Re: Load balancing 2 ISP's & BGP?

Discussion in 'Cisco' started by Rob, Jul 24, 2003.

  1. Rob

    Rob Guest

    I don't believe I can do that. I don't control it.



    On Wed, 23 Jul 2003 13:47:37 GMT, Barry Margolin
    <> wrote:

    >In article <>,
    >Rob <> wrote:
    >>Since SBC is not a tier 1, very little traffic is coming across this
    >>new T1. In order to "even out" the providers, I have prepended our
    >>ASN twice onto UUNet so that SBC/Sprint would be a little more
    >>preferred. This has done a decent job on inbound traffic. However,
    >>we still have hardly any outbound utilization on the SBC T1.
    >>Sometimes it is zero.
    >>
    >>Any recommendations to force, via BGP, some of the outbound traffic to
    >>use SBC and not all MCI?

    >
    >Prepend your ASN to the incoming routes as well.
     
    Rob, Jul 24, 2003
    #1
    1. Advertising

  2. Rob

    Rob Guest

    Um... I don't think that would do anything beneficial. Might even
    stop everything flowing altogether.



    On Thu, 24 Jul 2003 14:05:16 GMT, Barry Margolin
    <> wrote:

    >In article <>,
    >Rob <> wrote:
    >>I don't believe I can do that. I don't control it.

    >
    >What don't you control? If you could prepend when advertising, why can't
    >you prepend when receiving:
    >
    >router bgp #####
    > neighbor x.x.x.x route-map prepend out
    > neighbor x.x.x.x route-map prepend in
    >
    >>
    >>On Wed, 23 Jul 2003 13:47:37 GMT, Barry Margolin
    >><> wrote:
    >>
    >>>In article <>,
    >>>Rob <> wrote:
    >>>>Since SBC is not a tier 1, very little traffic is coming across this
    >>>>new T1. In order to "even out" the providers, I have prepended our
    >>>>ASN twice onto UUNet so that SBC/Sprint would be a little more
    >>>>preferred. This has done a decent job on inbound traffic. However,
    >>>>we still have hardly any outbound utilization on the SBC T1.
    >>>>Sometimes it is zero.
    >>>>
    >>>>Any recommendations to force, via BGP, some of the outbound traffic to
    >>>>use SBC and not all MCI?
    >>>
    >>>Prepend your ASN to the incoming routes as well.

    >>
     
    Rob, Jul 25, 2003
    #2
    1. Advertising

  3. In article <>,
    Rob <> wrote:
    >Um... I don't think that would do anything beneficial. Might even
    >stop everything flowing altogether.


    I don't see why. It will just increase the length of the AS paths of the
    routes that you receive from the Tier 2 ISP. It won't have any effect on
    the routes you receive from the Tier 1 ISP.

    >On Thu, 24 Jul 2003 14:05:16 GMT, Barry Margolin
    ><> wrote:
    >
    >>In article <>,
    >>Rob <> wrote:
    >>>I don't believe I can do that. I don't control it.

    >>
    >>What don't you control? If you could prepend when advertising, why can't
    >>you prepend when receiving:
    >>
    >>router bgp #####
    >> neighbor x.x.x.x route-map prepend out
    >> neighbor x.x.x.x route-map prepend in
    >>
    >>>
    >>>On Wed, 23 Jul 2003 13:47:37 GMT, Barry Margolin
    >>><> wrote:
    >>>
    >>>>In article <>,
    >>>>Rob <> wrote:
    >>>>>Since SBC is not a tier 1, very little traffic is coming across this
    >>>>>new T1. In order to "even out" the providers, I have prepended our
    >>>>>ASN twice onto UUNet so that SBC/Sprint would be a little more
    >>>>>preferred. This has done a decent job on inbound traffic. However,
    >>>>>we still have hardly any outbound utilization on the SBC T1.
    >>>>>Sometimes it is zero.
    >>>>>
    >>>>>Any recommendations to force, via BGP, some of the outbound traffic to
    >>>>>use SBC and not all MCI?
    >>>>
    >>>>Prepend your ASN to the incoming routes as well.
    >>>

    >



    --
    Barry Margolin,
    Level(3), Woburn, MA
    *** DON'T SEND TECHNICAL QUESTIONS DIRECTLY TO ME, post them to newsgroups.
    Please DON'T copy followups to me -- I'll assume it wasn't posted to the group.
     
    Barry Margolin, Jul 25, 2003
    #3
  4. Rob

    Rob Guest

    So do I prepend the AS both in and out on the tier 1 provider?
    Or do I prepend out on tier 1 and use prepend in on the tier 2?

    -Rob


    On Thu, 24 Jul 2003 23:35:46 GMT, Barry Margolin
    <> wrote:

    >In article <>,
    >Rob <> wrote:
    >>Um... I don't think that would do anything beneficial. Might even
    >>stop everything flowing altogether.

    >
    >I don't see why. It will just increase the length of the AS paths of the
    >routes that you receive from the Tier 2 ISP. It won't have any effect on
    >the routes you receive from the Tier 1 ISP.
    >
    >>On Thu, 24 Jul 2003 14:05:16 GMT, Barry Margolin
    >><> wrote:
    >>
    >>>In article <>,
    >>>Rob <> wrote:
    >>>>I don't believe I can do that. I don't control it.
    >>>
    >>>What don't you control? If you could prepend when advertising, why can't
    >>>you prepend when receiving:
    >>>
    >>>router bgp #####
    >>> neighbor x.x.x.x route-map prepend out
    >>> neighbor x.x.x.x route-map prepend in
    >>>
    >>>>
    >>>>On Wed, 23 Jul 2003 13:47:37 GMT, Barry Margolin
    >>>><> wrote:
    >>>>
    >>>>>In article <>,
    >>>>>Rob <> wrote:
    >>>>>>Since SBC is not a tier 1, very little traffic is coming across this
    >>>>>>new T1. In order to "even out" the providers, I have prepended our
    >>>>>>ASN twice onto UUNet so that SBC/Sprint would be a little more
    >>>>>>preferred. This has done a decent job on inbound traffic. However,
    >>>>>>we still have hardly any outbound utilization on the SBC T1.
    >>>>>>Sometimes it is zero.
    >>>>>>
    >>>>>>Any recommendations to force, via BGP, some of the outbound traffic to
    >>>>>>use SBC and not all MCI?
    >>>>>
    >>>>>Prepend your ASN to the incoming routes as well.
    >>>>

    >>
     
    Rob, Jul 25, 2003
    #4
  5. In article <>,
    Rob <> wrote:
    >So do I prepend the AS both in and out on the tier 1 provider?
    >Or do I prepend out on tier 1 and use prepend in on the tier 2?


    You should prepend both on the tier 1 (I just noticed that I got that
    backward in my previous response). You want to even out the AS path
    lengths in both directions.

    --
    Barry Margolin,
    Level(3), Woburn, MA
    *** DON'T SEND TECHNICAL QUESTIONS DIRECTLY TO ME, post them to newsgroups.
    Please DON'T copy followups to me -- I'll assume it wasn't posted to the group.
     
    Barry Margolin, Jul 25, 2003
    #5
  6. Rob

    Rob Guest

    Gotta say Barry, it sounds real easy, but I've never seen this example
    given on any Cisco docs. Have you tried it successfully?



    On Fri, 25 Jul 2003 14:00:34 GMT, Barry Margolin
    <> wrote:

    >In article <>,
    >Rob <> wrote:
    >>So do I prepend the AS both in and out on the tier 1 provider?
    >>Or do I prepend out on tier 1 and use prepend in on the tier 2?

    >
    >You should prepend both on the tier 1 (I just noticed that I got that
    >backward in my previous response). You want to even out the AS path
    >lengths in both directions.
     
    Rob, Jul 25, 2003
    #6
  7. In article <>,
    Rob <> wrote:
    >Gotta say Barry, it sounds real easy, but I've never seen this example
    >given on any Cisco docs. Have you tried it successfully?


    I think I've advised some of our customers to do it, and can't recall
    anyone ever saying it didn't work. It seems intuitively obvious to me that
    it should work as expected.

    --
    Barry Margolin,
    Level(3), Woburn, MA
    *** DON'T SEND TECHNICAL QUESTIONS DIRECTLY TO ME, post them to newsgroups.
    Please DON'T copy followups to me -- I'll assume it wasn't posted to the group.
     
    Barry Margolin, Jul 25, 2003
    #7
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. Terry Baranski

    Re: Load balancing 2 ISP's & BGP?

    Terry Baranski, Jul 24, 2003, in forum: Cisco
    Replies:
    2
    Views:
    1,298
    Barry Margolin
    Jul 24, 2003
  2. Matt
    Replies:
    1
    Views:
    688
    Vincent C Jones
    Oct 17, 2005
  3. Matt
    Replies:
    1
    Views:
    4,098
  4. Yoann Roman

    Cisco for load balancing w/o BGP

    Yoann Roman, Oct 11, 2006, in forum: Cisco
    Replies:
    6
    Views:
    1,054
    Yoann Roman
    Nov 1, 2006
  5. pshemko
    Replies:
    1
    Views:
    572
Loading...

Share This Page