Kentik

SEPTEMBER 20, 2021

Not as difficult as time travel, but it’s difficult enough so that for 30+ years IT professionals have tried to skirt the issue by adding more bandwidth between locations or by rolling out faster routers and switches. Each switch and router we pass through introduces a bit of latency that adds up quickly. How latency is measured.

TCP 116

TCP Routers Bandwidth IP Address 116

Kentik

JANUARY 6, 2021

The critical context that enables teams to ask questions about users, applications, and customers (and not just IP addresses and ports). Traditional WAN : WAN access switches, integrated services routers, cloud access routers. The key telemetry types to shine a light on network activity and health.

Networking 128

Networking Network Gateway Access Point 128

Network Engineering

JANUARY 14, 2025

If I assign a static IP on the device level that is within the DHCP range of the network it's on, but don't reserve its address on the DHCP server, will the device lose its IP address or be disconnected if the router restarts?

IP Address 52

IP Address Routers Server Networking 52

Network Engineering

MAY 5, 2023

I have this network when the network tries to communicate with the routers it fails. Router>enable Router# Router#configure terminal Enter configuration commands, one per line. Router>enable Router# Router#configure terminal Enter configuration commands, one per line. End with CNTL/Z.

IP Address 52

IP Address Routers Protocol Networking 52

Kentik

OCTOBER 4, 2021

According to a statement published last night, Facebook Engineering wrote, “Configuration changes on the backbone routers that coordinate network traffic between our data centers caused issues that interrupted this communication.” tfbnw.net — which is another router inside AS32934 that belongs to Facebook. So what happened?

TCP 145

TCP DNS Server Media 145

Network Engineering

FEBRUARY 2, 2024

set system mode router ! vlan database vlan 10,20 exit interface vlan 1 ip address 101.205.25.252 255.255.255.0 no ip address dhcp ! interface vlan 10 ip address 101.205.10.1 interface vlan 20 ip address 101.205.20.1 255.255.255.0 ! 255.255.255.0 !

IP Address 52

IP Address Port Routers 52

Kentik

JANUARY 10, 2022

Or, perhaps one or more of the 10-20 routers in the path needed to reach the destination gets busy for a hundred milliseconds or so. 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?

IP Address 98

IP Address DNS TCP Application 98

The Network DNA

JULY 5, 2024

Route type 2, or the advertisement route for MAC/IP: This broadcasts the MAC and IP addresses of the endpoints, or VTEPs, as well as endpoint reachability data. Ethernet segment routes, or route type 4, are used to broadcast the length of the IP address, the originating router's IP address, and the Ethernet segment identifier.

IP Address 52

IP Address Ethernet Advertising Unicast 52

The Network DNA

JULY 9, 2024

Replacing cEdge in Cisco SDWAN environment Replacing the cEdge router with another cEdge through an RMA process for Cisco SDWAN , we need to put the basic configuration on the new RMA router and should be reachable via vManage. It is important that you should know the new router serial number should be learned to vManage NMS.

Routers 52

Routers IP Address MPLS WAN 52

NW Kings

JANUARY 7, 2025

In this blog, we will explore what static routes are, how they differ from dynamic routes, and how to configure them on routers like Cisco devices. This characteristic makes them efficient for routers with limited processing capabilities. What are the key features of static routes? How can I configure static routes?

Routers 52

Routers IP Address Protocol Topology 52

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. ip dhcp pool mgmt network 10.0.0.0 default-router 10.0.0.1 domain-name LAN ip dhcp pool trusted network 10.0.10.0 default-router 10.0.10.1 ip dhcp pool untrusted network 10.0.20.0

IP Address 52

IP Address DNS Routers Server 52

Kentik

MAY 21, 2019

The Mirai botnet was first discovered back in 2016, but has continued to persist and abuse common vulnerabilities and exposures (CVEs) on IoT devices, including home routers and many other network-connected devices. These addresses were apparently port scanning IP addresses that belonged to the company sending the letter.

Port 81

Port IP Address Internet Networking 81

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. SRX has the MTU of the physical interface set to 2000 but the irb interface with the ip address I'm pinging set to 1500.

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52

Network Engineering

JULY 19, 2021

I would really appreciate ISP Int g0/0 ip add 2.2.1.1 255.255.255.252 no shut Int g0/1 IP add 2.2.2.1 255.255.255.252 no shut int g0/2 ip add 2.2.3.1 255.255.255.252 no shut int g0/3 ip add 4.4.129.1 255.255.255.252 no shut int g0/3 ip add 4.4.128.1 interface G0/0 nameif outside security-level 0 ip address 2.2.1.2

IP Address 52

IP Address Encryption Routers Networking 52

CloudFaire

JANUARY 3, 2025

As a result, Internet devices usually use a single path and let the routers handle the path selection. The in-kernel path manager requires some configuration it must know which IP addresses and interfaces are okay to start new subflows. This is configured with ip mptcp endpoint. There is another way.

TCP 137

TCP Port Server Advertising 137

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 Networking Network Gateway 124

Kentik

SEPTEMBER 10, 2021

If the response comes back like the above, I’ll probably reboot my computer, my internet router or maybe both and hope that this fixes the problem. And which router or autonomous system introduced the latency? In the picture above, by mousing over the little green circles at the bottom, the IP address of the hops are listed.

Application 113

Application Cloud Routers IP Address 113

Kentik

MAY 8, 2023

TCP/IP is one of the fundamental networking protocols and the basis for common protocols like HTTP. IP address abstraction and failover capabilities with DNS Domain Name System (DNS) is a system for mapping domain names to IP addresses.

Networking 52

Networking Network IP Address TCP 52

Network Engineering

APRIL 7, 2022

Looking for some help setting up a Dell PowerConnect 2724. 1st time setting one of these up.

Port 52

Port IP Address Routers 52

Kentik

DECEMBER 13, 2021

Notice above that the routers used in the connection are looking pretty snappy. If you “ain’t afraid of getting dirty,” use the Wireshark packet analyzer to see if your connection to the SaaS applications’ IP address is suffering from any packet loss. DNS lookups can introduce significant latency on new connections.

Application 95

Application DNS Routers Server 95

DoorDash Engineering

JANUARY 16, 2024

Internal Envoy routers allow communication between the global cell and replicated cells. Clients leverage DNS names to dynamically discover all pod IP addresses of desired services. The EDS resource includes pod IP addresses and their AZ information.

Cloud 84

Cloud IP Address DNS Routers 84

Network Engineering

JANUARY 25, 2025

the devices connected to LAN 1 have an IP adress of (192.168.0.x), x), and the devices connected to LAN 2 have IP address in the form of (192.168.1.x). we have 2 different LANs, a printer and some PCs are connected to LAN 1 via an ethernet cable, and some PCs are connected to LAN 2, also via an ethernet cable.

LAN 52

LAN Ethernet IP Address Routers 52

Kentik

MARCH 13, 2019

A common DDoS mitigation technique is Remotely-Triggered Black Hole (RTBH), which requires extensive pre-configuration of discard routes and/or uRPF on all edge routers. For destination-based RTBH, the victim’s destination IP address becomes completely unreachable. The mitigation actually “completes the attack.” Action Type.

IP Address 49

IP Address Port Routers DNS 49

CATO Networks

FEBRUARY 22, 2022

MPLS (Multiprotocol Label Switching) is a network routing technique that is based on predetermined paths, instead of routers determining the next hop in real-time. This enables quicker and more efficient routing, as the router only needs to view a packet label, instead of looking up the address destination in complex routing tables.

MPLS 52

MPLS Routers Networking Network 52

Kentik

JUNE 7, 2023

They capture detailed information about network traffic, including: Source and destination IP addresses Ports Protocols Packet counts By analyzing these logs, you can gain visibility into the volume, patterns, and characteristics of traffic, such as whether it’s being dropped or incorrectly routed, to identify connectivity issues.

Cloud 97

Cloud Gateway Port IP Address 97

The Network DNA

MAY 24, 2024

This policy will match with the site id and we use this policy for the router in Site-1 only towards outbound direction. In order to manipulate the traffic from the DC-1 to Site-1 you need to apply the policy on DC-1 router using the data policy and import it to the Centralized policy. Continue Reading. x Free Tools.

MPLS 52

MPLS WAN IP Address Routers 52

CATO Networks

APRIL 26, 2016

There isnt going to be a shiny new router that would magically solve it all. IP Routings Historical Baggage: Simplistic Data Plane Whether the traffic is voice, video, HTTP, or email, the Internet is made of IP packets. Packets hop from router to router, only aware of their next hop and their ultimate destination.

Internet 52

Internet Routers MPLS Protocol 52

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 112.23.16.11 255.255.255.0 NDNA-ASA(config)# http server enable NDNA-ASA(config)# http 10.10.10.0 255.255.255.0 inside Continue Reading.

Firewall 52

Firewall VPN IP Address Port 52

Kentik

FEBRUARY 8, 2016

An internal routing scheme so that every router in a given AS knows how to get to every other router and destination within the same AS. One or multiple border routers. This peering connection is used by border routers in one AS to “advertise” routes to border routers in a different AS (more on this below).

Advertising 49

Advertising Routers Internet Protocol 49

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

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. Then, correlate that data with information such as IP addresses, MAC addresses, and device names.

Networking 111

Networking Network Port IP Address 111

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. Base the rule on IP, which might be stated as “if IP address is in subnet 123.456.78.90

IP Address 40

IP Address Routers Networking Network 40

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

Networking 49

Networking Network Routers Server 49

Kentik

OCTOBER 12, 2021

When companies started outsourcing the hosting of their websites to the likes of Akamai and AWS, network teams learned quickly that many work- and non-work related applications shared the same IP address. Increased HTTPS traffic made it difficult for routers to provide insights beyond traditional NetFlow v5 metrics.

Encryption 84

Encryption DNS IP Address Protocol 84

Kentik

AUGUST 1, 2016

In particular we’ve learned that speaking or advertising BGP to your service providers and/or peers lets you do two things: Make semi-intelligent routing decisions concerning the best path for a particular route to take outbound from your network (otherwise you would simply set a default route from your border routers into your service providers).

Routers 40

Routers Advertising IP Address Ethernet 40

CATO Networks

JUNE 23, 2019

The infamous malware that crippled global DNS provider Dyn, French Web host OVH and security journalist Brain Krebs Web site with botnets of infected home routers, baby monitors and other IoT devices is now infecting enterprise network equipment, according to a recent Palo Alto Networks blog and Network Computing article.

IoT 52

IoT WAN Routers IP Address 52

Kentik

APRIL 6, 2021

Instead, Transit Gateways act as cloud routers by maintaining their own routing tables and attachments. traffic from your on-prem infrastructure to public AWS S3 IP addresses or other publicly available AWS services). Analyze Your VPC Flow Logs!

Gateway 98

Gateway Cloud Networking Network 98