One of the basic configurations when setting up a Cisco Router or a Cisco Switch is setting the passwords. This includes, setting the passwords for the Console, Telnet/SSH and the Enable (Enable Secret)
The following procedure will help starters set up passwords in Cisco Routers and Switches running Cisco IOS.
When we configure a routing protocol on Cisco IOS Routers, it is important to consider preventing Routing updates sent on interfaces that are not required to (say a LAN where there is no other router in the segment to receive any updates). This ensure we are not passing updates that could cause network issues. Needless to say, the network becomes less chatty and can make life more easy when sniffing or spanning for network troubleshooting.
In Cisco IOS we can globally or selectively prevent interfaces on which we do not want routing updates to be sent. Ideally, it would be better that we do this globally and then selectively allow interfaces that can send routing updates.
Cisco SPAN port is a SwitchPort ANalyzer on the cisco catalyst that allows to select and span or copy traffic from one or more source switchports or source VLANs onto one or more destination ports. The destination port(s) runs a sniffing or a packet capture program like Ethereal, Wireshark or TCPDump.
Cisco IOS support Local SPAN and Remote SPAN (RSPAN). (more…)