Best Rated threads in Ethernet LANshow all threads

Subject Author Posted Replies
looking for pointers to chapter and verse on TEST frames
I'm mucking about with TEST frames - specifically the Linux implementation of the HP-UX linkloop command (and the linkloop_reply code of the Linux implementation, since Linux's networking does not...
9 years ago 1
Used cisco PVDM voice modules in stock,for sale!
I have following used original cisco swithes for sale: PVDM-256K-4 PVDM-256K-8 PVDM2-8 PVDM2-16 PVDM2-32 PVDM2-48 PVDM2-64 PVDM2-24DM PVDM3-16 PVDM3-32 PVDM3-64 PVDM3-128 PVDM3-256 Please contact me...
10 years ago
10HD vs. 100FD
Hello, 1) suppose two ports with the settings from the subject line attempt to communicate. I can't find in the 802.3 standard description of the exact behavior in such situation (obviously...
11 years ago 2
STP - bridge ID
Hello I'm reading the STP defined by 802.1d and can't understand one thing. All bridges are is uniquely identified by 64-bit long IDs, that in fact is a concatenation of a globally-unique 48-bit...
12 years ago 3
How to test Ring such as EAPS or RSTP recovery time?
Does anyone know how to test Ring or RSTP recovery time? Any tools I can use? Extreme networks declare the EAPS recovery time is 50ms. Thanks alot, st without more information on exactly what you want...
13 years ago 6
Utilities to Test Gigabit Ethernet
We are putting in gigabit ethernet. In trying to test the speed of the links in individual rooms, it quickly became apparent that we are bottlenecked on things like the speed of the hard drive that...
15 years ago 5
Linksys SRW224P switch? Fan Noise?
Anyone else have one of the above switches? Very nice feature set, but the fans are driving me out of the room. Anyone know how to disassemble it? I gotta do something about those fans... Thanks! Do...
16 years ago 10
Flow control frames: will I see them with tcpdump?
Greetings, I'm troubleshooting an application problem in which I think that Ethernet flow control may be a contributing factor. I think my switch may be sending PAUSE messages to particularly...
16 years ago 3
Can we daisy-chain computers together in Ethernet?
Let's say we have four computers that we want to network together. Of course, we can get a four-port hub and run an Ethernet cable from each individual computer to the hub. I wonder, though, if it's...
14 years ago 6
difference between Repeater,hub,bridge, switch,router, gateway
Hi all as far as i understand the difference between Repeater,hub,bridge, switch,router, gateway are as follows , how correct is my understanding ? Repeater Forwards every frame it receives it is a...
13 years ago 3
Ethernet packet size and QinQ standard?
A normative question: AS we all know, ethernet has a max packet size of 1514 bytes: 14 bytes header (dst + src + len/type), plus 1500 bytes data. For 802.1Q tagging, the spec was changed to allow a...
12 years ago 4
Ethernet switch flooding packets?
Hi All, I did a WireShark packet trace this evening on the network. I was surprised to see quite a few packets that weren't meant for me. Naturally I saw packets from my PC to the network, some...
13 years ago 11
100BASE-TX Scrambler Problem
For 100BASE-TX, the scrambler is defined with 18 lines of Verilog code. One could use some different circuit as long as it acts exactly the same as this. That code I include below. If you will refer...
13 years ago 5
rack switch ports on back
I am looking for a gigabit ethernet switch for a rack mount unit. For some reason most of the rack mount switches I see have the ethernet connections on the front. Not sure why that is as how many...
15 years ago 4
Does wireshark have the ability to edit and send packet?? Any other software have???
Hi~ Does wireshark or ethereal have the ability to edit and send packet???? I tried to do this,but it seems not have this function. I found a software "Packetyzer" can do this,but it have something...
15 years ago 1
Soft Ethernet BER Tester Tool
I am seeking a means of performing basic 10/100 bit error rate testing using a Win XP laptop w/ integrated NIC. Essentially I am looking for a software application to run on the laptiop that can...
15 years ago 2
How does Allied Telesis CentreCOM TM AT-210T and AT-210TS Micro Transceiver work
I recently bought a big box of surplus computer parts at our universities surplus auction for $10.00. It consisted mostly of sound cards and video cards, a couple of external modems, mice,keyboards,...
11 years ago 7
How to open the hood on this D-Link Ethernet switch?
Dear everyone, apologies for a question that's more hardware-related than networking related... I have a D-Link DGS-1216T Ethernet switch, in a 19"/1U chassis - and I'd like to remove the lid off that...
13 years ago 3
MII preamble size
IEEE 802.3 clause 22 talks about the Media Independent Interface (MII). 22.2.3 says, "Data frames transmitted through the MII shall have the frame format shown in Figure 22-10." Figure 22-10 looks a...
14 years ago 15
Generate packet with bad CRC
Hi, Does someone know if there's a way to send ethernet packet with bad CRC, with a fiber optic card? And if it is also possible to count them on a fiber optic card? it seems that "ethtool -S eth0"...
14 years ago 3