Archive of posts with category 'Routing & Switching'

Juniper Direct vs Local Routes

Juniper routers consider a directly configured IP as a “local” route, except when you use /32 mask. Then it is a “direct” route. This caused me some confusion when creating...

Juniper Default ARP Policer

Juniper devices have a default ARP policer that drops ARP requests and responses over 150kbps. By default, this is an aggregate policer that applies to all interfaces. This can lead...

Juniper Branch SRX LACP Weirdness

Juniper SRX 300 Series firewalls may stop forwarding traffic in some situations. The firewall says it is forwarding the traffic, but it doesn’t work. Monitoring traffic looks OK, ARP entries...

Juniper QFX10K IPFIX Gotchas

IPFIX is problematic on the Juniper QFX10K switches. Documentation is sparse, and doesn’t have a complete configuration. Behavior changes between versions in undocumented ways. Here’s a couple of things I...

Juniper MX Upgrades Causing Overheating

Juniper changed the way they do temperature management on MX240 and MX480 chassis devices, somewhere between 15.1 and 17.3. The net result is that your chassis might run hotter after...

QFX Upgrades - Check Host Version

I came across a situation where a software upgrade failed for some members in a Juniper QFX Virtual Chassis. There is a known issue with upgrades with a certain configuration...

IPv6 Trends, SixXS Sunset and Project Planning

Native IPv6 availability continues to increase, leading to the sunset of SixXS services. But it looks like we don’t like starting any major IPv6 rollouts around Christmas/New Years, but instead...

VRRP Skew Time (and always be learning...)

It’s funny how you can work with something for years, but miss a small detail. This week I learnt about Skew Time for VRRP. The reason for it is completely...

NZ IPv6 & DNSSEC Update

A year ago I published a table of New Zealand ISP IPv6 support. At the time support was fairly poor. I’m pleased to report that things have gotten better over the...

IPv6-based Wi-Fi Hotspots

Apple’s 2015 WWDC event included a great session on IPv6 & TCP changes coming with iOS 9. There is a related post to the IETF v6ops mailing list here. The...

Brocade PyNOS Python Libraries

PyNOS v1.1 has been published. This is a python library that simplifies automating Brocade VDX systems. It is built on top of ncclient, and uses NETCONF to communicate with the VDX...

It's 2015: 'Supports IPv6' should mean full support

It’s 2015. ARIN is finally out of IPv4 addresses, more than 20% of Google users in the US are using IPv6…and vendors are still doing a half-assed job with IPv6...

Brocade Certified vRouter Engineer

If you’ve visited the Brocade website recently, you’ve probably seen the “Free NFV Certification” banner. I signed up for this several months ago, but had put off completing the course. I...

IPv4 Address Transfer Prices Down?

Last year I wrote about the IPv4 Address Transfer Process. Recently I was involved in another IPv4 transfer. I was surprised to see that IPv4 prices have fallen in the...

F5 Data Groups, Wildcards and tmsh

Just a quick note about a problem I ran into with adding data groups to an F5 system using tmsh. I wanted to add a string data group containing a list...

The Year of IPv6?

IPv6 adoption has been slow. But I think it’s reaching a tipping point. I’m very close to calling 2015 “The year of IPv6.” There’s plenty of people who won’t believe...

VeloCloud & Information Brokerage

VeloCloud was the first presenter at Network Field Day 9. They are one of the new breed of SD-WAN vendors. I’m impressed by what they’re doing, and and the potential it...

NFD9: Cumulus Networks

Cumulus Networks gave a great presentation at Network Field Day 9. They presented their vision of how they’re working to improve networking. But they were also clear about what they...

NFD9 Prep: SD-WAN

Software Defined WAN, or SD-WAN, looks to be a theme of Network Field Day 9, with presenters such as CloudGenix and VeloCloud showing us their offerings. At first glance, SD-WAN...

Updated Big Switch Labs

Just a quick note to say that Big Switch have updated their demo lab system. This is an entirely virtual lab environment that simulates a Big Switch network. You can...

Network Field Day 9

I had a fantastic time at Network Field Day 8, and now I’ve been lucky enough to be invited back to NFD9 this February.

Rate my IOS?

Review schemes are useful for identifying good consumer products and applications. But that doesn’t mean that everything needs to prompt me to leave a review. Cisco has started prompting for reviews for IOS versions, but...

Big Switch Chaos Monkey Network Testing

Whenever you build a complex system, you need to test that it works as expected, including properly handling failures. It’s easy enough to do simple component failure testing, but harder to...

iRules/Tcl - Watch the Comments

It’s pretty common practice to ‘comment out’ lines in scripts. The code stays in place, but doesn’t get executed. Perfect for testing, when you might need more debug output, or you want...

War Stories: Cursed VLANs

This article is Part 7 in a 12-Part Series. Part 1 - War Stories: Loops that Permanently Broke the Network Part 2 - War Stories: Switches Lying about Duplex Mismatches...

Cumulus in the Campus?

Recently I’ve been idly speculating about how campus networking could be shaken up, with different cost and management models. A few recent podcasts have inspired some thoughts on how Cumulus Networks might fit...

HP SDN App Store Launches

HP’s SDN App Store has finally seen the light of day. This is intended to be a common platform for users and developers, to find and distributed real-world, practical SDN applications....

The Chassis Switch is Dead

The Chassis Switch is Dead. For most networks, chassis-based switches are no longer appropriate due to cost, inflexibility and risk. I see this as similar to servers, in that server...

Rant: Just stop it with the TFTP

TFTP was first defined in 1980. That is a very long time ago in IT, and while it’s had a good run, it’s time for network engineers to stop using...

War Stories: Gratuitous ARP and VRRP

This article is Part 6 in a 12-Part Series. Part 1 - War Stories: Loops that Permanently Broke the Network Part 2 - War Stories: Switches Lying about Duplex Mismatches...

HP2910al - Memory Leak with W.15.14.0007?

I have an HP 2910al switch in my lab. I was running firmware version W.15.12.0012, but needed to upgrade, to fix a bug where “~” gets added to the snmp...

HP Network Simulator - VirtualBox Version Issue

HP has released an updated Network Simulator. This uses VirtualBox to provide a hypervisor, as opposed to QEMU in earlier versions. When I tried it previously, it was unusably slow....

Network Field Day 8 - I'm Going!

I am lucky enough to be invited to attend Network Field Day 8 this September, in Silicon Valley. For 3 days, I get to hang out with some of the smartest people...

HPN Script Repository on GitHub

Dobias van Ingen is working to get an HP Networking scripting community together. This is to take advantage of various HPN scripting capabilities, such as:

APNIC - final 'final' /22 now available

APNIC entered their “final /8” phase in April 2011. From that time, new and existing APNIC members could request a maximum of one IPv4 /22 prefix. Once you had requested...

War Stories: Proxy ARP Auto-Configuration

This article is Part 5 in a 12-Part Series. Part 1 - War Stories: Loops that Permanently Broke the Network Part 2 - War Stories: Switches Lying about Duplex Mismatches...

Proxy ARP Sucks

Proxy ARP was often used in network designs 10–15 years ago, to enable NAT. It helped get around some specific challenges, but it was always an administrative hassle, and caused...

Transparent Caching Won't Save Us

A recent Gigaom article asks: “Will transparent caching reshape the future of video on the internet?”

IOS-XR: Stuck between SNMP and SDN

SNMP may be outdated, and is definitely unloved, but it still serves a purpose. We’re moving to a new world, with new methods and data structures for interrogating and configuring...

SDN for Enterprise

SDN is the buzzword du jour in the networking industry, but it’s hard to make sense of what it might mean for “normal” people. Here’s my take on what SDN...

The Fibre Future is Coming

In New Zealand, one company controls the copper cabling delivered to houses. They sell access to Retail ISPs, at a fixed price. Individual customer connections are mapped through to the...

Best of Interop - Look at the Categorisation

The “Best of Interop 2014 Finalists” have been announced. Pretty much all the products and technologies that you would expect, but I found the categorisation interesting. As you’d expect, there’s...

Dell Fabric Manager & The Future for CCIEs

Network Field Day 7 had many interesting presentations and discussions. I’m still working through them all, but one from Dell caught my eye, where they declared that CCIEs were no...

IPv4 Address Transfer Process

IPv4 exhaustion is a real issue for large parts of the world. IPv6 is the long-term solution, but it doesn’t solve today’s problems facing ISPs. Alternatives are needed - either...

HP Simware - Comware OS Simulator

HP recently released “Simware”, a Comware network simulator that lets you create test networks of emulated Comware switches and routers. This can be used to create “virtual” networks, ideal for...

Meraki AP Trial

Cisco Meraki offers a free wireless AP to anyone who registers for a webinar about their products. I had given up on receiving my AP, but after a moan on...

HP VSR Portal Redirection

When implementing HP IMC UAM, you may need to redirect users to the IMC webserver, for device registration & configuration, and obtaining user 802.1x certificates. One method of doing this...

War Stories: Switches Lying about Duplex Mismatches

This article is Part 2 in a 12-Part Series. Part 1 - War Stories: Loops that Permanently Broke the Network Part 2 - This Article Part 3 - War Stories:...

HP Wireless Future: Reading the Tea Leaves

Recently I posted some speculation about where HP is going with their Comware and ProCurve networking lines. But what about the wireless gear? Where’s that going? As before, I have...

HP Comware vs ProCurve: Reading the Tea-Leaves

HP acquired 3Com in 2009. This added a large range of routing, switching and wireless networking to HP - but they already had existing ProCurve wired and wireless hardware. Clearly...

War Stories: Loops that Permanently Broke the Network

This article is Part 1 in a 12-Part Series. Part 1 - This Article Part 2 - War Stories: Switches Lying about Duplex Mismatches Part 3 - War Stories: Check...

The HP SDN APP Store - It Might Just Work

HP has been laying out their SDN vision over the last few months. They want to develop a complete SDN ecosystem, including an Open Standards-based network that can integrate with...

DHCPv6 on Juniper SRX-110 - Progress

Last year I posted about my frustrations with getting the DHCPv6 client working on a Juniper SRX-110. I am pleased to report that Juniper has now released 12.1X46-D10.2, which resolves...

SDN App Stores - My Network is not a Phone

I’ve been thinking a lot about HP’s SDN App Store approach. In case you missed it, HP’s vision is to deliver an App Store for SDN applications, similar to Apple’s...

HP VSR1000 - Getting Started

HP’s “VSR1000 Virtual Services Router” is now generally available. This was first announced at Interop Las Vegas in May, but it wasn’t until Interop NYC in September that it started...

DHCPv6 Client on Juniper SRX-110

Juniper recently released 12.1X45-D10 for the SRX-110. The key new feature for me was DHCPv6 Client support - finally! It’s still new, and buggy, and I wouldn’t rush it into...