Most Popular
1500 questions
11
votes
6 answers
Weather map and monitoring for network usage
What tools are able to provide an almost real time weather map of usage and average traffic per timeframe going over the different links?
What are some ways or solutions to actively monitor my network and provide alerts on heavy network usage over a…
Lucas Kauffman
- 4,171
- 5
- 29
- 51
11
votes
2 answers
catalyst 3750x - jumbo frames on svi
I've encountered a problem on a cisco ws-c3750x-48ts-s where jumbo-frames won't cross a trunk-connection between a vwmare esx-host and the switch.
The access ports in the same vlan don't experience any problems.
I suspect that the problem lies…
VincentG
- 111
- 2
- 4
11
votes
2 answers
End-to-End FCoE
I have been evaluating converged storage/data networking for some time. It seems that the design pitched by vendors is a bridging of the Fiber Channel (FC) and Ethernet domains. I always come away questioning if this is just some interim step…
Dennis Olvany
- 2,435
- 1
- 17
- 34
11
votes
1 answer
Plexiglass and 2.4GHz wifi signal
I have very simple question:
If device which uses regular WiFi (2.4 GHz) connection (i.e. USB receiver for wireless mouse or mobile phone) is put into plexiglass case, would that lower connection quality?
I've heard a lot of contradiction claims…
10robinho
- 283
- 1
- 3
- 6
11
votes
2 answers
How did I break (half of) my network?
I'm looking for some post-event advice so this event doesn't happen again.
We have a network core of two Cisco 4500x switches, configured for VSS redundancy. From those, we have iSCSI devices, our HP bladecenter for our vSphere, plus aggregated…
mfinni
- 243
- 1
- 9
11
votes
2 answers
How does nmap distinguish closed ports from filtered ports
Let's suppose we are doing a TCP connect scan.
a nmap scan on google returns the following output :
PORT STATE SERVICE
80/tcp open http
443/tcp open https
However, if I try to open a socket with netcat or telnet on google.com on the port 12…
Intrepidd
- 213
- 2
- 6
11
votes
1 answer
How to create a DOCSIS network
I have two old cable modems I used to use with my ISP, they are no longer used because I upgraded my service to include VOIP.
I was wondering what would be involved to create essentially a microcosm of the big cable companies DOCSIS networks, using…
lightbord
- 213
- 1
- 4
11
votes
4 answers
Is there an automatable way to backup the configuration from a WLC 2504 controller?
I am looking for a way to backup the controller configuration file via an automatic process. I've seen links to the web interface which appears to do a one-time tftp copy of the config to a remote host, however I'm looking for a way to schedule the…
Peter Grace
- 705
- 1
- 8
- 22
11
votes
3 answers
Why do LANs use MAC addressing instead of IP addressing?
Why do LANs use MAC addressing instead of IP addressing?
In other words, why can't a network just assign an IP address to a local area network device and send the data to that, instead of the MAC address? MAC addresses seem quite redundant without…
Oliver K
- 397
- 1
- 5
- 12
11
votes
4 answers
What's the point of auto-sensing 10/100 Mbit/s Ethernet?
According to the notes I'm reading:
10/100 Mbit/s Ethernet refers to the standard that can autosense which speed it needs to run between speeds of 10 Mbit/s or 100 Mbit/s.
Why would autosensing be required? Wouldn't it be best to result to…
Oliver K
- 397
- 1
- 5
- 12
11
votes
1 answer
Cisco IOS programming, automation, and information
I'm confused about Cisco IOS, and I have some question about that.
Cisco IOS is used in routers and other devices.
Is it possible to write code (like PHP) for that?
If it's possible, what language can I use?
The thing that confuses me is not how to…
Pooya Mahmoodi
- 113
- 5
11
votes
1 answer
Traffic generation from Cisco IOS device to prove WAN circuit
In essence I want to know if there is any way that we can use extended ping or any other command variants to prove to the customer that that the circuit is able to achieve the minimum CIR. The CE routers are Cisco ISRs 881,19x1 & 29x1 running 15.1,…
DrBru
- 1,619
- 3
- 16
- 33
11
votes
1 answer
Cisco Catalyst 3750/3560 SYN FLOOD protection
How could one mitigate SYN FLOOD DOS on Catalyst 3750/3560 as it has no control plane protection?
romuald_geo
- 113
- 5
11
votes
3 answers
What is the proper name for hexadecimal like standard notation of an IPv6 address?
RFCs such as 5952 - "A Recommendation for IPv6 Address Text Representation" and
2373 - "IP Version 6 Addressing Architecture" each outline the commonly used hexadecimal and colon based notation that is typically used for representing an IPv6…
rheone
- 212
- 1
- 8
11
votes
4 answers
Migration from IPv4 to IPv6 strategies
As everyone is aware we are out of IPv4 addresses and soon (if not already) we shall be moving on to IPv6. What are some good strategies and practices to migrate a complete IPv4 network onto IPv6?
Lucas Kauffman
- 4,171
- 5
- 29
- 51