CCIE Data Center

The long rumored, highly expected and very desired has finally been released and it’s a beast!

Since the release of the Nexus platform there has been talk about when these platforms were to be introduced in a CCIE track. With the introduction of UCS in 2009 this became an even higher request especially since UCS really took off in sales. When I started my CCIE Storage studies in 2010 I initially wrote an article for IPexpert about my predictions for the CCIE DC (http://blog.ipexpert.com/2010/01/13/storage-and-datacenter-ccie/). Most of them where very easy guesses, but those also became reality in the track, though with new hardware that is now available (2 years later).

You might have already read most information on other blogs, but I’m trying to consolidate that information. During the coming weeks/months more and more information will become available and during Cisco Live in June there will be a huge amount of information and questions during the 4-hour Techtorial (TECCCIE-9544).

The scope of the exam is pretty much based on the usual suspects, so in summary you should know the:

  • UCS B-series blade systems
  • UCS C-series rackmount systems connected to UCS Manager via FEX
  • Virtual Interface Cards Continue reading

Nexus Accounting Log

Perhaps another trivial post, but if you don’t know about it, you might find it extremely useful. Cisco NX-OS has an on-device log file of the exec level configuration commands entered successfully. Obviously similar informational can be obtained from the TACACS logs, but there is a certain benefit in having directly on CLI. The command […]

Static Routes to an Interface, Not A Next-Hop

Static routes can be handy in some situations where you want to do some quick and (sometimes) easy routing to get the job done, whether replacing the job that a routing protocol would perform, or redistributing the static route into that protocol. The best way to do this would be to identify the remote subnet being routed to, and specify a next-hop IP address to send traffic to so that it can be reached.

Static Routes to an Interface, Not A Next-Hop

Static routes can be handy in some situations where you want to do some quick and (sometimes) easy routing to get the job done, whether replacing the job that a routing protocol would perform, or redistributing the static route into that protocol. The best way to do this would be to identify the remote subnet being routed to, and specify a next-hop IP address to send traffic to so that it can be reached.

Fast Restoration on IP – MPLS Fast ReRoute

Service providers that have a lot of real-time traffic through their network, like mobile network operators (MNOs), are very keen on a fast restoration of service once a failure occurs in the network. In the past a lot of networks were based on SDH/SONET transport networks, which took care of sub-second (50ms) failovers. Nowadays Ethernet is THE standard for any transport within a service provider network. This introduces an issue, as Ethernet is not built for automatic failover when certain things fail.

Now there are many ways to solve this and I want to dig deeper in these technologies in several posts.  I will discuss various protocols that can solve the fast restoration requirement in different ways. Some are used in local situations (so failover to local neighbor, like a twin sibling) and others can be used in inter-site locations or can be an end-to-end protection for certain traffic.

The posts are broken down as follows:

  1. MPLS Fast ReRoute (this post)
  2. IP Loop Free Alternate
  3. BGP PIC Core/Edge
  4. Hierarchical Forwarding

Please be aware that these technologies are all related to fast restore the layer 3 forwarding path, therefore restoring the MPLS forwarding path. The MPLS forwarding path may be Continue reading

LLDP / 802.1AB-2009 blows

If you're designing L2 discovery protocol, I suppose one of your mandatory requirements is, that you can 'machine walk' the network, after you find one box. I.e. you are able to know your neighbor devices and their ports. LLDP makes no such guarantees

You have 4 mandatory TLVs, [0123], End of LLDPDU, Chassis ID, Port ID and TTL. Chassis ID has 7 subtypes which implementation is free to choose, EntPhysicalAlias (two distinct cases), IfAlias, MAC address, networkAddress, ifName or locally assigned. Port ID also has 7 subtypes which implementation is free to choose, ifAlias, entPhysicalAlias, MAC address, networkAddress, ifName, agent circuit ID, locally assigned.

Now you can send what ever trash via locally assigned and be fully compliant implementation. It seems that it would be wise to mandate sending management address (networkAddress) in ChassisID and SNMP ifindex in PortID (and any _additional_ ones you may want to send, i.e. more than 1, which is not allowed). This way you'd immediately know what OID to query and from which node. Obviously this makes assumption that we have IP address always and SNMP implementation always. If we absolutely must support some corner cases where this is not true, we should Continue reading

JNCIE-ENT lab set-up

As I’m preparing for the various exams (up to the Expert lab) of the Enterprise Routing & Switching track of Juniper I needed a lab to support this. In this blogpost I would like to explain my choice of hardware and software and how I’m going to use this set-up to prepare for the written exams and the lab exam.

Hardware and Software

Based on the blueprint, available on the Juniper website (http://www.juniper.net/us/en/training/certification/resources_jncieent.html), I needed to select hardware and software. The current software version used in the lab is JUNOS 10.4. On the various communities I heard that they want to upgrade this to a JUNOS 11.x (probably 11.4, which is a long-term-support version) software track somewhere this year, but until that time I chose the latest version of 10.4. At time of this writing this is JUNOS 10.4R9.

On the official blueprint there is no real indication of which hardware is used on the lab exam, but when you find your ways through the community sites and with the help from some community friends (special thanks to Chris ;-) I decided to use the SRX100H as router and EX4200 Continue reading

OAM LFM: Part 2 – Junos implementation

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:...

OAM LFM: Part 2 – Junos implementation

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:...

OAM LFM: Part 2 – Junos implementation

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:...

Nexus load intervals

This is a interesting but a trivial post. Everybody know about the interface command “load-interval” that changes the time period over which the interface packet-rate and throughput statistics are averaged. I discovered an addition to this command on the Nexus the other day while poking around. NX-OS allows multiple counter intervals to be configured on […]

OAM LFM: Part 1 – The theory

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...

OAM LFM: Part 1 – The theory

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...

OAM LFM: Part 1 – The theory

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...

Logging – Levels


There are 8 different logging levels. Enabling higher level messages enables all lower level messages. EX: enabling Debugging level 7 enables all messages.


Level     Level Name         Description                                     Syslog Definition
0           Emergencies         The system is unusable                    LOG_EMERG
1           Alerts                   Immediate action is needed             LOG_ALERT
2           Critical                 Critical condition                             LOG_CRIT
3           Errors                  Error condition                                LOG_ERR
4          Warnings              Warning Condition                           LOG_WARNING
5     Continue reading
1 … 3,790 3,791 3,792 3,793 3,794 … 3,809