Archive of posts with category 'Routing & Switching'
I recommend always using LACP for external connections. It will make your life easier, even when you only have a single connection. Here’s why we do it.
The BGP RFCs state that external BGP peers should insert their own AS into the AS PATH advertised to eBGP peers. Some peers strip their AS, generally for commercial gain....
Picking the right Junos version is important. If you’re not familiar with Juniper, finding and downloading the right software package is confusing. Here’s some guidance on picking the right version....
Juniper has a new enhanced four-post rack mount kit “JNP-4PST-RMK-1U-E” for their 1RU datacenter devices. It works with devices like the QFX5120 and PTX10001-36MR. It is much improved over the...
The Juniper EX3400 switch series is a decent access switch. But a Product Manager chose to save $0.50 on COGS by choosing a 2GB disk. That’s just not enough space...
I’ve written before about the default ARP policer on Juniper MX. It can create some odd failure conditions when you’re connected to noisy networks such as large Internet Exchanges. Junos...
Juniper Routing Engines with VM Host need an i40e NVM firmware upgrade. The procedure is a pain in the ass, and documentation is not great. But you can’t avoid the...
Juniper routers consider a directly configured IP as a “direct” route, except when you use a /32 mask (for IPv4). Then it is a “local” route. This caused me some...
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 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...
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 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...
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...
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...
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...
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...
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...
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. 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...
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...
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...
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...
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 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...
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...
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...
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...
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.
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...
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...
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...
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...
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’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. 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...
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...
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...
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 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....
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...
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 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...
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 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...
A recent Gigaom article asks: “Will transparent caching reshape the future of video on the internet?”
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 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...
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...
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...
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 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 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...
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...
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...
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:...
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 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...
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...
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...
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...
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’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...
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...
