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set routing options static route doesn't appear in routing table nor forwarding table

  • 1.  set routing options static route doesn't appear in routing table nor forwarding table

    Posted 08-10-2023 11:02

    Interesting problem.

    Model: srx300
    Junos: 23.1R1.8
    Im sure its something to do with IRB interface but please help me out.

    SRX has 3 ports in use.

    1. Ethernet 0/0 with pppoe as default route - OK
    2. ethernet 0/1 with 2nd ISP where I route particular subnets - OK 
    3. LAN interface is an irb.0 interface which is a logical interface for remaining ge0/0/x  ports e.g  irb.0                   up    up   inet     10.101.50.1/24

    There is a switch connected to it , I have my PC connected to the switch and all working fine.

    Now, I added 2nd Router to the switch. Its IP 10.101.50.41

    I want SRX to route BACK to 10.101.50.41 to find 10.101.51.0/24 

    However, when I set the route using set route options command, the configuration is taken but nothing appears in the forwarding table:

     show | match route
                    source-route-option;
                        router {
            route 0.0.0.0/0 next-hop pp0.0;
            route 10.101.51.0/24 next-hop 10.101.50.41;

    show rotuing terse:

    @SRX-A> show route terse
     
    inet.0: 32 destinations, 33 routes (32 active, 0 holddown, 0 hidden)
    + = Active Route, - = Last Active, * = Both
     
    A V Destination        P Prf   Metric 1   Metric 2  Next hop        AS path
    * ? 0.0.0.0/0          S   5                       >pp0.0
    * ? 10.101.50.0/24     D   0                       >lo0.0
      ?                    D   0                       >irb.0
    * ? 10.101.50.1/32     L   0                        Local
    * ? 10.101.50.10/32    A  12                       >10.101.50.1
    * ? 10.101.50.11/32    A  12                       >10.101.50.1
    * ? 10.101.50.12/32    A  12                       >10.101.50.1
    * ? 10.101.50.13/32    A  12                       >10.101.50.1
    * ? 10.101.50.14/32    A  12                       >10.101.50.1
    * ? 10.101.50.15/32    A  12                       >10.101.50.1
    * ? 10.101.50.16/32    A  12                       >10.101.50.1
    * ? 10.101.50.17/32    A  12                       >10.101.50.1
    * ? 10.101.50.39/32    A  12                       >10.101.50.1
    * ? 10.101.50.199/32   L   0                        Local
    I can ping 10.101.50.41 only if I specify source , otherwise it won't ping.
    I have a feeling its got something to do with this:
    @SRX-A> show interfaces detail irb.0
      Logical interface irb.0 (Index 71) (SNMP ifIndex 508) (Generation 136)
        Flags: Up SNMP-Traps 0x0 Encapsulation: ENET2
        Bandwidth: 1Gbps
        Routing Instance: default-switch Bridging Domain: vlan-trust
    but Im not sure.

    Any thoughts? 


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    MARIUSZ PIANKA
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  • 2.  RE: set routing options static route doesn't appear in routing table nor forwarding table

    Posted 08-13-2023 06:37

    Since the SRX has an interface in the subnet this will be the local broadcast domain for that subnet.

    irb.0                   up    up   inet     10.101.50.1/24

    You would only be able to create more specific route subnets not the entire 24 as an overriding route.

    When you use ping on the SRX there is a default mechanism to choose which ip address to use for the request.  This can mean that certain external device ping requests have to use the specify address source when the path from the default address is not valid for either sending out or return of the ping request on the outside device.



    ------------------------------
    Steve Puluka BSEET - Juniper Ambassador
    IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP - Retired)
    http://puluka.com/home
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