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BGP in JunOS - Help! Route advertisements, Prefix lists, policy statement, filter!!??

  • 1.  BGP in JunOS - Help! Route advertisements, Prefix lists, policy statement, filter!!??

    Posted 10-04-2017 12:33

    Hi, really struggling to work out these terms and how they build a way for advertising a prefix out using Juniper devices

     

    Cisco appears to be straighforward, use the 'network command' - there doesnt appear to be the equivalent in Juniper? Is that correct?

     

    So how does Juniper advertise prefixes?  Network prefixes, static route, routes from other protocols (redistributed routes)

     

    Does anyone have any simple breakdown of how and syntax with an explanation of waht/how the terms prefix lists, policy statements, filters interact and build these advertisements? I'm going around in circles and I know there is a simple explanation somewhere?

     

    Any help really appreciated - 

     

    Thanks

     

     

     

     


    #BGPADVERTISEMENTROUTE


  • 2.  RE: BGP in JunOS - Help! Route advertisements, Prefix lists, policy statement, filter!!??

    Posted 10-04-2017 13:01

    have a look at

    https://www.juniper.net/us/en/training/jnbooks/day-one/fundamentals-series/routing-internet-protocol/

     

    a very good day one book also about BGP

    Routing the Internet Protocol Juniper Day One Book

     

     

     

     

     

     

     

     

     

     

     

     

     

    regards

     

    alexander



  • 3.  RE: BGP in JunOS - Help! Route advertisements, Prefix lists, policy statement, filter!!??

    Posted 10-08-2017 23:19

    Great, thanks appreciate it



  • 4.  RE: BGP in JunOS - Help! Route advertisements, Prefix lists, policy statement, filter!!??

    Posted 10-08-2017 06:40

    You need to set routing options for aggregating your subnet, set router-id, the create the export filter, then export the filter to peer.

     

    set routing-options aggregate route 1.2.3.0/24

    set routing-options router-id 1.2.3.4

    set policy-options policy-statement to-peer term export_prefix from protocol aggregate

    set policy-options policy-statement to-peer term export_prefix from route-filter 1.2.3.0/24 exact

    set policy-options policy-statement to-peer term export_prefix then accept

    set policy-options policy-statement to-peer then reject

    set protocols bgp group peer

    set protocols bgp group peer type external

    set protocols bgp group peer peer-as 1234
    set protocols bgp group peer local-as 1234

    set protocols bgp group peer neighbor 1.2.3.4 export to-peer

     

    This will get you started.

    You might need to set hold-time, import rules etc.



  • 5.  RE: BGP in JunOS - Help! Route advertisements, Prefix lists, policy statement, filter!!??

    Posted 10-08-2017 23:19

    Hi, thanks, so all of this syntax is needed compared to Cisco:

     

    R1#conf t

    R1(config)# router bgp 500

    R1(config-router)# network 2.2.2.2 255.255.255.255   (< --- advertising my loopback into BGP)

     

    Is that right? Juniper will need  about 10 lines to do the same thing?



  • 6.  RE: BGP in JunOS - Help! Route advertisements, Prefix lists, policy statement, filter!!??

    Posted 10-09-2017 13:30

    Network statements with Cisco redistributes specific routes into BGP. To do the same thing with Junos, you need to create a policy that you can use to redistribute specific routes into BGP. Here's a Junos equivalent to the Cisco config you posted:

     

     

    set policy-options policy-statement EXPORT-BGP term LOOPBACK from route-filter 2.2.2.2/32 exact
    set policy-options policy-statement EXPORT-BGP term LOOPBACK then accept
    set protocols bgp group eBGP export EXPORT-BGP