CCNA Commands.

CCNA Basic commands. Cisco Commands. CCNA Study Material.

CCNA Commands.

These following CCNA commands almost covered the lab and theory syllabus of CCNA Exam conducted by Cisco. These following commands always helpful for the Cisco Exam and configuring and maintaining the Cisco routers. These commands are the Online study materials for Cisco conducting CCNA Exam.

CCNA Commands.

IP ROUTING

#sh ip route - To view IP routing tables created on a Cisco router.
-Static Routing- Routers are manually configured for networks that are not directly connected,
to be able to route to all networks via the next-hop interface.
Example- Let 192.168.30.0/24 be the IP of a network not directly connected
Let 192.168.20.2 be the next hop interface
(config)#ip route 192.168.30.0 255.255.255.0 192.168.20.2
-to remove static route
(config)#no ip route 192.168.30.0 255.255.255.0 192.168.20.2
-Default Routing- Used on stub networks only to send packets with remote destination
network not in the routing table to the next hop router.
(Assume IP 192.168.40.1 is not in routing table)
-first remove static route
(config)#no ip route 192.168.30.0 255.255.255.0 192.168.40.1
(config)#ip route 0.0.0.0 0.0.0.0 192.168.40.1

-RIP-A distance vector routing protocol that passes complete routing table contents to
neighbouring routers

Example- Let 192.168.10.0 & 192.168.20.0 be directly connected networks of a router
interfaces and 192.168.30.0 be non-directly connected
-first delete all static routes
(config)#no ip route 192.168.30.0 255.255.255.0 192.168.20.2
(config)#router rip
(config-router)#192.168.10.0
(config-router)#192.168.20.0
(config-router)#^z
#

Verifying RIP

1.Sh ip route
2.debug ip
-Holding Down RIP Propagation-To stop RIP update sending but allow its receipt
-say for s0/0 with ip 192.168.10.0
(config)#router rip
(config-router)#network 192.168.10.0
(config-router)#passive-interface serial 0/0
-IGRP-Also a distance routing protocol

Example- Let 192.168.10.0 & 192.168.20.0 be directly connected networks of a router
interfaces with autonomous system number of 10 and 192.168.30.0 be non-directly connected
#router igrp 10
(config-router)#network 192.168.10.0
(config-router)#network 192.168.20.0
(config-router)#^z
#
Verifying IGRP

1.sh ip route
2.sh protocols- Displays routed protocols and their interfaces
3.sh ip protocols- Displays routing protocols configured
4.debug igrp events- Displays summary of IGRP routing information running on the network
5.debug igrp transactions- Displays messages request from neighbour routers
Turning off all possible debugging
#un all
EIGRP-Uses classless routing which is subnet mask information sent with routing protocol
updates.
Example- Let 192.168.10.0 & 192.168.20.0 be directly connected networks of a router
interfaces with autonomous system number of 20 and 192.168.30.0 be non-directly connected
#router eigrp 20
(config-router)#network 192.168.10.0
(config-router)#network 192.168.20.0
(config-router)#^z
To stop EIGRP from working on an interface-no sending no receipt
(config)#router eigrp 20
(config-router)#passive-interface serial 0/0

To enable EIGRP on discontiguos networks(two different sub networks of class full network
connected by another different class full sub network)

Example- Let 172.16.0.0 & 10.0.0.0 be directly connected to a router to another remote
subnetwork of 192.168.10.0, then to enable EIGRP, we use
(config)#router eigrp 100
(config-router)#network 172.16.0.0
(config-router)#network 10.0.0.0
(config-router)#no auto-summary
N.B-The no auto-summary command should be enabled in routers that encloses such
networks.

Verifying EIGRP

1. sh ip route- Shows entire routing table
2. sh ip route eigrp- Shows only EIGRP entries in the routing table
3. ip eigrp neighbours- Shows all EIGRP neighbours
4. ip eigrp topology- Shows entries in the EIGRP topology table
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CCNA4.com
OSPF- A link-state routing protocol
Example- Let 10.0.0.0 be the network directly connected to the router upon which OSPF is to
be enabled; with ospf ID of 1 and area o
(config)#router ospf 1
(config-router)#network 10.0.0.0 0.255.255.255 area0

Loopback Interface- They are configured to be used as the routers RID to advertise the routes
and elect DR and BDR.

Example- Let the loopback iinterface be configured on interface with ip 172.16.10.1
(config)#int loopback 0
(config-if)#ip address 172.16.10.1 255.255.255.0
(config-if)#no shut
(config-if)#^z

Verifying OSPF Configuration

1. sho ip ospf- Used to display all OSPF information
2. sho ip ospf database- indicates the number of links and neighboring router ID
3. sho ip ospf interface- Displays all OSPF interface related info
4. sho ip ospf neighbour- Summarizes OSPF info about neighbours
5. sho ip protocols- Overview of all present running protocols

Verifying Loopback and RID

1. sho running-config- To verify loopback address
2. sho ip ospf database- Verifies the new RID of each router
3. sho ip ospf interface- Verifies the new RID of each router
-Initial configuration of a 1900 Switch with ip 172.16.10.16
>en
#config t
(config)#enable password level 1 kennifeh
(config)#enable password level 15kennifeh 1
(config)#enable secret kennifeh 2(when enabled no need 4 enable password)
(config)#hostname kenn 1900
(config)#ip address 172.16.10.16 255.255.255.0
(config)#ip default-gateway 172.16.10.1
(config)#int f0/1
(config-if)#description Finance_vlan (No space for 1900)
(config-if)#int f0/26
(config-if)#description Trunk_to_Biulding
(config-if)#exit
(config)#
-Initail Configuration of 2950 Switch with ip 172.16.10.17 255.255.255.0
>en
#config t
(config)#hostame kenn2950
(config)#enable password kenn
(config)#enable password kenn1(enable and enable secret password must be different)
(config)#line vty 0 15
(config-line)#login
(config-line)#password telnet
(config-line)#line con 0
(config-line)#login
(config-line)#password console
(config-line)#exit
(config)#int vlan 1
(config-if)#ip address 172.16.10.17 255.255.255.0
(config-if)#no shut
(config-if)#int f0/1
(config-if)#description sales printer(with space)
(config-if)#int f0/12
(config-if)description connection to backbone
config-if)#exit
(config)#ip default-gateway 172.16.10.1
(config)#
-Erasing Switching Configuration 1900
#delete nvram
yes
-Erasing Switching Configuration 2950
#erase startup-config
Enter

Configuring VLANS 1900

>en
#config t
(config)#vlan 2 name Cisco
(config)#vlan 3 name Microsoft
(config)#vlan 4 name Comptia
(config)#exit
verify with command sh run
-Configuring for 2950
>en
#vlan database
(vlan)#vlan 2 name Cisco
(vlan)#vlan 3 name Microsoft
(vlan)#vlan 4 name Comptia
(vlan)#apply
(vlan)#^c

verify with command sh vlan brief

Assigning Switch Ports To Vlan-1900
(config)#int e0/2
(config-if)#vlan-membership static 2
(config-if)#int e0/3
(config-if)#vlan-membership static 3
(config-if)#exit
verify with sh vlan
-Assigning Switch Ports To Vlan-2950
(config)#int f0/2
(config-if)#switchport access vlan 2
(config-if)#int f0/3
(config-t)#switchport access vlan 3
(config-if)#int f0/4
(config-if)#switchport access vlan 4
(config-if)#

verify with sh vlan brief

Configuring Trunks ports
(config)#int f0/26
(config-if)#trunk on

Configuring Trunk Ports for 2950
(config)#int f0/12
(config-if)#switchport mode trunk
(config-if)#^z
#
-To disable Trunk use- switch port mode access
-To verify Trunking use sh running config
-Configuring Inter-vlan Routing for 1900 connecting to 2600
(config)#int f0/0.1
(config-if)#encapsulation isl vlan (d number)
-Configuring Inter-vlan Routing for 2950 connecting to 2600
(config)#int f0/0.1
(config-if)#encapsulation dot1q vlan (d number)
-Configuring VTP for 1900
(config)#vtp server

(config)vtp domain kenn
(config)#vtp password kenn
-Configuring VTP for 2950
(config)#vtp mode server
(config)#vtp domain routersim
(config)#^z
verify with sh vtp status
Checking the Current Configuration Register Values
show version or show ver
Changing Configuration Register

(config)#config-register 0x101 (d default is 0x2102)
(config)#^z

Recovering Passwords

-1. Interrupt the Router Boot Sequene
ctrl+Break key (windows wont perform break key, only 95/98)
-2. Changing the configuration register
-for 2600 series router
rammon>confreg 0x2142
-for 2500
type 0 after a break and enter the command o/r 0x2142
3. Reloading the Router and Entering Privilged mode
-for 2600-type reset
-for 2500-type I
4. Viewing and changing the configuration
-copy run start
5. Resetting the configuration Register and Reloading the Router
-config t
-config-register 0x2102
-copy run start-to save
Backing up and restoring the Cisco ios
1. verifying flash memory-Ensuring flash memory has enough room
router#sh flash
2. Backing-up the ciso ios
first verify server connectivity by- Router#ping 192.168.0.120
then; router#copy flash tftp

3. Restoring or upgrading the cisco router ios
router#copy tftp flash
[confirm][ENTER]
?[ENTER]

Backing up and Restoring the Cisco configuration

1.Backing up the cisco router configuration
-copy runing config tftp
2. verifying the current configuration
-sh run
3. copying the current cofiguration to NVRAM
-copy run start
4. copying the current configuration to a TFTP server
-copy run TFTP
5. Restoring the Cisco Router Configuration
-copy TFTP run
6. Erasing the configuration
-erase startup-config
-Getting CDP timers and Holdtime information
Router#config t
Router(config)#cdp timer 90
Router(config)#cdp holdtime 240
Router(config)#^z

To turn-off CDP Completely-no cdp run
Gathering Neighbour information
kenn2509#sh cdp nei- delivers information about directly connected devices
OR kenn2509#sh cdp neighbour detail Also sh cdp entry
Gathering Interface Traffic Information

kenn2509#sh cdp traffic
-Gathering port and Interface information
kenn2509#sh cdp interface
-To turn off cdp on a router, use
no cdp enable then ^z
-Using Telnet
kenn2509#telnet 172.16.10.2
-Telnetting into multiple devices simultaneously
kenn2509#telnet 172.16.10.2
then, 2501B>{cntl+shift+6, then x}

checking Telnet connections

kenn2509#sh sessions-connections from your router to remote
-checking Telnet users
kenn2509#sh user
-closing Telnet sessions
1900switch>exit OR
kenn2509#disconnect1 (num of active networks)
-Resolving Hostname
kenn2509#config t
kenn2509(config)#ip host 2501B 172.16.10.2
kenn2509(config)#ip host 1900switch 192.168.0.148
kenn2509(config)#^z
To remove a hostname from a table, use
RouterA(config)#no ip host routerB

Using DNS to resolve names

#config t
(config)#ip domain-lookup (usually turned on by default)
(config)#ip name-server 192.168.0.70 (ip of an assumed DNS set)
(config)#ip domain-name kenn.com (Appends the domain name to a host)
(config)#^z
-Check Network Connectivity
use ping command
#ping kenn2509
-Using Traceroute command
#trace 2501B
-Creating a Standard Access Lists (1-99 or 1,300-1,999)
(config)#access-list 10 deny 172.16.30.2 (using the ip as a test)
-Controlling vty(Telnet) sessions
(config)#access-list 50 permit 172.16.30.2
(config)#line vty 0 4
(config-line)#access-class 50 in
-Creating Extended Access-lists (100 to 199) OR (2000 to 2699)
(config)#access-list 110 deny tcp any host 172.16.30.2 eq 23 log
(config)#access-list 110 permit ip any any
(config)#int f0/0
(config-if)#ip access-group 110 in
(config-if)#ip access-group 110 out

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