Routing

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  • 1.  BGP Import Filtering...

    Posted 11-09-2008 11:19

    Hello,

     

    I am trying to filter BGP announces I am receiving. While the filter seems to be working, system still stores all the received routes in memory.

     

    > show bgp summary
    Groups: 1 Peers: 1 Down peers: 0
    Table          Tot Paths  Act Paths Suppressed    History Damp State    Pending
    inet.0            272954          0          0          0          0          0
    Peer                     AS      InPkt     OutPkt    OutQ   Flaps Last Up/Dwn State|#Active/Received/Accepted/Damped...
    XX.XX.153.57          XX21      54435         43       0       0       17:25 0/272954/0/0         0/0/0/0
     

    I can see alll these 200k routes when I look for hidden routes using 'show route hidden' command. 

     

    This is causing 'rpd' process to use 100mb of memory instead of 10mb which it originally uses when it starts.

     

    When I do a similar configuration in Cisco routers, the incoming route advertisements get discarded altogether. Is this normal for a Juniper router? is there a way to discard all incoming route advertisements? 

     

    Thanks,

    Evren

     



  • 2.  RE: BGP Import Filtering...

    Posted 11-09-2008 23:12

    Hi Evren,

     

    One Simple solution is to ask your ISP to advertise only default route or limited no. of routes(ISP Customer routes),  if you are not interested in receiving the full internet table or your router is not capable of supporting it(don't have enough memory).

     

     



  • 3.  RE: BGP Import Filtering...

    Posted 11-09-2008 23:27

    Hi,

     

    juniper routers only discard incoming BGP routes if are causing sanity check fail means AS loop etc otherwise all incoming routes are stored in RIB-IN table and after import policy is imposed routes are placed in RIB-local (used for forwarding). The advantage is that we dont have to clear bgp neighbourship after imposing import policy, enforcing neighbour to redisvertisement bgp routes, so that routes are passed through import policy.

     

    Thanks



  • 4.  RE: BGP Import Filtering...

    Posted 11-10-2008 07:54
    Thanks for the replies. I could ask from my upstream provider to advertise a minimal set of routes however I think I just wont bother. I dont really have memory problems so...  But this was working wonderfully in the cisco router which will be replaced with a juniper j-series router. I guess I just have to live with this...


  • 5.  RE: BGP Import Filtering...
    Best Answer

    Posted 11-21-2008 13:52

    You can acheive this by configuring the bgp neighbor with "keep none".  With this config, routes rejected by policy will no longer be stored in memory.  But, then you loose the immediate routing-table update, due to inbound policy changes.  All of those routes would have to be re-learned.

     

    http://www.juniper.net/techpubs/software/junos/junos93/swconfig-routing/keep.html#id-13337068

     

    Regards,

    Ben


    #memory
    #BGP
    #tips


  • 6.  RE: BGP Import Filtering...

    Posted 11-21-2008 14:12
    Ben, you are a genious 🙂 The memory usage of 'rpd' fell from 100MB to 15MB, this is exactly what I needed...


  • 7.  RE: BGP Import Filtering...

    Posted 03-02-2009 13:24

    Hi

    Where or how can I see how many memory the table is taking?

     

    best regards

    Iglu



  • 8.  RE: BGP Import Filtering...

    Posted 03-02-2009 22:20
    If I remember correctly, I used the 'top' command from shell for that purpose.


  • 9.  RE: BGP Import Filtering...

    Posted 03-03-2009 06:48
    'Show task memory', and  'show tasks memory detail' provide you with the memory usage of rpd (Routing Process).

    @Iglu wrote:

    Hi

    Where or how can I see how many memory the table is taking?

     

    best regards

    Iglu