Probably isn't a good reason, but some providers configure their filters
this way. You may want to change your route-map to prepend once, instead of
twice.
-Steve
At 12:42 PM 10/19/99 -0400, Vijay Gill wrote:
>On Tue, 19 Oct 1999, Steve Austin wrote:
>
>> Most likely UUnet is filtering out the prepended as-path. You may want to
>> contact them and check to see if they are allowing you to do this.
>
>
>Could you explain the reasoning as to _why_ anyone would filter out a
>prepended as-path?
>
>
>As for the original poster, how do you know your routes disappear? Are you
>using some sort of looking glass? What may be happening is that if you
>prepend enough times to UUNET, the path becomes unattractive, even
>internally, and all traffic starts to go over sprint. Since the UUNET
>path is no longer the best path for almost any router, and only the best
>path is propagated further, it may lead to a disappearance of the uunet
>path from looking glasses.
>
>/vijay
>
>
>> -Steve
>>
>> At 11:03 AM 10/19/99 -0400, Eric J Merkel wrote:
>> >
>> >We currently have 3 upstream T1's. 1 with UUNET and 2 with Sprint.
Right now
>> >our UUNET T1(incoming traffic) is maxing out at 97% at night while our
>> >Sprint T1's are at about 40% (incoming traffic).
>> >
>> >I was trying to prepend our AS path to our announcements goint to UUNet to
>> >hopefully even things out but for some reason when doing this, all of our
>> >routes thru UUNET disappeared most likely to a misconfiguration on my part
>> >(I am a BGP newbie). I have since taken our the route-map statement and
>> >routes thru UUNET are visible again thru the DIGEX looking glass.
>> >
>> >Here are my UUnet neighbor statements:
>> >neighbor 137.39.2.108 remote-as 701
>> >neighbor 137.39.2.108 ebgp-multihop 2
>> >neighbor 137.39.2.108 update-source FastEthernet0/0
>> >neighbor 137.39.2.108 next-hop-self
>> >neighbor 137.39.2.108 route-map SETPATH out
>> >neighbor 137.39.2.108 filter-list 10 out
>> >
>> >ip as-path access-list 10 permit ^$
>> >
>> >access-list 1 permit 0.0.0.0
>> >
>> >route-map SETPATH permit 10
>> > match ip address 1
>> > set as-path prepend 13638 13638
>> >
>> >I have also tried it as such:
>> >route-map SETPATH permit 10
>> > match as-path 10
>> > set as-path prepend 13638 13638
>> >
>> >
>> >Anyone got any ideas? BTW I am doing a clear ip bgp 137.39.2.108 after the
>> >changes are complete. :)
>> >
>> >
>> >Eric Merkel / MetaLink Technologies, Inc
>> >~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*
>> >Email: merkel@metalink.net
>> >Phone: 419-782-3472 X304
>> >~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*
>> >
>> >
>>
>>
>
>Vijay Gill |The (paying) customer is always right.
>wrath@cs.umbc.edu, vijay@umbc.edu | - Piercarlo Grandi
>http://www.gl.umbc.edu/~vijay | Eagles may soar, but weasels don't get
>These are my opinions only. | sucked into jet engines.
>
>
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