JUNOS & ME
Networking and Troubleshooting
Technical blog of @DOOR7302
Introduction Recently I carried out tests in labs to evaluate the FlowSpec implementation on MX960 router with TRIO MPC cards. I used a 12.3 Junos release. Those tests have covered: - IPv4 blackholing traffic feature - IPv4 rate-limiting traffic feature...
As I'm currently studying DC certification track, I decided to setup my first vQFX lab. My current multi-vendors virtual LAB runs on ESXi, so I wished to keep my VMware hypervisor also for vQFX instances. I'm a lucky man, vmdk images for vQFX are now...
1/ Some terms, before: OAM for Operations Administration and Maintenance LFM for Link Fault Management EFM for Ethernet in the First Mile 2/ Introduction: OAM is intended for point-to-point or emulated p2p Ethernet links. The OAM block is optional, so...
This post covers: - OAM implementation on Junos - Default value of OAM LFM parameter (in relation with the Part 1) - Configuration / understanding: Neighbor discovery phase - Configuration / understanding: Remote loopback operation - Configuration / understanding:...
Last week, I worked on 2 small projects in 11.4 Junos. I should: - Find a way to automatically disable a physical link when LACP "flapped" too many times during a given time. - Find a way to automatically disable a physical link when too many CRC errors...
The aim of this post is to provide the detailed procedure for upgrading the Switch Control Boards (SCB) of an MX960 chassis in order to overcome some limitations of the old SCB that are : - Unable to use the full load of the 16x10GE card and to keep fabric...
I spent time on Junos routers (T and MX series) to understand how multicast replication works. I carried out some tests in lab to better understand how the multicast replication is done at the PFE level. This study was very useful for some multicast issues...
Troubleshooting Load-balancing is quite complex. Working on an operational team, I often need to know on which interface a given stream (IP or MPLS) will get out... Cisco IOX provides several cli commands to quickly compute and display the result of a...
During a complex case on Juniper platform, I looked for a tip to capture transit traffic on a MX960 with Trio cards. Indeed, I suspected a Junos box to rewrite transit mpls traffic with an unexpected exp value. As I love carry out reverse engineering,...
A simple op script, just for fun. Next blog post will be more serious :) FOR TERMINAL : 24 Rows / 80 Columns / font: Courrier New 10 The video can see here : The 'op' script is called lovejunos.slax. It has been tested with release 11.4. You can simply...
This post describes how multicast Next-Hop resolution and caching is done on Junos MX routers with Trio based cards. To have more information regarding the multicast replication see my previous post here : Multicast Replication. 1/ Introduction: PIM join...
I try to explain load balancing on MX. This post does not cover all the cases, but tries to summarize the default behaviour depending on the type of card: ICHIP or TRIO based, to provide which fields can be add or remove to compute the hash and finally...
Recently, we received in LAB 2 new MPC cards: - The MPC4e Combo card: 2x100GE + 8x10GE ports (MPC4E 3D 2CGE+8XGE) - The MPC4e 32x10GE ports (MPC4E 3D 32XGE) These 2 new cards need at least the Junos 12.3 and can be used on both dense chassis: MX960 and...
uRPF allows anti-spoofing embedded at forwarding plane level. Junos provides this feature for many years with several modes and options: Loose or Strict mode Active or Feasible paths uRPF data base Discard or not supported in the uRPF data base I carried...
The configuration of the load balancing parameters is done at the forwarding-option level. There are 2 parts, each one is related to a type of hardware: - hash-key : for Ichip based platforms on MX or T series FPC - enhanced-hash-key : for Trio based...
A new short post today for network support technicians, engineers... One thing that you usualy check when you manage a case regarding service disruption is packet loss! The first step is to check if you have packet loss at physical layer due to framing...
I was wondering if I can use the embedded tcpdump of Junos to monitor transit traffic. I found a way to do it and this short post explains how to do that. This tip works only on TRIO Line cards. My setup has been tested on Junos 12.3. I used several features:...
Hello, I'm very proud to post the story of Joao. He passed recently JNCIE-DC and became one of the firsts JNCIE x4. Joao is a "Juniper Fan" like me. I'm currently preparing JNCIE-DC as well, so I was so happy to read his experience. Enjoy Reading. David...
My VMX installation guide - VMX-installguide.pdf I'm currently writing the 2nd Edition of the MX Series book. In this new edition, I wrote a chapter dedicated to VMX. The 2nd edition of the book will be released in few months: stay tuned :) ! I spent...
I've planned to write posts during the next weeks regarding these subjects: - Enhanced-SCB's detailed migration procedure on MX960: get the full power of your MX and your 3D cards. - Understanding Hashing / Load-balancing on MX: for ichip/TRIO based cards....
I've scheduled to write a post regarding Junos load balancing but I must carry out more tests before writing it. So I decided to post my code of a troubleshooting 'op' script which allows to display in one command all protocols related information of...
Sometimes it may be very useful to monitor only protocol and link events especialy during maintenance windows. Hereafter, I monitor : - Link UP/DOWN - ISIS adj UP/DOWN - OSPF neighbor UP/DOWN - LDP neighbor/session UP/DOWN - MPLS LSP UP/DOWN - RSVP neighbor...
My previous post has presented an hidden command for analysing in real time fabric statistics. I've developed a small op script, for the MX platform, that provides in one command the PFE/Fabric IN/OUT statistics for all the Fabric Planes (0 to 5) for...
Hello, I've opened this blog to share my passion for networking and especially networking on Junos platform. I provide technical information only based on my experience, my tests in Lab and the public documentations. I'm a french guy and my english is...
Small tips for analyse the fabric stats. I mean packets stats (IN/OUT/Drops) between each PFE and the Fabric. Usually fabric stats can be observe by using the following cli command. Remember, that there are only 2 streams at fabric level: High and Low...
IS-IS Screams,
BGP peer flapping:
I want my mommy!
