IPv6 Quiz – Cisco Bias

January 16, 2018 at 7:49 pm


This latest quiz is focused on IPv6 with a bias to Cisco Systems. These questions are what one could expect on a CCNP or CCIE exam across various tracks. Enjoy!

IPv6 Quiz - Cisco Bias

Congratulations - you have completed IPv6 Quiz - Cisco Bias. You scored %%SCORE%% out of %%TOTAL%%. Your performance has been rated as %%RATING%%
Your answers are highlighted below.
Shaded items are complete.

.75.1 Lab Exam Strategies; Config Section- Core vs Non-Core Tasks

January 8, 2018 at 10:15 am
You need to login to view this content. Please . Not a Member? Join Us

400-101 CCIE R&S Written – Free Resources – UDP Operations

January 6, 2018 at 11:28 am


If a TCP session is like a phone call – then a UDP transmission is like a postcard! Here are the free study resources around UDP!

1.1.f Explain UDP operations
1.1.f [i] Starvation
1.1.f [ii] Latency
1.1.f [iii] RTP/RTCP concepts

The UDP Protocol

UDP Broadcast Flooding

Defending Against Distributed DoS Attacks

IP SLA Configuration Guide



400-101 CCIE R&S Written – Free Resources – TCP Operations

December 30, 2017 at 9:48 am


Here are the free resources surrounding the Explain TCP Operations section of the CCIE R&S Written version 5.1 exam.

1.1.e Explain TCP Operations

  • 1.1.e.i     IPv4 and IPv6 PMTU
  • 1.1.e.ii    MSS
  • 1.1.e. iii  Latency
  • 1.1.e. iv  Windowing
  • 1.1.e.v    Bandwidth delay product
  • 1.1.e.vi   Global synchronization
  • 1.1.e       Options

TCP Performance – The Internet Protocol Journal – Volume 3, No. 2

Resolve IP Fragmentation, MTU, MSS, and PMTUD Issues with GRE and IPSEC

IP Application Services Configuration Guide, Cisco IOS Release 15M&T

IPv6 Addressing and Basic Connectivity Configuration Guide, Cisco IOS Release 15M&T

IP SLAs Configuration Guide, Cisco IOS Release 15M&T

TCP Options

TCP Global Synchronization 

TCP/IP Illustrated, Volume 1


Rapid Spanning Tree Protocol (RSTP) 802.1w

December 29, 2017 at 8:10 am


Whether you are pursuing your CCNA, CCNP, CCIE, or many other Cisco Certifications, a deep knowledge of RSTP is critical. In this post, we will detail key facts for you regarding this Layer 2 loop prevention system.

  • 802.1w (RSTP) is an evolution of the classic 802.1D (STP) protocol
  • 802.1D tried to speed things up with the additions of UplinkFast, BackboneFast, and PortFast; the UplinkFast and BackboneFast features are now essentially built into RSTP, while PortFast is still a feature you enable in RSTP if desired
  • 802.1w can also revert back to 802.1D in order to interoperate with legacy bridges on a per-port basis
  • With 802.1D, once in the forwarding state, there is no way to tell from the port state whether the port is root or designated; RSTP decouples the role and the state of a port to address this issue
  • The 802.1D port states are Disabled, Blocking, Listening, Learning, Forwarding; in 802.1w these are simplified to Discarding, Learning, Forwarding
  • The port roles are expanded in 802.1w to include Backup and Alternate ports in addition to Root and Designated; these new port roles help implement the features of UplinkFast into the protocol natively
  • A Backup port receives more useful BPDUs from the same bridge it is on and is a port blocked
  • An Alternate port receives more useful BPDUs from another bridge and is a port blocked
  • RSTP now uses all six bits of the flag byte that remain in order to perform – encoding the role and state of the port that originates the BPDU and handling the proposal/agreement mechanism
  • The RSTP BPDU is now of type 2, version 2; legacy bridges must drop this new BPDU; this makes it easy for an 802.1w bridge to detect legacy bridges connected to it
  • BPDUs are sent every hello-time, and not simply relayed anymore’
  • BPDUs are now used as a keep-alive mechanism between bridges; a bridge considers that it loses connectivity to its direct neighbor root or designated bridge if it misses three BPDUs in a row; this fast aging of the information allows quick failure detection
  • To natively support the BackboneFast type behavior, RSTP accepts inferior BPDUs; when a bridge receives inferior information from its designated or root bridge, it immediately accepts it and replaces the one previously stored; this permits fast acceptance of a new Root port in the topology
  • Rapid transition is the most important feature introduced by 802.1w; RSTP is able to actively confirm that a port can safely transition to the forwarding state without having to rely on any timer configuration; in order to achieve fast convergence on a port, the protocol relies upon two new variables: edge ports and link type
  • RSTP can only achieve a rapid transition to the forwarding state on edge ports and on point-to-point links; the link type is automatically derived from the duplex mode of a port
  • A proposal/agreement process in RSTP aids in very convergence
  • The topology change notification process is overhauled in order to also aid in faster convergence and improve efficiency

For more details on these new features summarized here – check out Understanding Rapid Spanning Tree Protocol (802.1w) This document often forms the basis for plenty of RSTP-related written exam questions from CCENT to CCIE. Note that my summary document here covers most of those questions for you, however!



400-101 CCIE R&S Written – Free Resources – IP Operations

December 27, 2017 at 3:48 pm


1.1.d Explain IP Operations

1.1.d.i ICMP unreachable, redirect
1.1.d.ii IPv4 options, IPv6 extension headers
1.1.d.iii IPv4 and IPv6 fragmentation
1.1.d.iv TTL
1.1.d.v IP MTU

An Overview of TCP/IP

ICMP Redirects

IPv6 Extension Headers

Resolve IPv4 Issues

TTL Expiry Attack

Configuring IP Services 

Routing TCP/IP Volume 1 – 2nd Edition  – Chapter 1

400-101 CCIE R&S Written – Free Resources – Challenges

December 23, 2017 at 10:06 am


1.1.c Explain general network challenges

  • Unicast flooding
  • Out of order packets
  • Asymmetric routing
  • Impact of micro burst

Unicast Flooding 

Issues with Asymmetric Routing 

General Network Challenges 

Micro Burst Monitoring

Network+ Disaster Recovery Quiz 1

November 9, 2017 at 1:54 pm

Disaster recovery (DR) is a critical component in networking today. It can encompass policies, tools, and procedures to enable the recovery or continuation of vital technology following a natural or human-induced disaster. Enjoy this quiz on the subject with the scope being Network+ from CompTIA.

Network+ Quiz - Disaster Recovery 1

Congratulations - you have completed Network+ Quiz - Disaster Recovery 1. You scored %%SCORE%% out of %%TOTAL%%. Your performance has been rated as %%RATING%%
Your answers are highlighted below.
Shaded items are complete.