About ashok.net.3026

ashok.net.3026 · 10-20-2011

Hi BGP Experts,I am seeing a behaviour where the as-path prepend allows the cisco router to advertise a route with as-path where the originating AS is changed after applying route-map . As per my understanding the originating AS should not be changed...

ashok.net.3026 · 10-20-2011

Hi Peter,Thanks for detailed explanation . However, This introduces a very geniune BGP Attack and as earlier pointed out by Alain that this could lead a black holing of traffic. if you consider that the "shortest path" would be a prevention mechanism...

ashok.net.3026 · 10-20-2011

Hi Alain,I do understand the implementation could be different to handle such situation. In other solution, we should first add originating AS and then add the as-path prepend which will fix this issue. On Similar notes , There must be a valid reason...

ashok.net.3026 · 10-20-2011

Hi Alain,I also have the same concern . This configuration should not be allowed in first place.I just wanted to know if there are any valid use-case where it needs to be allowed such config. if not, we should not be allowed to do such configuration...

ashok.net.3026 · 10-20-2011

Hi Vaibhava,I did see the same behaviour what you have mentioned . However if you refer rfc 4271 , it clearly mentions that when it is originating AS , we must add originating AS a right most AS . The issue is that due to such configuration , We are...

ashok.net.3026 · 10-20-2011

Hi Alain,In this case it should not be allowed to configure the different AS numbers if as-path prepend only used for the purpose of use your own AS number.I hope this clarifies my opinion to use different AS numbers.Thanks & Regards,Ashok.

Member Since	‎10-20-2011 12:35 AM
Date Last Visited	‎10-06-2017 06:01 AM
Posts	10

User Statistics

User Activity

Why as-path prepend appends as number when a route-map applied in out direction on originating AS ?

Why as-path prepend appends as number when a route-map applied i

Re: Why as-path prepend appends as number when a route-map appli

Re: Why as-path prepend appends as number when a route-map appli

Re: Why as-path prepend appends as number when a route-map appli

Re: Why as-path prepend appends as number when a route-map appli