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Networking, Cloud, SRE and Automation

  • About
  • Security
    • IKEv1 IPSec messages breakout
    • VPN and MTU size
    • Determining MTU size for VPN connections
    • Palo Alto search for SSL decrypted packets
  • Cloud
    • AWS
    • GCP
    • Azure
      • Azure Policy based VPN
      • Azure + On-Prem eBGP Failover
      • Azure Vnet to Vnet peering
      • Connect Ansible to Azure
      • Azure change BGP weight
      • Azure CLI JSON query
  • Automation
    • Ansible
      • Ansible Cisco ASA backup
      • Ansible variable from line argument
    • Python
      • Parsing mac address with regex
      • Python traffic generator
      • Start and de-allocate VM from CLI in Azure
      • Connecting Git to remote repository
  • Networking
    • OSPF states
    • Spanning Tree TCN & BPDU
    • STP Topology change notification
    • STP Cost change
    • STP Backbone Fast
    • Spanning Tree UplinkFast
    • MST acronyms explained
    • Rapid Spanning Tree
  • Linux and Open-source
    • Wireshark and SNI
    • tcpdump – filter Path MTU messages
    • Linux route-based VPN + eBGP
    • NetBox API request
    • NetBox adding objects over API
    • Remote access VPN IKEv2
    • Check vendor with API
    • tcpdump – filter Path MTU messages
  • K8s
    • Build Kubernetes cluster
  • TLS
  • NGINX
    • Prefix rewrite
  • Docker
  • Search Search

Category: R&S

Post Categories R&S
Post dateOctober 22, 2021Post last updated dateUpdated October 22, 2021

OSPF states

Post author
Avatar pawel pawel
Post read time25 sec read
OSPF states, so I won’t never forget them 😉 DOWN No hellos have yet...
Post tagsccie, ospf, routing0
Post Categories Automation Azure Cloud R&S Security VPN
Post dateSeptember 30, 2021Post last updated dateUpdated November 2, 2021

Azure Policy based VPN

Post author
Avatar pawel pawel
Post read time1 min read
By default, Azure uses route based VPN if we select IKEv2 option (either we...
Post tagsazure, cloud, routing, vpn0
Post Categories Automation Linux and Open-source Python R&S
Post dateSeptember 30, 2021Post last updated dateUpdated November 2, 2021

Parsing mac address with regex

Post author
Avatar pawel pawel
Post read time1 min read
Vendors use different mac address format. When capturing mac address or arp table, output...
Post tagsautomation, linux, python0
Post Categories R&S
Post dateJuly 16, 2021Post last updated dateUpdated July 16, 2021

MST acronyms explained

Post author
Avatar pawel pawel
Post read time5 sec read
I’ve come across this picture. IMO it is the best explanation I could find...
Post tagsmst, stp0
Post Categories R&S
Post dateJune 23, 2021Post last updated dateUpdated June 23, 2021

STP Backbone Fast

Post author
Avatar pawel pawel
Post read time49 sec read
Introduction In normal STP 802.1D operation, if one of the leaf switches receive an...
Post tagsstp0
Post Categories R&S
Spanning Tree TCN & BPDU
Post dateMarch 14, 2021Post last updated dateUpdated April 5, 2021

Spanning Tree TCN & BPDU

Post author
Avatar pawel pawel
Post read time1 min read
Introduction This post explains flow of BPDU and TCN behaviour of full converged STP...
0
Post Categories R&S
Post dateJanuary 26, 2021Post last updated dateUpdated January 26, 2021

STP Cost change

Post author
Avatar pawel pawel
Post read time33 sec read
Introduction In spanning tree, path with the lowest cost towards root bridge it’s preferred....
Post tagsspanning tree, switching0
Post Categories R&S
Post dateJanuary 19, 2021Post last updated dateUpdated May 16, 2021

Spanning Tree UplinkFast

Post author
Avatar pawel pawel
Post read time3 min read
Introduction Uplink fast is a feature of STP that allows very fast converge in...
Post tagsspanning tree, stp, switching0
Post Categories R&S
Post dateJanuary 19, 2021Post last updated dateUpdated January 19, 2021

STP Topology change notification

Post author
Avatar pawel pawel
Post read time54 sec read
Introduction Topology change notification is not generated when ALT/BLK port state changes. Topology S1...
Post tagsspanning tree, switching0

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Recent Comments

    Recent Posts

    • Envoy 503 race condition
    • Send SNI with cURL
    • Azure Vnet to Vnet peering
    • Wireshark and SNI
    • OSPF states

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    Recent Comments

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