The first loops the traffic and the other loops the routing table entries themselves.
A traffic loop is easy to do.
Just put in the same static route in 2 routers and point them to each other.
If you have router A with ip address 192.168.1.1 and router b wiht ip address 192.168.1.2
In router A put in
IP route 10.10.10.0 255.255.255.0 192.168.1.2
in router b put in
ip route 10.10.10.0 255.255.255.0 192.168.1.1
now ping 10.10.10.1 from either router.
A routing loop of the routing table itself is very complex to simulate and very hard to fix.
Basically it is caused by route redistribution on multiple routers. A single routing protocol is smart enough to know that I do not want to learn a route that I just sent to another router. When you convert routes from one routing protocol to another some of this information is lost.
For this second kind of loop you need a good understatnding of administative distance. I do not have a simple example of how to do this since it in most cases will require 3 or 4 routers to get loop that will be of any interest to look at.
A routing loop comes from error in your routing configuration. For example if you have two routers connected together A and B and that A beleives that subnet X is reachable via B and B beleives that the subnet X is reachable via A, a packet destinated to X will loop between A and B until its TTL reaches 0.
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.