Thursday, November 5, 2015

BGP Route Reflector - Routing advertisements rules

In order to avoid a looping route, the route reflector follows the 3 rules below:

1/ routes learned from an eBGP peers can be announced to eBGP peers, clients and non-clients.

2/ routes learned from a client can be announced to eBGP peers, others clients and non-clients.

3/ routes learned from a non-client can be announced to eBGP peers, clients and they cannot be sent to a non-clients.

Wednesday, November 4, 2015

Track an IP on your Network

Who has never received the following question from a colleague:
- Hey, the network guy, could you find where is this laptop for me ? I have only his IP address.

To resolve this, you start to follow the IP address by looking in the arp and mac-address table of your switchs, routers and firewall. I have finished this boring job by using the following open source tool:
http://netdbtracking.sourceforge.net/

Developpers have alreay preconfigured a VM:
http://sourceforge.net/projects/netdbtracking/files/vmware/

After 30 minutes of the VM installation and some hours (depending of the size of your network) of configuration to enter your different equipment, you can provide a webtools reachable from everybody to track an IP.

You will find below some examples of host configuration.


  • HP Procurve (Layer 3)

hostname,devtype=procurvehpv2, arp


  • HP Procurve (Layer 2):

On this example, I skipped uplinks interfaces (45 and 47). I have also limited to 2 mac address by interface.
hostname,devtype=procurvehpv2,skip_port=45,skip_port=47,use_trunks,max_macs=2