Do a Cleanup Before Automating Your Network

Remington Loose sent me an interesting email describing his views on the right approach to network automation after reading my Network Reliability Engineering Should Be More than Software or Automation rant – he’s advocating standardizing network services and cleaning up your network before trying to deploy full-scale automation.

I think you are 100% right to start with a thorough cleanup before automation. Garbage in, garbage out. It is also the case that all that inconsistency and differentiation makes for complexity in automation (as well as general operations) that makes it harder to gain traction.

netsim-tools Release 1.1.2

Every time I’m writing netsim-tools release notes I’m amazed at the number of features we managed to put together in just a few weeks.

Here are the goodies from netsim-tools releases 1.1.1 and 1.1.2:

netsim-tools Release 1.1.2

Every time I’m writing netsim-tools release notes I’m amazed at the number of features we managed to put together in just a few weeks.

Here are the goodies from netsim-tools releases 1.1.1 and 1.1.2:

BGP Route Reflector Myths

New networking myths are continuously popping up. Here’s a BGP one I encountered a few days ago:

You don’t need IBGP sessions between BGP route reflectors

In general, that’s clearly wrong, as illustrated by this setup:

BGP Route Reflector Myths

New networking myths are continuously popping up. Here’s a BGP one I encountered a few days ago:

You don’t need IBGP sessions between BGP route reflectors

In general, that’s clearly wrong, as illustrated by this setup:

Sample Lab: SR-MPLS on Junos and SR Linux

Last week I published a link to Pete Crocker’s RSVP-TE lab, but there’s more: he created another lab using the same topology that uses SR-MPLS with IS-IS to get the job done.

Jeroen Van Bemmel did something similar for SR Linux: his lab topology has fewer devices (plus SR Linux runs in containers), so it’s easily deployable on machines without humongous amount of memory.

Sample Lab: SR-MPLS on Junos and SR Linux

Last week I published a link to Pete Crocker’s RSVP-TE lab, but there’s more: he created another lab using the same topology that uses SR-MPLS with IS-IS to get the job done.

Jeroen Van Bemmel did something similar for SR Linux: his lab topology has fewer devices (plus SR Linux runs in containers), so it’s easily deployable on machines without humongous amount of memory.

Worth Reading: The Network Does Too Much

Tom Hollingsworth published a more eloquent version of what I’ve been saying for ages:

• Complexity belongs to the end nodes;
• Network should provide end-to-end packet transport, not a fix for every stupidity someone managed to push down the stack;
• There’s nothing wrong with being a well-performing utility instead of pretending your stuff is working on unicorn farts and fairy dust.

Obviously it’s totally against the vested interest of any networking vendor out there to admit it.

Worth Reading: The Network Does Too Much

Tom Hollingsworth published a more eloquent version of what I’ve been saying for ages:

• Complexity belongs to the end nodes;
• Network should provide end-to-end packet transport, not a fix for every stupidity someone managed to push down the stack;
• There’s nothing wrong with being a well-performing utility instead of pretending your stuff is working on unicorn farts and fairy dust.

Obviously it’s totally against the vested interest of any networking vendor out there to admit it.

Worth Exploring: Christoph Jaggi’s New Web Site

Christoph Jaggi, the author of Ethernet Encryption webinar and ethernet encryptor market overviews launched a new site in which he collected tons material he created in the past – the network security and news and articles sections are definitely worth exploring.

Worth Exploring: Christoph Jaggi’s New Web Site

Christoph Jaggi, the author of Ethernet Encryption webinar and ethernet encryptor market overviews launched a new site in which he collected tons material he created in the past – the network security and news and articles sections are definitely worth exploring.

Video: Kubernetes Architecture

Yesterday I mentioned the giant glob of complexity called Kubernetes. If you want to slowly unravel it, Kubernetes Architecture video from the excellent Kubernetes Networking Deep Dive webinar by Stuart Charlton is a pretty good starting point.

Video: Kubernetes Architecture

Yesterday I mentioned the giant glob of complexity called Kubernetes (see also more nuanced take on the topic). If you want to slowly unravel it, Kubernetes Architecture video from the excellent Kubernetes Networking Deep Dive webinar by Stuart Charlton is a pretty good starting point.

MTU Settings in Virtual Network Devices

When I finally¹ managed to get SR Linux running with netsim-tools, I wanted to test how it interacts with Cumulus VX and FRR in an OSPF+BGP lab… and failed. Jeroen Van Bemmel quickly identified the culprit: MTU. Yeah, it’s always the MTU (or DNS, or BGP).

I never experienced a similar problem, so of course I had to identify the root cause:

MTU Settings in Virtual Network Devices

When I finally¹ managed to get SR Linux running with netlab, I wanted to test how it interacts with Cumulus VX and FRR in an OSPF+BGP lab… and failed. Jeroen Van Bemmel quickly identified the culprit: MTU. Yeah, it’s always the MTU (or DNS, or BGP).

I never experienced a similar problem, so of course I had to identify the root cause:

Three Dimensions of BGP Address Family Nerd Knobs

Got into an interesting BGP discussion a few days ago, resulting in a wild chase through recent SRv6 and BGP drafts and RFCs. You might find the results mildly interesting ;)

BGP has three dimensions of address family configurability:

• Transport sessions. Most vendors implement BGP over TCP over IPv4 and IPv6. I’m sure there’s someone out there running BGP over CLNS¹, and there are already drafts proposing running BGP over QUIC².
• Address families enabled on individual transport sessions, more precisely a combination of Address Family Identifier (AFI) and Subsequent Address Family Identifier.
• Next hops address family for enabled address families.

Three Dimensions of BGP Address Family Nerd Knobs

Got into an interesting BGP discussion a few days ago, resulting in a wild chase through recent SRv6 and BGP drafts and RFCs. You might find the results mildly interesting ;)

BGP has three dimensions of address family configurability:

• Transport sessions. Most vendors implement BGP over TCP over IPv4 and IPv6. I’m sure there’s someone out there running BGP over CLNS¹, and there are already drafts proposing running BGP over QUIC².
• Address families enabled on individual transport sessions, more precisely a combination of Address Family Identifier (AFI) and Subsequent Address Family Identifier.
• Next hops address family for enabled address families.

More: Hardware Differences between Routers and Switches

Aaron Glenn sent me his thoughts on hardware differences between routers and switches based on the last paragraph of Dmytro Shypovalov’s views on the topic

To conclude, what is the difference between routers and switches in my opinion? I have absolutely no idea.

More: Hardware Differences between Routers and Switches

Aaron Glenn sent me his thoughts on hardware differences between routers and switches based on the last paragraph of Dmytro Shypovalov’s views on the topic

To conclude, what is the difference between routers and switches in my opinion? I have absolutely no idea.

Sample Lab: RSVP TE on Junos

It’s amazing how creative networking engineers become once they have the basic tools to get the job done a bit quicker. Last week Pete Crocker published the largest topology I’ve seen built with netsim-tools so far: a 13-router lab running RSVP TE to transport IP traffic between external autonomous systems¹.