1
vote
1answer
28 views

Connect access switches to router or core switch

My workplace consists of 4 access unmanaged network switches from three different computer rooms connected to a router. The router contains three 100mbps ethernet ports and one Gigabit (GigE) port. ...
2
votes
1answer
233 views

Is there a standard managed switch configuration protocol?

is there a vendor-independend managed switch configuration protocol e.g. for creating VLANs that can be run over TCP or serial port?
-2
votes
1answer
98 views

ethernet switch makes network down [closed]

I have a D-Link 8-port Ethernet switch which was perfectly working. Since 2 days ago it makes the entire network down. The problem is when I disconnect the cables it runs again and after I connect ...
3
votes
2answers
270 views

What does 'Si' mean with respect to network switches?

I am seeing references to Multilayer Switches with Si as in the network symbol below. What does the 'with Si' qualifier mean?
5
votes
3answers
384 views

Gigabit uplink versus regular switch port

I have a 10/100/1000 24-port + 2 mini-GBIC ports switch which I have to link to other switches. Unfortunately, on the other switch all the mini-GBIC slots are taken up, so all I can do is link them ...
0
votes
1answer
43 views

Ethernet switch signal quality

Is there a (significant) signal quality difference between ethernet switches? n other words: A 1000base-t, do some switches allow longer cable runs than other switches?
0
votes
2answers
147 views

Calculating required uplink capacity of network switch [duplicate]

Is there any common method (usable in practice) for estimating the uplink capacity of switch based on known number of users connected to this switch and the maximum internet speed they are allowed. ...
0
votes
1answer
32 views

Broadcast stop via loopback kills bandwidth

Why does creating a broadcast storm by directly connecting two ports on a switch cause the bandwidth to all the other ports to cease?
0
votes
0answers
44 views

ZyXel ES-2024 - Mirrored port showing duplicated traffic

I have a ZyXel ES-2024 PWD switch. I would like a computer plugged into port 26 to see all traffic that passes through port 2, both inbound and outbound. I have configured port mirroring for the ...
1
vote
1answer
50 views

Strategy for forcing cam table updates from custom hardware

I have a system that consists of a control PC, two layers of switches, and 50 custom devices. The PC continuously streams a total of 5.8MB/sec (6000 ethernet frames/sec) to the devices. I have ...
-2
votes
2answers
66 views

Network Switch Terminology (MAC address table) [closed]

When a switch has the ability to learn what MAC addresses each of its ports serves, then uses that to determine which port to send ethernet packets out, what is that feature called? Also, does every ...
0
votes
3answers
233 views

patch panels… or directly to the switch?

does it make a difference in terms of signal quality if I connect the Ethernet cabling: from the wall-plugs to the patch-panel and from the patch-panel to the switch with a cord. as opposed to: ...
2
votes
1answer
253 views

How can I stress an Ethernet managed Switch?

for testing purposes I need to stress an 8-port managed ethernet switch. Essentially, I want to simulate a scenario in which two hosts on the switch are exchanging data and the other hosts connected ...
1
vote
1answer
153 views

Maximum throughput on switch with different link speeds

While doing some benchmarking on a network app I discovered strange behavior that involves 100MBit and 1GBit ethernet clients connected through a switch (at-gs900/8e). I have one server (Gbit) and ...
0
votes
0answers
84 views

I have a firewall that supports 1Gbit ethernet ports but 1.4Gbit of traffic, can I make use of a 10Gbit pipe from the router in this case?

We're putting up a rack of servers in a datacenter which provides us either a 1Gbit pipe or 10Gbit pipe from the router (our choice, our package includes 10Gbit). But if we have a firewall which ...
0
votes
0answers
98 views

Routing traffic externally instead of internal loop

I have one Ubuntu box with 2 network cards. I am running netperf on the computer to measure performance of networking equipment, ethernet coming out of eth0 into the switch then back out into the ...
1
vote
3answers
847 views

Enabling jumbo frames on switch but not on devices: looking for trouble?

The switch at hand is a Dell PowerConnect 2716 which does support both VLANs and Jumbo Frames but, as far as I can understand from its manual, it only has a global Jumbo enable/disable setting and no ...
1
vote
0answers
1k views

Is it possible to mix jumbo frames VLAN and standard mtu VLAN on the same switch port?

If a managed switch and all attached devices both support VLANs and Jumbo Frames, is it possible to mix VLANs with jumbo frames and VLANs with standard frames on the same switch port / ethernet card? ...
-4
votes
2answers
125 views

What is the fastest way to connect two machines for a ping-pong test? [closed]

I need to do a latency test between two machines, basically a ping-pong packet test. I wonder what is the fastest connection I can have between those two machines. I imagine my options are: Ethernet ...
3
votes
2answers
2k views

Why is the link between my switch and my router always negotiating half-duplex mode?

I have a Cisco 2950 switch which has one of its ports connected to an Internet router provided by my ISP; I have no access to the router configuration, but I manage the switch. If I leave all switch ...
1
vote
2answers
3k views

Difference between ethernet switch and ethernet pass-through

Most blade server systems can have an ethernet switch module or an ethernet pass-through module. What is the difference between both? Is the pass-though module simply "dumb" as a hub? Why would you ...
4
votes
5answers
6k views

Does a single LACP channel over multiple switches increase redundancy?

I am curious for opinions, findings, or evidence that having multiple interfaces bonded using LACP to ports in multiple switches can increase redundancy. Previously bonded interfaces have always been ...
-2
votes
1answer
481 views

stacking two Dell 8024 rack switches

two Dell powerconnect 8024 (8024, 8024F)- rackmount how can these be tied togeather? stacked.. this would be used as interface for dedicated LAN
10
votes
3answers
411 views

Cut network cables in Cisco 2960 PoE

We've a Cisco 2960e that services our VoIP phones and other things. I inherited it. The question I have is the cut cables: there are about four network connectors that are cut about 1cm away from the ...
1
vote
2answers
2k views

Serial to ethernet cable: how to connect to device

How can I use a serial to ethernet cable to connect to a device: in my case a Hp ProCurve AP? A serial to USB or serial to serial would have been great but I found this serial to ethernet cable from ...
0
votes
2answers
97 views

Network topology

I am writing a network application that has several machines that serve separate clients, but machine themselves need to communicate with each other frequently. Let's say multiple chat servers for ...
0
votes
1answer
88 views

Would using a bridged connection on a machine allow the machines connected to it use the internet?

In this specific case I wish to connect my first computer wirelessly to a router, and have the laptop use a bridged connection to Ethernet to extend to other computers. The other two computers will ...
3
votes
4answers
1k views

Ethernet switch capacity question

We're looking at hooking up 48 small embedded systems with 10/100 Ethernet ports to an Ethernet switch and then have that switch talk to a server upstream via a faster connection. I have a couple of ...
3
votes
1answer
507 views

Daisy-chaining network switches with multiple cables

This might just be the dumbest question you'll ever read, but I digress. Say I have two 100Mbps Ethernet switches with 2 computers on each, connected together by a single cable. This way, the two PCs ...
0
votes
1answer
755 views

Switch Before Firewall / Router - Multiple public IPs

I currently Have a 10Mbit Full duplex circuit connected to a small unmanaged switch which then connects to a Sonicwall Firewall / Router. I have several public IP addresses (/28) that are assigned to ...
0
votes
3answers
193 views

How to maximise performance in computers connected into LAN via Gigabit ethernet router?

Our group is setting up a server (which might just be a NAS, but we're not sure yet), which shares files, so that it connects to all other computers in the room (about 10 of them). I am thinking just ...
0
votes
3answers
574 views

What is the difference between a hub and a switch?

I'm sneeking around online store for used stock of hubs, routers and switches for a project I have to build a network infrastructure. So far, I have bought: 1x Cisco 2514 Router; 5x Cisco Serial ...
2
votes
3answers
428 views

Ethernet: network topology

Consider a standard GigE network switch. In order to do the switching, presumably it needs to maintain a map of MAC addresses of all things that exist on the network to its (switch's) port numbers. ...
3
votes
3answers
185 views

Link mode on unmanaged gigabit switches

I have two RJ45 sockets connected by an inaccessible unknown-category twisted pair cable. I plug two unmanaged gigabit switches into the sockets using Cat6 cables, and they negotiate a 100Mbps link. I ...
4
votes
4answers
1k views

Determine switches between devices on LAN

I'm on a network where most devices are DHCP. If I have a few switches between device A and a DHCP server, how can I find out what they are? traceroute just gives me 1 hop, regardless of the number ...
1
vote
4answers
117 views

switch or other device?

i want to get a network device working as a multiplexer. for example, only the data sent to port A would be forwarded to port B completely. and the data of port B have to be forwarded to port A ...
2
votes
2answers
956 views

Core & Edge switch design: backplane as a point of failure?

We are in the midst of planning a re-cabling of the building and installing new switches. A few different designs have been proposed, and one such design puts our core switches at the heart of our ...
7
votes
5answers
8k views

What is the disadvantage to cascading multiple switches?

I have to wire a new office for ethernet and the contractors want to charge atrocious amounts for each line running to each room in the office. It will be much cheaper for me to run a single line to ...
3
votes
2answers
177 views

Ethernet NC lines and Switches

What to typical network switches do with the Ethernet NC lines (pins 4, 5, 7, and 8)? I'm considering a few (non-standard, for personal use only) projects where it would be very useful to have those ...
3
votes
6answers
3k views

Why do partially failed/failing switches fail to pass DHCP?

I've noticed this several times: a switch starts to behave oddly. Usually if the switch doesn't fail outright, what tends to get noticed is that DHCP doesn't work. We had a Linksys SRW-224P fail ...
1
vote
3answers
897 views

Full speed internal switch bandwidth but per-port set external bandwidth?

I am in an environment where all the machines are behind a switch that I don't have access to. Each ethernet wall port has limited bandwidth depending on how much has been paid for each port. The ...
2
votes
1answer
5k views

How does Brocade (Foundry) FastIron CX compare to Cisco 3750 stackable switches?

We're considering Brocade's CX series vs. Cisco's 3750 at both core and distribution layers for a new site with gig to desktop, without POE. If you have any hands-on experience with FastIron CX ...
0
votes
2answers
362 views

Recommendation for Ethernet switches that allow arbitrary network topologies [closed]

We have the following requirements for three Ethernet switches that will be connected together: Allow the switches to connect together to form dynamic, arbitrary topologies, i.e., support for the ...
1
vote
4answers
2k views

GigE ethernet switch backplane bandwidth

While looking for a 16- or 24-port gigabit ethernet switch with at least 6 VLANs and port mirroring (packet duplication to a monitoring port), I came up with three candidates (there are more): Cisco ...
0
votes
3answers
194 views

Switch Fabric Optimization

How does an ethernet switch work on a port-by-port basis? Specifications are given for the speed of the switch "fabric", but is that universal bandwidth through a central processor or are there ...
2
votes
6answers
2k views

Packets sent indiscriminantly out of switch

Switches are supposed to only send traffic to a system if it's intended for that system. Ours appears not to: if I run "tcpdump not host myhostname", I can see lots of packets that are clearly ...