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Posts published in “Computer & Internet”

How to init connection with a Cisco over serial & minicom?

Trying to connect to a Cisco router, in purpose to learn Cisco skills that could help me finding a job. So, I plugged a cable in the rj45 Console (blue) port of a Cisco 888 router, and other end into serial port. On Debian 10, I installed ...

iperf3 UDP tuning

I am trying to test throughput in the network. But when i start iperf3 client for sending UDP packets it sends TCP SYN packets. Why does it behave like this? (it should not send udp tcp syn while connectiing to UDP server)

Unable to ping but I can see the arp in switch 4451

Recently I got to know that I am unable to ping the IP addresses behind vlan236 from core1 whereas I am able to ping the same from core2 and able to ping the IP address of vlan236 from my laptop as well.
I can see the arp entry as well but...

%Cannot create sub-interface

I'm trying to connect 4 networks with 1 router, i created 2 sub-interfaces in the router, when i tried to create the 3rd sub-interface i got this output "%Cannot create sub-interface", this is my topology:

Router and switches routing protocol configuration

If I connect switches in each building together, which also link a router, does a routing protocols need to be configured on the switches and the router, or just the router?

tcpdump find source ip with most bytes

some times we receive volumetric traffic from single source IP (out of our networks) towards one destination in our network,
is there anyway to find it with tcp dump ?
thank you.

Why is an IPv6 interface required to have a link-local address?

According to Link-local address on Wikipedia:

In IPv4, link-local addresses are normally only used when no external, stateful mechanism of address configuration exists, such as the Dynamic Host Configuration Protocol (DHCP), or when anoth...