Mike Lossmann
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mikelossmann.bsky.social
Mike Lossmann
@mikelossmann.bsky.social
85 followers 78 following 110 posts
Networking Thought Leader and Speaker. Self Proclaimed Coffee Snob, Bourbon Enthusiast, Network Architect turned Technical Evangelist. My opinions are my own.
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mikelossmann.bsky.social
Nine episodes. Started with what BGP is. Ended with confederations and address families.

If you watched all of it, you actually understand BGP now. Final episode.

youtu.be/Wi0I7OPbHnM #BGP #NetworkEngineering #BourbonAndBGP #Cisco #CCIE #CCNA #CCNP #Networking
https://youtu.be/Wi0I7OPbHnM
youtu.be
September 21, 2026 at 3:10 PM
mikelossmann.bsky.social
Nine episodes. Thirteen blog posts. A lot of bourbon.

Everything we covered, what stuck, and what you should build next.

bit.ly/4x05y06 #BGP #NetworkEngineering #BourbonAndBGP #Cisco #CCIE #CCNA #CCNP #Networking
https://bit.ly/4x05y06
bit.ly
September 21, 2026 at 2:10 PM
mikelossmann.bsky.social
You've been using BGP for IPv4 and assuming that's the whole story.

It's not. IPv6, MPLS VPNs, EVPN. All of it runs on BGP through address families.

New video: youtu.be/_wzUe6KzmRE #BGP #NetworkEngineering #BourbonAndBGP #Cisco #CCIE #CCNA #CCNP #Networking
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https://youtu.be/_wzUe6KzmRE
youtu.be
September 14, 2026 at 3:10 PM
mikelossmann.bsky.social
BGP doesn't just route IPv4. It handles IPv6, MPLS VPNs, and EVPN through address families.

Most people skip this part until they're actually stuck on something.

bit.ly/3Ukitwd #BGP #NetworkEngineering #BourbonAndBGP #Cisco #CCIE #CCNA #CCNP #Networking
https://bit.ly/3Ukitwd
bit.ly
September 14, 2026 at 2:10 PM
mikelossmann.bsky.social
There's another way to fix iBGP scaling besides route reflectors. Almost nobody talks about it at work.

BGP Confederations. Sub-ASes. eBGP-like sessions inside your own AS.

New video: youtu.be/sXg_DftPyoY #BGP #NetworkEngineering #BourbonAndBGP #Cisco #CCIE #CCNA #CCNP
https://youtu.be/sXg_DftPyoY
youtu.be
September 7, 2026 at 3:10 PM
mikelossmann.bsky.social
Confederations split one AS into sub-ASes. From outside you're still one AS. Inside, sub-ASes use eBGP-like sessions.

Full mesh stops being your problem.

bit.ly/4q2iNv4
#BGP #NetworkEngineering #BourbonAndBGP #Cisco #CCNA #CCNP #CCIE #Networking
https://bit.ly/4q2iNv4
bit.ly
September 7, 2026 at 2:10 PM
mikelossmann.bsky.social
BGP session is up. Routes are in the table. Traffic is dead.

The next-hop points somewhere your internal routers can't reach. next-hop-self fixes it.

bit.ly/4wj454z#BGP #NetworkEngineering #BourbonAndBGP #Cisco #Juniper #Arista #Cisco #CCNA #CCNP #CCIE #Routing
September 2, 2026 at 2:10 PM
mikelossmann.bsky.social
iBGP session is up. Routes are showing up. Traffic fails after one hop and you have no idea why.

The next-hop isn't self. That's why.

New video: youtu.be/j5OHltZFLTI

#BGP #NetworkEngineering #BourbonAndBGP #Networking #Juniper #Arista #Cisco #CCNA #CCNP #CCIE #Routing
youtu.be
August 31, 2026 at 3:10 PM
mikelossmann.bsky.social
iBGP requires a full mesh. 50 routers means 1,225 sessions. Route reflectors fix this. One router re-advertises to the rest.

bit.ly/4xlqZJw #BGP #NetworkEngineering #BourbonAndBGP #Cisco #CCNA #CCNP #CCIE #Routing
August 31, 2026 at 2:10 PM
mikelossmann.bsky.social
There's a gap between understanding BGP and actually getting it running. You'll find it the first time a neighbor won't come up and you don't know why.

New video: youtu.be/c_chTBsvhoA

#BGP #NetworkEngineering #BourbonAndBGP #Networking #Cisco #CCNA #CCNP #CCIE
August 24, 2026 at 3:10 PM
mikelossmann.bsky.social
Reading about BGP and actually configuring it are different skills. You'll figure that out the moment you stare at a neighbor that won't come up and have no idea why.

Cisco, Juniper, Arista configs inside.

bit.ly/4bAVDpP #BGP #NetworkEngineering #BourbonAndBGP #Networking #Cisco #CCIE #CCNA #CCNP
August 24, 2026 at 2:10 PM
mikelossmann.bsky.social
You know what BGP does. Now someone's asking if your network actually needs it.

Short list of things that force the answer to yes. You might not be on it.

bit.ly/4wdQ1dn

#BGP #NetworkEngineering #BourbonAndBGP #Networking #Cisco #CCNA #CCNP #CCIE
August 19, 2026 at 2:10 PM
mikelossmann.bsky.social
BGP runs a 13-step algorithm every time it picks a path. Most people only know the first four.

The other nine are why your traffic does unexpected things at 2am.

New video: youtu.be/8mCSOFAtxM8 #BGP #NetworkEngineering #BourbonAndBGP #Networking #CCIE #CCNA #CCNP #Cisco
August 17, 2026 at 3:10 PM
mikelossmann.bsky.social
Everyone memorizes BGP best path for a cert then forgets it immediately. Don't.

This is the algorithm that decides where your traffic actually goes. 13 steps, in order.

bit.ly/4wkEZmJ

#BGP #NetworkEngineering #BourbonAndBGP #Networking #Cisco #CCNA #CCNP #CCIE
August 17, 2026 at 2:10 PM
mikelossmann.bsky.social
BGP doesn't care about your hostname or your IP. It cares about your ASN.

Public, private, 2-byte, 4-byte. There's more to this than you think.

New video: youtu.be/lf6yBxVsVgA

#BGP #NetworkEngineering #BourbonAndBGP #Networking #Cisco #CCNA #CCNP #CCIE #BourbonAndBGP
August 10, 2026 at 3:10 PM
mikelossmann.bsky.social
BGP doesn't care about your hostname. It cares about your ASN.

Public, private, 2-byte, 4-byte. There are more types than most people realize until they actually need one.

bit.ly/4fhmKbO

#BGP #NetworkEngineering #BourbonAndBGP #Networking
August 10, 2026 at 2:10 PM
mikelossmann.bsky.social
10 iBGP routers = 45 sessions. 50 routers = 1,225 sessions. All of it by hand.

This is why iBGP doesn't scale and why route reflectors exist.

bit.ly/4pAwCAH

#BGP #NetworkEngineering #NetworkArchitecture #NetworkEngineer #Cisco #CCNA #CCNP #CCIE #Networking
August 5, 2026 at 2:10 PM
mikelossmann.bsky.social
eBGP and iBGP look the same from the CLI. Same commands, almost identical config.

The rules are completely different. Miss the wrong one and you'll be staring at a broken session for an hour.

New video: youtu.be/rsQD42d_B2o #BGP #Networking #NetworkEngineering #NetworkArchitecture #Cisco
August 3, 2026 at 3:10 PM
mikelossmann.bsky.social
The sessions look identical. The commands are almost the same. Get the TTL, next-hop, or split horizon rule wrong and you'll wreck something.

eBGP vs iBGP. New post.

bit.ly/44ICluY #BGP #NetworkEngineering #NetworkArchitecture #NetworkEngineer #Cisco #CCNA #CCNP #CCIE #Networking
August 3, 2026 at 2:10 PM
mikelossmann.bsky.social
BGP runs the internet. Your ISP uses it. Every packet you send touches it at some point.

Nobody taught you this. That changes.

New video: youtu.be/HJCqZ0Cg6oM

#BGP #NetworkEngineering #NetworkArchitect #BourbonAndBGP #Networking
July 27, 2026 at 3:10 PM
mikelossmann.bsky.social
Someone mentioned BGP in your next design review. Before you touch a single neighbor statement, figure out if you actually need it.

Most networks don't. Seriously.

bit.ly/4wlEKrw

#BGP #NetworkEngineering #NetworkArchitect #Networking
July 27, 2026 at 2:10 PM
mikelossmann.bsky.social
BGP's been running the internet since 1994. Your ISP runs it. Your data center runs it. Someone told you it was a service provider protocol.

Wrong.

bit.ly/4pCGvhC #BGP #NetworkEngineering #Cisco #Networking
BIT.LY
July 22, 2026 at 2:10 PM
mikelossmann.bsky.social
OSPF rarely breaks randomly.
It exposes MTU mismatches, bad links, or forgotten configs.

Here’s a real-world guide to troubleshooting OSPF like an architect — practical, no slides.
bit.ly/3OUNcgk

#networking #OSPF #neteng #routing
OSPF Troubleshooting Guide: Fix Neighbor + Routing Issues Fast
A practical OSPF troubleshooting guide covering broken adjacencies, missing routes, and the fastest ways to diagnose issues.
bit.ly
February 25, 2026 at 3:30 PM
mikelossmann.bsky.social
OSPF gets a lot simpler after your first real outage.

Design lessons from the field:
protect Area 0, summarize early, respect redistribution.

Built from scars, not theory.

bit.ly/4cGMw8d

#OSPF #NetEng #Networking #Routing
February 24, 2026 at 3:30 PM
mikelossmann.bsky.social
OSPF isn’t magic.
It’s math, structure, and one very honest algorithm.

If you’ve ever wondered how routes are actually chosen, this dives into the SPF algorithm in plain English.

Clear, practical, architect-level.

bit.ly/3OrI0R1

#OSPF #Networking #Routing #NetworkEngineering #NetArch
February 23, 2026 at 3:30 PM