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VTP: VLAN is not propagating

This Topology is simple but my VLAN is not propaganting. I'm following this Tutorial

Multilayer Switch0

VTP Version : 2
Configuration Revision : 2
Maximum VLANs supported locally : 1005

Do different nodes on a LAN share a public IPv6 address?

I looked up the public IPv6 addresses on google for two devices on my LAN, and the addresses are unique (only the first 64 bits match).

I thought that the router connected to the internet has a public IPv6 address that is ...

incorrect subnet mask for route summarization

I am learning about route summarization and how it represent different subnets with a single address and single subnet mask,

for example,

if i have two subnets,

The summarized subnet with subnet mask ...

Why Can’t I Subnet the First Octet?

Why is it possible for me to create a network such as which ranges from to but not a network such as which should range from to

For some reason I am u...

Reason for excessive amount of collisions in hub networks?

I ran a test-setup which caused excessive amount of collisions on Cisco FastHub 400 port. This caused switch to isolate this port. For example in case of port 6, this has happened 766 times:

Hub#sh interfaces fastethernet 1/...

ARP table is not updated with NMAP

Here is what I do and what happens :

Let assume I have a device A with IP X.X.X.200 connected to the network
I use Nmap to ping my local network, with the command "nmap --send-ip -sP"
Look at the arp table us...

HSRP causing switch CAM entries to expire

I have host which is connected to a switch. I need to establish a communication with a server which is not in my network. So I am using two routers(gateways) ,configured with HSRP, between my host and the server.

When I send a ARP request...