2021

Ping is a utility that’s available on practically every system, be it a desktop, server, router, or switch. Both packets and flows provide information about the source and destination IPs, ports, and protocols. If it’s unclear from flow, and often if it’s a router or other system bug, you may need to go to the packets.

Network 114

Network Networking TCP Protocol 114

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

APRIL 3, 2023

Higher level abstractions For another level of abstraction, open source tools have emerged, such as Cilium , which runs as an agent in container pods or on servers. 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

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. Juniper MX and PTX series routers (via IPFIX).

Routers 40

Routers IP Address Protocol Server 40

Kentik

DECEMBER 22, 2016

Kentik’s NPM solution goes beyond typical NetFlow traffic analysis in that it is enabled through the installation of an nProbe application on Linux based servers. Well, as the probe is installed on the server itself, it is privy to information which NetFlow devices are not. Network latency per client/server/application (ms).

Network 40

Network Networking Server Port 40

Kentik

SEPTEMBER 26, 2016

In those settings, you might drop NPM appliances into major data centers, perhaps directly connected to router or switch span ports, or via a tap or packet broker from the likes of a Gigamon or Ixia. routers and switches). Kentik’s server-side NPM instrumentation goes wherever the servers go, in the data center or in the cloud.

Network 40

Network Networking Data Centers Server 40

Kentik

NOVEMBER 18, 2016

Kentik offers a cloud-friendly NPM solution that includes the mature and proven nProbe NPM agent from ntop that can be installed on application and load balancing servers. Kentik Detect also takes in flow, BGP, SNMP and other data at scale from routers, switches, probes.

Cloud 40

Cloud Server Port DevOps 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

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

SEPTEMBER 20, 2016

For example, using SNMP or flow data to track traffic volume on interfaces, servers, and devices can provide necessary visibility into possible congestion points. As an example, we’ll use traffic from Kentik’s own servers. We were also observing slow response times from applications running on the server. TCP is the key.

Network 40

Network Networking TCP 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. Top L4 Ports. The key to making that work is Kentik’s Data Explorer API.

Port 40

Port Email Network Networking 40

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. UDP vs. TCP. TTL expired.

Cloud 116

Cloud TCP Routers Protocol 116

Kentik

MAY 17, 2021

And it’s not like the network teams had to worry about fixing failed line cards or erroring ports. 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. So we asked hundreds of questions to try and understand what was going on.

Cloud 52

Cloud Network Networking Gateway 52