Adding ACL on CATOS (6500)

Console> (enable) set ip permit 172.16.0.0 255.255.0.0 telnet
172.16.0.0 with mask 255.255.0.0 added to telnet permit list.

Console> (enable) set ip permit 172.20.52.42 255.255.255.224 snmp
172.20.52.42 with mask 255.255.255.224 added to snmp permit list.

To check:
Console> (enable) sh ip permit

Adding Repositories on CentOS

Adding DAG Repo:

#cd /etc/yum.repos.d
#vi dag.repo

Fill-in the following lines and save it.

[dag]
name=Dag RPM Repository for Red Hat Enterprise Linux baseurl=http://apt.sw.be/redhat/el$releasever/en/$basearch/dag
gpgcheck=1
enabled=1

Issue this ;

# rpm –import http://dag.wieers.com/rpm/packages/RPM-GPG-KEY.dag.txt


Try to install using yum.

Neat huh...

Cisco Discovery Protocol

Cisco Discovery Protocol

Router#show cdp	Displays global CDP information (such as timers)
Router#show cdp neighbors	Displays information about neighbors
Router#show cdp neighbors detail	Displays more detail about neighbor device
Router#show cdp entry word	Displays information about device named word
Router#show cdp entry *	Displays information about all devices
Router#show cdp interface	Displays info about interfaces that have CDP running
Router#show cdp interface x	Displays info about specific interface x running CDP
Router#show cdp traffic	Displays traffic infopackets in/out/version
Router(config)#cdp holdtime x	Changes length of time to keep CDP packets
Router(config)#cdp timer x	Changes how often CDP updates are sent
Router(config)#cdp run	Enables CDP globally (on by default)
Router(config)#no cdp run	Turns off CDP globally
Router(config-if)#cdp enable	Enables CDP on a specific interface
Router(config-if)#no cdp enable	Turns off CDP on a specific interface
Router#clear cdp counters	Resets traffic counters to 0
Router#clear cdp table	Deletes the CDP table
Router#debug cdp adjacency	Monitors CDP neighbor information
Router#debug cdp events	Monitors all CDP events
Router#debug cdp ip	Monitors CDP events specifically for IP
Router#debug cdp packets	Monitors CDP packet-related information

Caution:

Although CDP is an excellent source of information to you the network administrator, is it a potential security risk if a hacker gains access to one of your systems. The information that you gain through CDP is also gained by the hacker.

After you have used CDP to gather your information in a production environment, turn it off to thwart any bad people from using it for no good.