If we really want bgp for idiots, perhaps a checkbox for "make this (slightly,more,greatly) less preferred for incoming traffic" would do the job :)
Then again, perhaps people who want the results of their local configuration distributed to the ends of the earth should at least read a book or two... -Dorn On Fri, Feb 20, 2009 at 10:35 AM, Ivan Pepelnjak <ivan.pepeln...@zaplana.net > wrote: > >From the end-user perspective, it makes sense to make the "prepend" > parameter an integer. The only thing an end-user really needs is routing > policy (primary/backup selection) and sometimes AS path prepending is the > only solution. Allowing them to insert third-party AS numbers into the AS > path increases their confusion (assuming they were never exposed to Cisco > IOS). Obviously, the number of prepends has to be limited to something > sensible (10 seems a good number, and it looks like Mikrotik has > implemented > that restriction). > > The "set as-path prepend last-as" is a completely different story; it's > used > to do proxy prepending for your customers. > > Ivan Pepelnjak > http://blog.ioshints.info > > > -----Original Message----- > > From: Mikael Abrahamsson [mailto:swm...@swm.pp.se] > > Sent: Friday, February 20, 2009 3:06 PM > > To: nanog@nanog.org > > Subject: Re: Lots of prepends - AS20912 case > > > > On Fri, 20 Feb 2009, Dorn Hetzel wrote: > > > > > Replacing what is conventially thought to be a string with > > an integer > > > multiplier seems a massive violation of the principle of > > least astonishment. > > > > On a Cisco running 12.0S: > > > > route-map test1 > > set as-path prepend last-as ? > > <1-10> number of last-AS prepends > > > > Cisco seems to be doing more sensible limits, but I do agree > > that the feature makes sense. > > > > There are two ways of handling when someone puts in a very > > high number to number of prepends: > > > > 1. Say "out of limit" and disallow it in the config checker. > > 2. Actually prepend the number of times specified. > > > > The option done here: > > > > 3. Prepend number of times entered modulo 256, is just broken. > > > > -- > > Mikael Abrahamsson email: swm...@swm.pp.se > > >
