auto-summary is used by default by Distance Vector routers and happens at a major network transition. If you have a router that have the DV IGP running on interfaces with ip addresses belonging to two different major networks (example 10.0.0.0/8 and 172.16.0.0/16) when preparing the updates to send out an interface that is part of major network 2 it will send out the classful major network instead of the known subnets in major network 1 and viceversa out of an interface thar is part of major network 1 it will send out a single entry major_net2.
This behaviour can be a problem if you have used subnets of a major network on different remote sites (for example you use some 10.x.y.0 prefixes on the client lan and you use on the wan links subnets in class 172.16.x.y) and you want from the central site to know the details for correct forwarding.
RIPv2 and EIGRP allows to disable auto-summary feature.
Old protocols like RIPv1 and IGRP have the problem that they do not send the prefix mask in their updates.
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.