Category Archives: Switching

Dell Networking OS10 using GNS3

Dell EMC Networking OS10 combines the best of Linux, open computing, and networking to advance open networking disaggregation. OS10 is a transformational software platform which provides networking hardware abstraction through a common set of APIs.
You can enable consistency across compute and network resources for your system operator (sysops) groups that require server-like manageability, as well as leverage your existing network con€guration.
You can simulate OS10 devices using OS10 VM appliances. The OS10 VM appliances execute the same software deployed on OS10-enabled hardware devices, with the exception of the hardware abstraction layer. The OS10 VM hardware abstraction layer simulates hardware devices in a VM environment.

All CLI commands as well as RESTCONF and SNMP interfaces are available in the OS10 simulation environment. You can build sandbox environments to learn open networking concepts, and prototype network operations and scripts risk-free.

Dell OS10

OS10 simulation features

All OS10 CLI commands and north-bound interfaces (RESTCONF, SNMP) are available including:

  • System management (SSH, AAA, DHCP, and so on)
  • Management port

L3 data plane and control plane (using Linux functionality)

Partial support for L2 data plane and control plane (using Linux functionality):

  • LACP
  • VLAN
  • LLDP
  • VLT

OS10 feature limitations

  • No ACL or QoS support (NPU is not available) — ACL and QoS CLI commands are available (but have no effect on trafc)
  • Limited L2 functionality (NPU is not available on simulator) — no spanning-tree control plane functionality
  • No breakout mode for simulated ports
  • Defaults to S6000-ON hardware platform simulation


  • Workstation or laptop with 16 GB RAM or larger recommended
  • 64-bit x86 CPU with 2 GHz or faster core speed (dual-core or larger recommended)
  • SDD with 64 GB available space
  • Virtualization environment — you can use either Windows, Linux, or VMware ESXi as a host system for the GNS3 Server VM environment
  • VMware ESXi server recommended for large network simulation




Cisco Live Barcelona 2018 here i GO!

This is going to be my 2nd Cisco Live, and i’m very excited because i’ve learned a lot over the past 8 years and i’m in a different professional stage at the moment that 8 years ago it was just a dream. I’m a strong believer that these events are important to grow your “networking” and keep you updated on new trends/technology.

So how my calendar looks like so far?

  • CCDE Techtorial and Exam
  • Firepower
  • ISE
  • Multi-Cloud
  • SD-X
  • DevOps

If you are are around, lets grab a beer and crack some of the topics above

Cisco Catalyst reborn

Cisco announced a new platform, Catalyst 9k (fixed and modular), a new hit for the Enterprise Architecture.

Some of the benefits i’ve captured:

  • Secure segmentation with SD-Access
  • Unmatched 60W POE on every access port
  • DNA Center
  • IoT readiness
  • Cloud readiness
  • IOS-XE
  • UADP 2.0
  • StackWise Virtual
  • IEEE1588
  • MACsec256
  • Encrypted Traffic Analysis (ETA)
  • Licensing mode changed (no info yet)

Catalyst 9300

Catalyst 9400

Catalyst 9500


L2TPv3 Tunneling

There are different L2VPN technologies like L2TPv3, VPLS, H-VPLS, AToM. Except L2TPv3, the others require a MPLS backbone. L2TP uses IP protocol 115



  • Layer 2 Tunneling Protocol v3 (L2TPv3)
  • Any transport over MPLS (AToM)


  • Virtual Private LAN Service (VPLS)
  • Hierarchical Virtual Private LAN Service (H-VPLS)

Payload agnostic

  • supports Ethernet, Frame-Relay, ATM, HDLC, PPP over IP
  • supports interworking (between different encap)

Note: Encapsulating means an extra MTU overhead, so we need to be careful to not fragmentation along the way.


The objective here is establish a Pseudowire (PW) between two routers (R2/R4) extending the Layer 2 between R1 and R5 for VLAN 156.

Assuming here we have connectivity for R2/R4 loopback’s, since we will use that as source for PW.

Configuration steps

  1. Define PW
    1. define local interface as the source of tunnel
  2. Define xconnect
    1. define peer, vcid and associate with PW recently created

vcid needs to be unique, in this case i choose the same as VLAN ID

R2(config)#pseudowire-class PW_156_L2TPV3
R2(config-pw-class)# encapsulation l2tpv3
R2(config-pw-class)# ip local interface Loopback0
R2(config-pw-class)# ip tos reflect

R2(config)#interface GigabitEthernet1.156
R2(config-subif)# encapsulation dot1Q 156
R2(config-subif)# no cdp enable
R2(config-subif)# xconnect 156 pw-class PW_156_L2TPV3

R4(config)#pseudowire-class PW_156_L2TPV3
R4(config-pw-class)# encapsulation l2tpv3
R4(config-pw-class)# ip local interface Loopback0
R4(config-pw-class)# ip tos reflect

R4(config)#interface GigabitEthernet1.156
R4(config-subif)# encapsulation dot1Q 156
R4(config-subif)# no cdp enable
R4(config-subif)# xconnect 156 pw-class PW_156_L2TPV3

R2#sh l2tun session all

L2TP Session Information Total tunnels 1 sessions 1

Session id 1881450243 is up, logical session id 32790, tunnel id 1984298019
Remote session id is 4260556922, remote tunnel id 82213150
Locally initiated session
Unique ID is 0
Session Layer 2 circuit, type is Ethernet Vlan, name is GigabitEthernet1.156:156
Session vcid is 156
Circuit state is UP
Local circuit state is UP
Remote circuit state is UP
Call serial number is 4100100002
Remote tunnel name is R4
Internet address is
Local tunnel name is R2
Internet address is
IP protocol 115
Session is L2TP signaled
Session state is established, time since change 00:00:06
2 Packets sent, 2 received
136 Bytes sent, 136 received
Last clearing of counters never
Counters, ignoring last clear:
2 Packets sent, 2 received
136 Bytes sent, 136 received
Receive packets dropped:
out-of-order:             0
other:                    0
total:                    0
Send packets dropped:
exceeded session MTU:     0
other:                    0
total:                    0
DF bit off, ToS reflect enabled, ToS value 0, TTL value 255
Sending UDP checksums are disabled
Received UDP checksums are verified
No session cookie information available
FS cached header information:
encap size = 24 bytes
45000014 00000000 ff73a16b 0a020202
0a040404 fdf2f07a
Sequencing is off
Conditional debugging is disabled
SSM switch id is 8212, SSM segment id is 4121

R2#sh l2tun tunnel all  

L2TP Tunnel Information Total tunnels 1 sessions 1

Tunnel id 1984298019 is up, remote id is 82213150, 1 active sessions
Locally initiated tunnel
Tunnel state is established, time since change 00:00:30
Tunnel transport is IP  (115)
Remote tunnel name is R4
Internet Address, port 0
Local tunnel name is R2
Internet Address, port 0
L2TP class for tunnel is l2tp_default_class
Counters, taking last clear into account:
70908 packets sent, 70725 received
5142824 bytes sent, 5127872 received
Last clearing of counters never
Counters, ignoring last clear:
70908 packets sent, 70725 received
5142824 bytes sent, 5127872 received
Control Ns 1925, Nr 56
Local RWS 1024 (default), Remote RWS 1024
Control channel Congestion Control is disabled
Tunnel PMTU checking disabled
Retransmission time 1, max 1 seconds
Unsent queuesize 0, max 0
Resend queuesize 0, max 3
Total resends 0, ZLB ACKs sent 51
Total out-of-order dropped pkts 0
Total out-of-order reorder pkts 0
Total peer authentication failures 0
Current no session pak queue check 0 of 5
Retransmit time distribution: 0 0 0 0 0 0 0 0 0
Control message authentication is disabled

Configuring OSPF

R1(config)#router ospf 1
R1(config-router)# log-adjacency-changes
R1(config-router)# network area 0
R5(config)#router ospf 1
R5(config-router)# log-adjacency-changes
R5(config-router)# network area 0

Confirm we have OSPF neighbouring across the L2VPN

R1#show ip ospf neighborNeighbor ID     Pri   State           Dead Time   Address         Interface        1   FULL/BDR        00:00:32      GigabitEthernet1.156


Do you like dissect packets? You can do it here

References: – Layer Two Tunneling Protocol – Version 3 (L2TPv3)

Cisco is raising up CCDA and CCDP to v3

Cisco is moving CCDA and CCDP to v3.

What topics were added/removed?


Topics Removed from the DESGN Exam:

  • Describe developing business trends
  • Describe network management protocols and features
  • Describe network architecture for the enterprise
  • Identify Cisco technologies to mitigate security vulnerabilities

Topics Added to the DESGN Exam:

  • Describe the Cisco Design lifecycle – PBM (Plan, Build, Manage)
  • Describe the importance and application of Scalability in a network
  • Describe the importance and application of Resiliency in a network
  • Describe the importance and application of concept of Fault Domains in a network
  • Design a basic branch network
  • Describe the concepts of virtualization within a network design
  • Identify network elements that can be virtualized
  • Describe Data Center components
  • Describe the concepts of Network Programmability within a network design


Topics Removed from the ARCH Exam:

  • Design for infrastructure services
  • Identify network management capabilities in Cisco IOS Software
  • Create summary-able and structured addressing designs
  • Describe IPv6 for campus design considerations
  • Describe the components and technologies of a SAN network
  • Create an effective e-commerce design
  • Create remote access VPN designs for the teleworker


Topics Added to the ARCH Exam:

  • Create stable, secure, and scalable routing designs for IS-IS
  • Determine IPv6 migration strategies
  • Design data center interconnectivity
  • Design data center and network integration
  • Select appropriate QoS strategies to meet customer requirements
  • Design end to end QoS policies
  • Design a network to support Network Programmability (SDN)
  • Describe network virtualization technologies for the data center

CCDA Exams & Recommended Training

Required Exam(s) Recommended Training
640-864 DESGN
Last day to test: December 14, 2015
Designing for Cisco Internetwork Solutions (DESGN) v2.1
200-310 DESGN Designing for Cisco Internetwork Solutions (DESGN) v3.0

CCDP Exams & Recommended Training

Required Exam(s) Recommended Training
300-101 ROUTE Implementing Cisco IP Routing (ROUTE)
300-115 SWITCH Implementing Cisco IP Switched Networks (SWITCH)
642-874 ARCH
Last day to test: December 14, 2015
OR300-320 ARCH
Designing Cisco Network Service Architectures (ARCH)ORDesigning Cisco Network Service Architectures (ARCH)