Tagged Questions

1
vote
2answers
109 views

ethernet cable is connected but It shows unplugged [closed]

I told datacenter too connect two of my servers with a crossover cable to each other. But when I try this command ethtool eth0 Settings for eth0: Supported ports: [ TP ] Supported ...
0
votes
1answer
101 views

How do I calculate the ethernet NIC-to-NIC time to send a MTU packet (1500 bytes)? (OS-excluded) [closed]

I understand it will depend on the speed of the ethernet 10 Mbit to 100 Gbit. Given an ethernet speed, how do I calculate the time spend in the wire from NIC-to-NIC? I am assuming here that the ...
13
votes
1answer
835 views

What am I misunderstanding about calculating MTU?

Okay, I just finished resolving a jumbo frames issue between a few Xserves, a Netgear GSM7224, and a Drobo B800i. It turned out that the Xserves (Mac OS X 10.6.8 Server) and the Drobo B800i accept the ...
3
votes
3answers
135 views

What could cause two devices to refuse to link?

This is a curious case where all the devices at hand will link with one another, except for two that just won't detect one another. One device is a single board computer (SBC) with a gigabit nic, the ...
6
votes
1answer
396 views

What is theoretical maximum of TCP traffic over GigaEthernet?

What is theoretical maximum of TCP traffic over GigaEthernet ?
3
votes
4answers
860 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 ...
2
votes
1answer
149 views

What percentage of its capacity should I aim to run a network at?

First of all, apologies if this is the wrong StackExchange site for this question - it's about Ethernet network capacities, but not specifically about servers etc. I am designing a network for a data ...
0
votes
3answers
162 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 ...
3
votes
3answers
161 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 ...
2
votes
4answers
224 views

High speed network configuration

Sorry if this seems to be a stupid question, I'm not sure how to specify what I want to know when checking google. I will have 2 or 3 devices pumping out data on a 100Base-T port. The combined data ...
2
votes
1answer
4k 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 ...
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
184 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
276 views

information about ethernet cards

I have few question and I don't find right answers. What's the maximum speed of an Ethernet cable (not a phone cable! the one that has 8 threads) About the Gigabit Ethernet Network Card: Is it just ...
6
votes
9answers
5k views

Why does 1GBit card have output limited to 80 MiB?

I'm trying to utilize maximal bandwidth provided by my 1GiB network card, but it's always limited to 80MiB (real megabytes). What can be the reason? Card description (lshw output): description: ...
8
votes
3answers
4k views

Which tool should I trust, mii-tool and ethtool don't show me the same values

Our hosting company provides all the switching infrastructure for our servers. The private network, connected to eth2 should be GbE. Recently I've been suspecting that something is misconfigured as ...