9 votes

Why non-blocking switch needed?

However, as the term suggests, "theoretical" maximum speed is just a theory and it rarely happens in real-life conditions. That depends on your life, I guess. In my day job, we try to ...
Jörg W Mittag's user avatar
8 votes
Accepted

Two switches, double connection, no LACP: how does it work?

Most likely, the rapid or the multiple spanning tree protocol RSTP/MSTP has been activated on the 1910 switch. With the unmanaged 1410 switch forwarding STP BPDUs (most do), the 1910 notices a loop to ...
Zac67's user avatar
  • 84.4k
7 votes

Two switches, double connection, no LACP: how does it work?

Most switches comes with Spanning Tree (STP) enabled by default. This protocols will detect the loop and disable one of the link to break it. The new switch you connect either has STP disabled or a ...
JFL's user avatar
  • 19.7k
5 votes

Switches in chain topology for ~40 devices

Currently we have 6 switches chained together, Don't do that. Long chains, rings, double rings in switching require special (often proprietary) protocols instead of spanning-tree. Some of these sail ...
Marc 'netztier' Luethi's user avatar
3 votes

Understanding VLAN Tagging for Network Segmentation

VLAN tagging is a way to label network traffic so switches can identify which Virtual Local Area Network (VLAN) a packet belongs to. It's crucial for network segmentation, improving security, and ...
jhonegresham's user avatar
2 votes
Accepted

how can a STP switch time out MAC addresses from the table in Listening state?

A switch can have learned MACs from other interfaces. So when a blocked port transitions to listening, there are already MAC addresses in the table and any MACs received on the listening port won't ...
Ron Trunk's user avatar
  • 67.5k
2 votes

Switches in chain topology for ~40 devices

An addition to Marc's totally valid answer: I am trying to justify why a different topology would be required for this network so that new equipment can be purchased. If there are no cabling/...
Zac67's user avatar
  • 84.4k
2 votes

Why are DNS packets processed by process-switched?

You have NAT and ip virtual-reassembly enabled on the router with what appears to be a 1 gigabit internet service (or at least it is connected on a 1 gigabit port). This can easily overwhelm the ...
FrameHowitzer's user avatar
2 votes

Why non-blocking switch needed?

Non-blocking is a quality in switches that tells you that a switch doesn't lose frames unless a destination/egress port reaches its maximum bandwidth. That knowledge provides peace of mind and ...
Zac67's user avatar
  • 84.4k
2 votes
Accepted

Why MLS2 Doesn't Get ICMP Packet To Where It Should?

We're missing a bunch of output here, but here is a working theory: PC1 (which is in VLAN 10) has a default gateway of 10.10.0.11 (MLS1). Due to Per-VLAN Spanning Tree Protocol (PVSTP+) blocking the ...
Angelos Vassiliou's user avatar
1 vote

How can I diagnose the cause of a Dell EMC S5224F-ON discarding output packets?

I'm not familiar with those Dell switches but I would try: (temporarily) shut down the port mirroring - it's quite possible that it puts significant stress on the frame buffer, in turn causing ...
Zac67's user avatar
  • 84.4k
1 vote

Why are DNS packets processed by process-switched?

The problem was solved by blocking a pool of IP addresses from Brazil; CPU load dropped from 90% to 30%. It is not clear why and why they sent a bunch of DNS requests to us. But why exactly these ...
Глеб Щеголев's user avatar
1 vote

Understanding VLAN Tagging for Network Segmentation

VLANs logically divide switches into separate, unconnected switches. Frames in one VLAN cannot be sent to an interface for a different VLAN. In order to connect to a device that communicates with ...
Ron Maupin's user avatar
  • 99.6k

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