BGP fail-over

Discussion in 'Cisco' started by yellow, Sep 8, 2006.

  1. yellow

    yellow Guest

    Hi,

    My site is running multi-home bgp, with two different provider. Both
    line are ethernet connection to my two edge routers. As ethernet is a
    kind of 'always on' connection. if any problem with any ISP, such as
    the gateway down, the isp interface status is still up up in my edge
    router. How does bgp track the problem and failover to second isp
    automatically, any parameter ?
     
    yellow, Sep 8, 2006
    #1
    1. Advertising

  2. yellow

    chris Guest

    "yellow" <> wrote in message
    news:...
    > Hi,
    >
    > My site is running multi-home bgp, with two different provider. Both
    > line are ethernet connection to my two edge routers. As ethernet is a
    > kind of 'always on' connection. if any problem with any ISP, such as
    > the gateway down, the isp interface status is still up up in my edge
    > router. How does bgp track the problem and failover to second isp
    > automatically, any parameter ?
    >


    If the ISP is down then your BGP session will also drop out and so those
    routes will become invalid.

    Chris.
     
    chris, Sep 8, 2006
    #2
    1. Advertising

  3. yellow

    chris Guest

    "yellow" <> wrote in message
    news:...
    > Hi,
    >
    > My site is running multi-home bgp, with two different provider. Both
    > line are ethernet connection to my two edge routers. As ethernet is a
    > kind of 'always on' connection. if any problem with any ISP, such as
    > the gateway down, the isp interface status is still up up in my edge
    > router. How does bgp track the problem and failover to second isp
    > automatically, any parameter ?
    >


    If the ISP is down then your BGP session will also drop out and so those
    routes will become invalid.

    Chris.
     
    chris, Sep 8, 2006
    #3
  4. yellow

    chris Guest

    "chris" <> wrote in message
    news:...
    >
    > "yellow" <> wrote in message
    > news:...
    >> Hi,
    >>
    >> My site is running multi-home bgp, with two different provider. Both
    >> line are ethernet connection to my two edge routers. As ethernet is a
    >> kind of 'always on' connection. if any problem with any ISP, such as
    >> the gateway down, the isp interface status is still up up in my edge
    >> router. How does bgp track the problem and failover to second isp
    >> automatically, any parameter ?
    >>

    >
    > If the ISP is down then your BGP session will also drop out and so those
    > routes will become invalid.
    >
    > Chris.
    >


    Sorry for the double post. It was stuck in the outbox :-(
     
    chris, Sep 8, 2006
    #4
  5. yellow

    Merv Guest

    BGP uses TCP as a transport so eventually the BGP session will timeout
    and the routes learned via that session will be yanked.


    The keepalive and holdtime can be specified for each BGP neighbour:

    neighbor [ip-address | peer-group-name] timers keepalive holdtime

    Sets the keepalive and hold-time timers (in seconds) for the specified
    peer or peer group.
     
    Merv, Sep 8, 2006
    #5
  6. In article <>,
    "Merv" <> wrote:

    > BGP uses TCP as a transport so eventually the BGP session will timeout
    > and the routes learned via that session will be yanked.


    Actually, it doesn't depend on TCP killing the session. It also sends
    its own periodic KEEPALIVE messages; if it doesn't see these messages
    from the peer, it kills the session itself.

    --
    Barry Margolin,
    Arlington, MA
    *** PLEASE post questions in newsgroups, not directly to me ***
    *** PLEASE don't copy me on replies, I'll read them in the group ***
     
    Barry Margolin, Sep 9, 2006
    #6
  7. yellow

    Merv Guest

    There is also the BGP external fast failover feature that can be enabled
     
    Merv, Sep 9, 2006
    #7
  8. In article <>,
    yellow <> wrote:
    >Hi,
    >
    >My site is running multi-home bgp, with two different provider. Both
    >line are ethernet connection to my two edge routers. As ethernet is a
    >kind of 'always on' connection. if any problem with any ISP, such as
    >the gateway down, the isp interface status is still up up in my edge
    >router. How does bgp track the problem and failover to second isp
    >automatically, any parameter ?


    Receive a default-route from each ISP and re-distribute.
    Then your clients will always have a valid route out.
    In my case I cross-connect the two edge routers with iBGP
    also to load-share the two connections.

    alan
     
    Alan Strassberg, Sep 17, 2006
    #8
  9. yellow

    theapplebee

    Joined:
    Jun 19, 2009
    Messages:
    67
    Location:
    USA
    For the fast convergence, make sure lower BGP hold time set.
    However, you don't want to set the number lower than 5~6 sec.
     
    theapplebee, Sep 8, 2009
    #9
    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. Guest

    PIX 515e Fail-over

    Guest, Apr 5, 2004, in forum: Cisco
    Replies:
    2
    Views:
    800
    Guest
    Apr 14, 2004
  2. harald rüger
    Replies:
    0
    Views:
    540
    harald rüger
    Oct 25, 2004
  3. papi
    Replies:
    4
    Views:
    2,220
    theapplebee
    Sep 8, 2009
  4. Theo Markettos

    VOIP over VPN over TCP over WAP over 3G

    Theo Markettos, Feb 3, 2008, in forum: UK VOIP
    Replies:
    2
    Views:
    920
    Theo Markettos
    Feb 14, 2008
  5. prk016

    BGP Fail Over Monitoring

    prk016, Aug 23, 2012, in forum: Cisco
    Replies:
    0
    Views:
    635
    prk016
    Aug 23, 2012
Loading...

Share This Page