Q. How does BGP behave differently with auto-summary enabled or disabled?
A. When auto-summary is enabled, it summarizes the locally originated BGP networks to their classfull boundaries. (Auto-summary is enabled by default in BGP). When auto-summary is disabled, the routes introduced locally into the BGP table are not summarized to their classfull boundaries. When a subnet exists in the routing table and the following three conditions are satisfied, then any subnet of that classfull network in the local routing table will prompt BGP to install the classfull network into the BGP table.
Classfull network statement for a network in the routing table
Classfull mask on that network statement
For example, if the subnet in the routing table is 22.214.171.124 mask 255.255.255.0, and we configure network 126.96.36.199 under the router bgp command, and auto-summary is enabled, BGP will introduce the classfull network 188.8.131.52 mask 255.0.0.0 in the BGP table.
If these three conditions are not all met, then BGP will not install any entry in the BGP table unless there is an exact match in the local routing table.
Note: If the AS doing BGP does not own the complete classfull network, we suggest disabling auto-summary using the no auto-summary command under router bgp.
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.