Friday, December 19, 2014

Configuring IPv6 on Cisco Switch 3750V2

IPv6 addressing and unicast routing are disable by default on Cisco switches, all  those features has to be enabled before we can configure them.
Here is default IPv6 configuration:
Feature
Default Setting
SDM template
Advance desktop. Default is advanced template
IPv6 routing
Disabled globally and on all interfaces
CEFv6 or dCEFv6
Disabled (IPv4 CEF and dCEF are enabled by default)
Note   
When IPv6 routing is enabled, CEFv6 and dCEF6 are automatically enabled.
IPv6 addresses
None configured


No, SDM is not Security Device Manager, this actually stand for Switch Database Manager.
SDM templates are used to configure system resources in the switch to optimize support for specific features and to balance resources, in this case we are going to use for IPv6. For more details about SDM template go to: Cisco doc about SDM Template

Friday, October 3, 2014

HSRP Configuration

This going to be straightforward configuration. But at beginning lets see some default values for HSRP and states of device with enabled HSRP.

Default HSRP Configuration

Feature
Default Setting
HSRP groups
None configured
Standby group number
0
Standby MAC address
System assigned as: 0000.0c07.acXX, where XX is the HSRP group number.
The HSRP Version 2 uses a new MAC address range 0000.0C9F.F000 to 0000.0C9F.FFFF. Your MAC address corresponds to the standby group number
Standby priority
100
Standby delay
0 (no delay)
Standby track interface priority
10
Standby hello time
3 seconds
Standby holdtime
10 seconds

HSRP States

When in operation, HSRP devices are configured into one of many states:

  • Active – This is the state of the device that is actively forwarding traffic.
  • Init or Disabled – This is the state of a device that is not yet ready or able to participate in HSRP.
  • Learn – This is the state of a device that has not yet determined the virtual IP address and has not yet seen a hello message from an active device.
  • Listen – This is the state of a device that is receiving hello messages.
  • Speak – This is the state of a device that is sending and receiving hello messages.
  • Standby – This is the state of a device that is prepared to take over the traffic forwarding duties from the active device.

Sunday, December 1, 2013

BGP Route Reflector – Juniper

Configuring IBGP can be very painful because every router in network has to have peering session that must be manually configured and full mash is a must for IBGP.
There is a formula that you can calculate how many sessions is needed in network. Let’s say that you have 10 routers and that you have configure peer sessions with all routers in AS.
N*(N-1)/2
N represent total number of routers in AS. For example let’s say that we have 10 routers, we come up to 45 sessions that must be configured.
There is tool that help as to reduce number of needed sessions in network and that is route reflector.
Route reflection allows creating peer relationships only with designated route reflector router.
In that case you will need only IBGP peer session between route reflector clients and selected route reflector router.
Router reflector and router reflector clients must be in the same cluster.
You can have more than one router reflector router under same AS, also to enable connectivity for router reflector client and nonclient routers under AS, route reflector router must be full meshed with all routers in AS.






Saturday, November 9, 2013

BFD Bidirectional Forwarding Protocol - Juniper



Under Junos there is several HA (High Availability) features, like NSR, Graceful Restart, Graceful RE Switchover and of course BFD. I’ll be briefly write about it and I’ll configure it on two Juniper routers under OSPF process.
What the BFD is actually?
Bidirectional Forwarding Protocol is protocol that is used to detect faults between two forwarding engines connected by link.
BFD is vendor and protocol independent and operates on top of any data protocol (network layer, link layer, tunnels, etc.)  It is very light weight on resources (CPU, Memory) in compered with other protocol faults mechanism, such Hello under OSPF which is very slow compared with BFD.
The benefits of BFD are that provide a single method for managing protocol timers.

Supported protocols are:

  • OSPF
  • Static
  • IS-IS
  • RIP
  • iBGP
  • EBGP
  • RSVP

Saturday, July 27, 2013

NTP Cisco - Juniper MD5 Authentication



In this example I'm going to configure Cisco router to by NTP server and the source for his time will be local configured time, best practice is to use more then one NTP server and use GPS Network Time Server (hardware or software)

 
R1#show clock
*00:06:25.899 UTC Fri Mar 1 2002
R1#clock set 21:51:50 22 july 2013  
- Use clock set command

SolarWinds SFTP & SCP Server Running Problem



I download and installed the SolarWinds SFTP & SCP Server, you can find lots of free network tools at theirs site. 
For free tolls follow the link http://www.solarwinds.com/downloads/
But I had to point to the problem that I have lunching the SFTP & SCP server. When I run the application everything looks just fine, except the service is not running and cannot be started.

See pictures below:




Friday, July 12, 2013

Oracle VM And Windows Server 2012 Nic Problem



I installed Windows Server 2012 for testing in Oracle VM, and during installation I used default configuration for VM. When I logged on and try to configure network settings there wasn't an network adapter at all.


Thursday, July 11, 2013

Backup Configuration Using Kron Schedule



You want to make sure your router automatically saves its configuration on scheduled time? For that purpose you can use kron command on router or switch.

But (yes, there is a but :)) , first you have to configure accurate time on router, to do that use clock set or use ntp server command.

In this lab I'm using TFTP server (tftpd32) for backing up my config, you can use FTP or SCP and kron command to automatically backup configuration.


Here you can download TFTP, SFTP and SCP servers without any fees. 


After setting the clock, disable pop-up questions when using copy command, those questions are appears beside you supply the complete source and destination file name in the command line, the IOS  will still ask you a question about ip address of TFTP server and file name destination.

To solve the problem use file prompt quit command (the default value is noisy), after that you can start configuring kron scheduler.




Step 1.
HLabR1(config)#kron policy-list SAVECONFIG
HLabR1(config-kron-policy)#cli copy running-config tftp://10.2.0.2/config
HLabR1(config-kron-policy)#exit
HLabR1(config)#kron occurrence SAVE at 21:51 Sun recurring
HLabR1(config)#policy-list SAVECONFIG


Step 2.

Use debug kron all to see what  going to happen at scheduled time.



Jul  7 21:51:16.656: Kron CLI return 0'


**CLI 'copy running-config tftp://10.2.0.2/config':

!!1253 bytes copied in 3.268 secs (383 bytes/sec)'

Jul  7 21:51:16.664: Major 4, Minor 7

Jul  7 21:51:16.664: Respond to end of CLI Process






Use show kron schedule command to see when will run again.