Virtual Networking




Home | Poetry | Free SMS | F Services | Engineering | Facebook |Videos | About Us


Tuesday, 12 July 2016

CCNA commands and explanation

IP ROUTING

#sh ip route - To view IP routing tables created on a Cisco router.

v  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

v  To remove static route

(config)#no ip route 192.168.30.0 255.255.255.0 192.168.20.2

v  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)

v  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

v  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

v  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

v Verifying RIP   
     1.Sh ip route
     2.debug ip

v  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
v  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


v  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

v  Turning off all possible debugging #un all

v  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

v  To stop EIGRP from working on an interface-no sending no receipt (config)#router eigrp 20

(config-router)#passive-interface serial 0/0

v  To enable EIGRP on discontiguos networks(two different subnetworks of classfull network connected by another different classful subnetwork)

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


v  N.B-The no auto-summary command sholuld be enabled in routers that encloses such networks.

v  Verifying EIGRP 
1.1.   sh ip route- Shows entire routing table
1.2.   sh ip route eigrp- Shows only EIGRP entries in the routing table
1.3.   ip eigrp neighbours- Shows all EIGRP neighbours
1.4.   ip eigrp topology- Shows entries in the EIGRP topology table


v  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

v  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

v  Verifying OSPF Configuration

1.1.   sho ip ospf- Used to display all OSPF information
1.2.   sho ip ospf database- indicates the number of links and neighboring router ID
1.3.   sho ip ospf interface- Displays all OSPF interface related info
1.4.   sho ip ospf neighbour- Summarizes OSPF info about neighbours
1.5.   sho ip protocols- Overview of all present running protocols

v  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

v  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 15 kennifeh 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

v  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)
v  Erasing Switching Configuration 1900

#delete nvram yes

v  Erasing Switching Configuration 2950

#erase startup-config Enter

v  Configuring VLANS 1900

>en #config t
(config)#vlan 2 name Cisco
(config)#vlan 3 name Microsoft
(config)#vlan 4 name Comptia
(config)#exit

v  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

v  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

v  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

v  Configuring Trunks ports

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

v  Configuring Trunk Ports for 2950

(config)#int f0/12
(config-if)#switchport mode trunk
(config-if)#^z
v  To disable Trunk use- switchport mode access
v  To verify Trunking use sh running config
v  Configuring Inter-vlan Routing for 1900 connecting to 2600

(config)#int f0/0.1
(config-if)#encapsulation isl vlan (d number)
v  Configuring Inter-vlan Routing for 2950 connecting to 2600
(config)#int f0/0.1
(config-if)#encapsulation dot1q vlan (d number)


v  Configuring VTP for 1900
(config)#vtp server
(config)vtp domain kenn
(config)#vtp password kenn

v  Configuring VTP for 2950

(config)#vtp mode server
(config)#vtp domain routersim
(config)#^z

v  Verify with sh vtp status
v  Checking the Current Configuration Register Values
v  Show version or show ver
v  Changing Configuration Register

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

v  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
3. for 2500
type 0 after a break and enter the command o/r 0x2142
4. Reloading the Router and Entering Privilged mode -for 2600-type reset

5. Viewing and changing the    configuration -copy run start


6. Resetting the configuration Register and Reloading the    Router -config t

v  Backing up and restoring the Cisco ios
 verifying flash memory-Ensuring flash memory has enough

room router#sh flash



v  Backing-up the ciso ios

first verify server connectivity by-
Router#ping 192.168.0.120
      then;
router#copy flash tftp
v  Restoring or upgrading the cisco router

ios router#copy tftp flash

[confirm][ENTER]
?[ENTER]

v  Backing up and Restoring the Cisco configuration

Ø  Backing up the cisco router configuration -copy runing config tftp
Ø  Verifying the current configuration -sh run
Ø  copying the current cofiguration to NVRAM -copy run start
Ø  copying the current configuration to a TFTP server -copy run TFTP
Ø  Restoring the Cisco Router Configuration

Ø  copy TFTP run
Ø  Erasing the configuration -erase startup-config

v  Getting CDP timers and Holdtime

information Router#config t

Router(config)#cdp timer 90
Router(config)#cdp holdtime 240
Router(config)#^z

v  To turn-off CDP Completely-no cdp run
v  Gathering Neighbour information

kenn2509#sh cdp nei
Ø  delivers information about directly connected devices OR kenn2509#sh cdp neighbour
Ø  detail Also sh cdp entry


v  Gathering Interface Traffic Information kenn2509#sh cdp traffic
v  Gathering port and Interface
 information kenn2509#sh cdp interface

v  To turn off cdp on a router, use no cdp enable then ^z

v  Using Telnet
       kenn2509#telnet 172.16.10.2

v  Telnetting into multiple devices
simultaneously kenn2509#telnet 172.16.10.2

     then,  2501B>{cntl+shift+6, then x}
v  Checking Telnet connections

kenn2509#sh sessions-connections from your router to remote

v  Checking Telnet users
kenn2509#sh user

v  Closing Telnet sessions
1900switch>exit OR

kenn2509#disconnect1 (num of active networks)

v  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

v  To remove a hostname from a table, use
RouterA(config)#no ip host routerB

v  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

v  Check Network Connectivity use ping command

#ping kenn2509

v  Using Traceroute command #trace 2501B

v  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)

v  Controlling vty(Telnet) sessions
(config)#access-list 50 permit 172.16.30.2
(config)#line vty 0 4
(config-line)#access-class 50 in


v  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)#ipaccess-group 110 out



No comments:

Post a Comment