How to backup Linux OS using “dd” Command
“dd” command can be really handy when it comes to taking an Operating System backup to clone the disk the OS is installed on. Here are few examples of using dd command for taking OS backup. NOTE: The target drive must be either of identical size to the drive being cloned or larger. The dd […]
Linux TCP_RTO_MIN, TCP_RTO_MAX and the tcp_retries2 sysctl
TCP retransmits an unacknowledged packet up to tcp_retries2 sysctl setting times (defaults to 15) using an exponential backoff timeout for which each retransmission timeout is between TCP_RTO_MIN (200 ms) and TCP_RTO_MAX (120 seconds). Once the 15th retry expires (by default), the TCP stack will notify the layers above (ie. app) of a broken connection. The […]
VIO Server Howto
1. Run IOS commands as root According to IBM you should never work as root on VIO servers. However, if you login as user padmin and type oem_setup_env you get the root credentials (without even been asked for a password). By default the ioscli commands are not available for the root user. All ioscli commands […]
25 powershell command
1. Navigate the Windows Registry like the file system: cd hkcu: 2. Search recursively for a certain string within files: dir –r | select string “searchforthis” 3. Find the five processes using the most memory: ps | sort –p ws | select –last 5 4. Cycle a service (stop, and then restart it) like DHCP: […]
Some practical Cisco switch command
Some useful cisco switch command Show command on switch Nepalitservice#show version Displays software and hardware information Nepalitservice#show running-config Displays currently running configuration in DRAM Nepalitservice#show start Displays configuration in NVRAM which will be loaded after reboot Nepalitservice#show flash: Displays Flash memory information Nepalitservice#show boot Displays boot path and image Nepalitservice#show clock Displays the system clock […]
Enabling SSH on a Cisco Router for Secure Remote Login
Ensure you have a hostname configured on your router:Router#conf t Router(config)#hostname router23 You must also configure a domain name:Router(config)#ip domain-name jpt Generate an RSA keypair with a key length of 1024 bits using the following sequence of commands:router(config)#router(config)#crypto key generate rsa The name for the keys will be: routername.soundtraining.class (where routername is your router’s hostname) […]
Planet vlan
Planet Switch Configuration Step 1: Log into the Planet SwitchPlanet switch default IP address is 192.168.0.100. Default password is “admin”Once you have logged into the switch you can change the default IP address to match the IP subnet for LAN1. Here we have used the IP address 192.168.10.100. Step 2: Configure VLAN MembershipGo to VLAN […]
switch basic
TestSwitch#show version [Displays software and hardware information]TestSwitch#show running-config [Displays currently running configuration in DRAM]TestSwitch#show start [Displays configuration in NVRAM which will be loaded after reboot]TestSwitch#show flash: [Displays Flash memory information]TestSwitch#show boot [Displays boot path and image]TestSwitch#show clock [Displays the system clock]TestSwitch#show interfaces [Displays all interfaces configuration and status of line]TestSwitch#show vlan [Displays vlan number, name, […]
asa basic
ciscoasa> enable ciscoasa# configure terminal ciscoasa(config)# ciscoasa# show running-config ciscoasa# show startup-config ciscoasa# copy run start ciscoasa# write memory ciscoasa# copy tftp flash ciscoasa#config term ciscoasa(config)# boot system flash:/asa911-k8.bin ciscoasa(config)# enable password Gh4w7$-s39fg#(! ciscoasa(config)#username ciscoadmin password adminpassword privilege 15 ciscoasa(config)# hostname DATA-CENTER-FW ciscoasa(config)# crypto key generate rsa modulus 2048 ciscoasa(config)#aaa authentication ssh console LOCAL ciscoasa(config)#username […]
How to configure SPAN and RSPAN in Cisco Catalyst switches
span Switch#conf tSwitch(config)#monitor session 1 source interface Gi0/1 rxSwitch(config)#monitor session 1 destination interface Gi0/2Switch(config)#end Rspan (Source switch) Switch1#conf tSwitch1(config)#vlan 30Switch1(config-vlan)#name RSPAN-VlanSwitch1(config-vlan)#remote-spanSwitch1(config-vlan)#exitSwitch1(config)#monitor session 1 source interface Gi0/1 rxSwitch1(config)#monitor session 1 destination remote vlan 30Switch1(config)#end Allow vlan id 30 on the trunk port Gi0/2 Switch1#sh run int g0/2switchport trunk encapsulation dot1qswitchport trunk allowed vlan 10,20,30switchport […]