Category Archives: NETWORKING

Unknown Ipv6 and IPv4 multicast floods blocking in Mikrotik

I was troubleshooting an enterprise network for slowness the speed. So when I went through the troubleshooting steps I found that there is an IPv6 and IPv4 unknown unicast flooding that occurs in the Lan interface. it’s a medium enterprise where they have almost 400 end hosts including telephone and IP cameras as well. find the picture given… Read More »

Bandwidth Limiting / Shaping on Cisco Switch or Router Port.

When Internet Service Providers (ISP) gives a new internet link , very often they have shaping rules on their router to regulate internet traffic at promised rate. If your firewall/router/switch is sending more excessive traffic than promised rate, the packet will be dropped by ISP router, then ends up with suboptimal performance and slow internet speed. in this… Read More »

Cisco 2960 Switch Series: Rate limit Configuration on the Switch Port.

In the Cisco IOS on a Catalyst switch (not on a router), there’s an Interface Mode command called shape round-robin queue bandwidth. More specifically, the command is srr-queue bandwidth. This command has been around since IOS 12.2(25). For these examples, I’m using a Cisco Catalyst 2960 switch. Entering the command appended with a question mark will display the command options. Here’s… Read More »

IPv6 Deployement and Subnetting.

Suppose there is IP version 6 address 2001:1D11:220A::/48 assigned to an ISP with 16-bit subnet ID. The network administrators can subnet the IP version 6 address just counting /16-bit subnet ID in hexadecimal. This would allow the administrator to create 65,536 /64 subnet. The table below illustrates the subnetting procedure of IPv6 address. IPv6 Range. 2001:1D11:220A:0000::/48 2001:1D11:220A:0001::/48 2001:1D11:220A:0002::/48 2001:1D11:220A:0003::/48… Read More »

IPv6 SUbnetting.

In IPv4, the subnet mask 255.255.255.0 is 32 bits and consists of four 8-bit octets. The address: 10.10.10.0 subnet mask 255.255.255.0 means that the subnet is a range of IP addresses from 10.10.10.0 – 10.10.10.255. The prefix-length in IPv6 is the equivalent of the subnet mask in IPv4. However, rather than being expressed in four octets like it is in IPv4, it is expressed as… Read More »

How to Shorten IPv6 Addresses.

An IPv6 address consists of 32 hexadecimal digits, in 8 sections of 4 digits each, separated by colons. It looks something like this: 1234:5678:90ab:cdef:1234:5678:90ab:cdef IPv6 addresses have several shortcuts that allow them to be compressed into smaller strings following certain rules. If there are any leading zeroes in a section, they may be left off. 0001:0001:0001:0001:0001:0001:0001:0001 could be written as 1:1:1:1:1:1:1:1. Any… Read More »