A little bit of wisdom
*** NOTE: this was written several years ago – but may still be useful *** VLANS Increase security and ease administration and relocation. Break up broadcast domains. VLANS work at layer 2 and 3 of OSI model. Communication between VLANs uses layer 3 routing. 3 ways of assigning a switched port to VLANs: Port-Centric – […]
** note – this is several years old now – but much of it is still useful ** Cisco CCNA Certification Study Guide Ctrl+Shift+6 then X – Allows you to open more than one telnet session. Only the Hardware addresses change when packets go through routers. Half duplex Ethernet – One station can only send […]
CISCO – Blocking broadcast traffic. We’ve had some requests for examples of how to filter broadcast traffic. As with a lot of things in the computer world, “there is more than one way to do it.” If your network is composed *only* of /24 allocations (ie you’re not supernetting or subnetting anywhere on class C’s, […]
How to enable debugging on a Cisco router. Execute the command terminal monitor
Forcing Duplex at startup – Linux Note: This article is rather old and remains for historical purposes only. alias eth0 e100 options e100 e100_speed_duplex=4 Further information: http://www.scyld.com/diag_index.html
AS number. AS = Autonomous System Number From Wikipedia Border Gateway Protocol (BGP) is a standardized exterior gateway protocol designed to exchange routing and reachability information between autonomous systems (AS) on the Internet.[1] The protocol is often classified as a path vector protocol, but is sometimes also classed as a distance-vector routing protocol. The Border […]
Private Address Range (ipv4) 10.0.0.0 – 10.255.255.255 (10/8 prefix) 172.16.0.0 – 172.31.255.255 (172.16/12 prefix) (/12=255.240.0.0) 192.168.0.0 – 192.168.255.255 (192.168/16 prefix)
Network Revision – TCP/IP etc. This module is (mostly) taken by two types of people – those who have done a networking course and those who will soon. (There is also sometimes a minority who haven’t and won’t – don’t worry if this is you.) Those of you familiar with networking to some extent will […]
Network / USB / SCSI – speeds. If like me you’ve started to get a little lost in all the various network, cabling and WiFi options you might be interested in this short comparison of the various cable types. Cable Type – Speed USB 1: 1.5 Mb/s – 12 Mbs USB 2: 480 Mb/s Firewire […]
100Base-T Cabling Guidelines This section describes 100Base-T cabling guidelines and some common configurations for Catalyst 2800 modules. The following cabling guidelines apply to a 100Base-T network: The maximum length for an Unshielded Twisted Pair (UTP) cable segment is 100 meters. Any cable segment longer than 100 meters must be fiber. A 100Base-T repeater is equivalent […]
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