Find unknown static IP on device

How does the internet work - We know what is networking

If you work in networking sooner or later there will be a situation where someone will bring you a device that you must connect to your network that was used somewhere else before. That can be something like switch, Fiber channel switch, some security appliance, different controllers etc. In that case this device will often […]

Find unknown static IP on device

Syria shuts down the Internet

As of 10:27 UTC this morning the majority of the Internet in Syria is no longer connected to the rest of the world and can be considered as offline. Syria has only one major provider, AS29256 The Syrian Telecommunications Establishment. This provider is government owned and originates 56 out of 62 Syrian prefixes.

This morning between 10:26 and 10:27 all routes originated by AS29256 (The Syrian Telecommunications Establishment) were withdrawn and became unreachable.
The only Syrian prefixes left in the routing table are 5 prefixes originated by TATA, AS6453. These are the prefixes that are still reachable via TATA:
216.6.0.0/23, 63.243.163.0/24, 116.0.72.0/22, 66.198.39.0/24, 66.198.41.0/24

What happened?
We have no official confirmation about what happened, but similar events in the past [Syria, Egypt] were all government ordered. Because the primary telecom provider is state controlled in Syria, an outage like this is relatively easy to implement by ordering the primary telecom provider to shutdown the external links or BGP sessions with the external providers. External providers that provide services to Syria are:
AS9121 Turk Telecom
AS6762 telecom Italia
AS3491 PCCW Global
AS6453 Tata
Not the first outage

SAP – Session Announcement Protocol

How does the internet work - We know what is networking

Session Announcement Protocol as an experimental protocol designed for the purpose of multicasting a session’s information. IETF issued it as RFC 2974. SDP (Session Description Protocol) is being used by SAP as real-time transport protocol’s session depiction arrangement. With SAP use, correspondent can transmit SDP descriptions from time to time to an acknowledged multicast address […]

SAP – Session Announcement Protocol

The Failing Crusade Against NAT

After watching the recent epic that was the comment thread on networkingnerd’s NAT66 blog post from last year, I was initially persuaded to sit and watch from afar. I’ve had the opportunity to work with IPv6 quite a bit, and though I’ve done a few IPv6-related posts on the site, I still feel like there’s always something missing. After all, much of IPv6 is still just talk (sadly) and not enough wide-spread adoption to really put it through it’s paces.

The Failing Crusade Against NAT

After watching the recent epic that was the comment thread on networkingnerd’s NAT66 blog post from last year, I was initially persuaded to sit and watch from afar. I’ve had the opportunity to work with IPv6 quite a bit, and though I’ve done a few IPv6-related posts on the site, I still feel like there’s always something missing. After all, much of IPv6 is still just talk (sadly) and not enough wide-spread adoption to really put it through it’s paces.

Cisco UCS Manager 2.1 Highlights

Service Profile Renaming Yes, finally, you can rename service profiles. No more struggling to name your profiles perfectly the first time. When a profile is renamed, all the unique attributes including the MACs, WWNs, UUID, etc, are preserved. This can be done when the server is live and online without any impact. VM-FEX for Microsoft Hyper-V and KVM In addition to vSphere, VM-FEX (which I've written about here) is now available when using the Hyper-V or KVM hypervisors on UCS.

Recovery From Corrupt or Missing Software Image on Cisco device

How does the internet work - We know what is networking

This is a movie based on a true story. Is the issue you will have sooner or later if you are into networking and managing devices? Perhaps you will manage to upgrade hundreds of devices before you will see this happening but maybe it will be one of the first devices in production environment to […]

Recovery From Corrupt or Missing Software Image on Cisco device

My first received spam delivered over IPv6!

Not certain how much this actually counts as “Spam over IPV6″ though. It was only the last bit of delivery to my account where IPv6 was involved. It still originated from IPv4.

 
Received from relay-6.dlfw.twtelecom.net ([2001:4870:6082:1::72]) by he.net for ; Tue, 13 Nov 2012 11:57:38 -0800

Received from localhost (unknown [127.0.0.1]) by relay-6.dlfw.twtelecom.net (Postfix) with ESMTP id 223346021E; Tue, 13 Nov 2012 12:47:42 -0700 (MST)

Received from relay-6.dlfw.twtelecom.net ([127.0.0.1]) by localhost (relay-6.dlfw.twtelecom.net [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id TMxIEAmBj2TU; Tue, 13 Nov 2012 12:47:42 -0700 (MST)

Received from aol.com (unknown [209.234.184.51]) by relay-6.dlfw.twtelecom.net (Postfix) with SMTP id D73BD60094; Tue, 13 Nov 2012 12:47:32 -0700 (MST)

[Quality of Service] Part 2 – Bringing it Together: Cisco Nexus, Cisco UCS, and VMware

When you’re talking about something like MTU or QoS, it’s important to think about technology implementations in an end-to-end fashion by analyzing every possible path network traffic can take - always planning for the big picture and never simply a single connection between devices. For instance, poor planning can result in confusing QoS configurations that don’t match from device to device. Depending on the platform, this can result in mismatched MTU configurations, which at worst breaks your network and at best causes elusive performance problems that can be incredibly difficult to troubleshoot.

[Quality of Service] Part 2 – Bringing it Together: Cisco Nexus, Cisco UCS, and VMware

When you’re talking about something like MTU or QoS, it’s important to think about technology implementations in an end-to-end fashion by analyzing every possible path network traffic can take - always planning for the big picture and never simply a single connection between devices. For instance, poor planning can result in confusing QoS configurations that don’t match from device to device. Depending on the platform, this can result in mismatched MTU configurations, which at worst breaks your network and at best causes elusive performance problems that can be incredibly difficult to troubleshoot.

[Quality of Service] Part 2 – Bringing it Together: Cisco Nexus, Cisco UCS, and VMware

When you’re talking about something like MTU or QoS, it’s important to think about technology implementations in an end-to-end fashion by analyzing every possible path network traffic can take - always planning for the big picture and never simply a single connection between devices. For instance, poor planning can result in confusing QoS configurations that don’t match from device to device. Depending on the platform, this can result in mismatched MTU configurations, which at worst breaks your network and at best causes elusive performance problems that can be incredibly difficult to troubleshoot.

[Quality of Service] Part 1- Types of QoS Policies

There’s a lot of information out there about QoS and it’s an area where I’m only now starting to feel comfortable. I’ve been fortunate enough to have a decent amount of experience configuring datacenter equipment, especially in the context of a Flexpod, so I’ve been forced to know how all of these technologies play together with respect to QoS, which is very important when running sensitive applications like voice on such an infrastructure.

[Quality of Service] Part 1- Types of QoS Policies

There’s a lot of information out there about QoS and it’s an area where I’m only now starting to feel comfortable. I’ve been fortunate enough to have a decent amount of experience configuring datacenter equipment, especially in the context of a Flexpod, so I’ve been forced to know how all of these technologies play together with respect to QoS, which is very important when running sensitive applications like voice on such an infrastructure.

[Quality of Service] Part 1- Types of QoS Policies

There’s a lot of information out there about QoS and it’s an area where I’m only now starting to feel comfortable. I’ve been fortunate enough to have a decent amount of experience configuring datacenter equipment, especially in the context of a Flexpod, so I’ve been forced to know how all of these technologies play together with respect to QoS, which is very important when running sensitive applications like voice on such an infrastructure.

The Formation of “Brocatta” – Brocade Aquires Vyatta

Yes, I invented the word “Brocatta”, and I am not ashamed. The announcement was made today that Vyatta, a company that I’ve long used for their software routers and firewalls, has been acquired by Brocade. The move was not a surprise to me, as Brocade has yet to define a proper SDN strategy to compete with the announcement of Cisco’s Open Network Environment and onePK. Positioning Vyatta as Brocade’s “Software Networking” business unit is a good move because now Vyatta can operate more like an R&D department with better funding than I’m sure they’ve enjoyed thus far.

The Formation of “Brocatta” – Brocade Aquires Vyatta

Yes, I invented the word “Brocatta”, and I am not ashamed. The announcement was made today that Vyatta, a company that I’ve long used for their software routers and firewalls, has been acquired by Brocade. The move was not a surprise to me, as Brocade has yet to define a proper SDN strategy to compete with the announcement of Cisco’s Open Network Environment and onePK. Positioning Vyatta as Brocade’s “Software Networking” business unit is a good move because now Vyatta can operate more like an R&D department with better funding than I’m sure they’ve enjoyed thus far.

The Formation of “Brocatta” – Brocade Aquires Vyatta

Yes, I invented the word “Brocatta”, and I am not ashamed. The announcement was made today that Vyatta, a company that I’ve long used for their software routers and firewalls, has been acquired by Brocade. The move was not a surprise to me, as Brocade has yet to define a proper SDN strategy to compete with the announcement of Cisco’s Open Network Environment and onePK. Positioning Vyatta as Brocade’s “Software Networking” business unit is a good move because now Vyatta can operate more like an R&D department with better funding than I’m sure they’ve enjoyed thus far.

Unidirectional communication filter between two VLANs

How does the internet work - We know what is networking

Block Traffic among two VLAN’s but only in one way, how to do that? VLAN and VLAN configurations are very useful in all kinds of different ways. This configuration will be useful sooner or later for all network administrators out there. It was a big challenge to resolve this tricky communication security requirement. The problem actually does not […]

Unidirectional communication filter between two VLANs

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