[j-nsp] BGP multipath trouble.

[Vladimir S. Blazhkun]

This is unavailable option in 6.4 :( And it's undesirable for me to
enable it on router, where load-balancing is required only for 2 peers
(with more than 200 existing), because it can cause consistent
unnecessary best path transitions.

> Try configuring external-router-id:
>
> http://www.juniper.net/techpubs/software/junos/junos76/swconfig76-routin
> g/html/bgp-summary42.html
>
> HTHs
>
>
>
>> -----Original Message-----
>> From: juniper-nsp-bounces at puck.nether.net
>> [mailto:juniper-nsp-bounces at puck.nether.net] On Behalf Of
>> Vladimir S. Blazhkun
>> Sent: Tuesday, August 15, 2006 12:18 PM
>> To: juniper-nsp at puck.nether.net
>> Subject: [j-nsp] BGP multipath trouble.
>>
>>
>> Hello, i have a trouble with load-balancing traffic to the
>> same prefix, with the same AS_PATH, and other metrics. I have
>> 2 upstream connections to different ASes, see all required
>> outputs below. Both next-hops are not installed for
>> forwarding traffic (seems first one is preferred due
>> implementation of draft-ietf-idr-avoid-transition). Are there
>> any workarounds for this in JUNOS 6.4?
>>
>> # show protocols bgp group UPstream-peers
>>
>> type external;
>> graceful-restart {
>>      disable;
>> }
>> multipath;
>> neighbor XXX.XXX.0.125 {
>>      passive;
>>      import [ remove-private-as remove-bogus-nets
>> long-prefixes flap-damping UPstream-XXXXX-Import ];
>>      export UPstream-XXXXX-Announce;
>>      peer-as XX16;
>> }
>> neighbor XXX.XXX.99.45 {
>>      passive;
>>      import [ remove-private-as remove-bogus-nets
>> long-prefixes flap-damping UPstream-XXXXXXXXXXX-Import ];
>>      export UPstream-XXXXXXXXXXX-Announce;
>>      peer-as XX99;
>> }
>>
>> # run show route forwarding-table destination 4/8
>>
>> Routing table: inet
>> Internet:
>> Destination        Type RtRef Next hop           Type Index
>> NhRef Netif
>> 4.0.0.0/8          user     0                    indr   603 13757
>>                                XXX.XXX.0.125      ucst   589
>>    3 fe-0/3/1.104
>>
>> # run show route 4/8 exact detail
>>
>> 4.0.0.0/8 (2 entries, 1 announced)
>>          *BGP    Preference: 170/-101
>>                  Next-hop reference count: 219519
>>                  Source: XXX.XXX.0.125
>>                  Next hop: XXX.XXX.0.125 via fe-0/3/1.104, selected
>>                  Protocol next hop: XXX.XXX.0.125 Indirect
>> next hop: 863a700 603
>>                  State: <Active Ext>
>>                  Local AS: XXXXX Peer AS:  XX16
>>                  Age: 2:48:29    Metric: 200     Metric2: 0
>>                  Task: BGP_XX16.XXX.XXX.0.125+26165
>>                  Announcement bits (3): 0-KRT
>> 4-BGP.0.0.0.0+179 5-Resolve inet.0
>>                  AS path: XX16 3356 I (Atomic) Aggregator:
>> 3356 4.69.130.2
>>                  Communities: 3356:0 3356:3 3356:100 3356:123
>> 3356:575 3356:2011
>>                  Localpref: 100
>>                  Router ID: XXX.XX.0.216
>>           BGP    Preference: 170/-101
>>                  Next-hop reference count: 542310
>>                  Source: XXX.XXX.99.45
>>                  Next hop: XXX.XXX.99.45 via fe-0/3/1.105, selected
>>                  Protocol next hop: XXX.XXX.99.45 Indirect
>> next hop: 863a400 587
>>                  State: <Ext>
>>               !! ->> Inactive reason: Active preferred
>>                  Local AS: XXXXX Peer AS:  XX99
>>                  Age: 2:47:18    Metric: 200     Metric2: 0
>>                  Task: BGP_XX99.XXX.XXX.99.45+17205
>>                  AS path: XX99 3356 I (Atomic) Aggregator:
>> 3356 4.69.130.10
>>                  Communities:
>>                  Localpref: 100
>>                  Router ID: XX.XXX.146.98

--
Vladimir S. Blazhkun,
JNSS-M JNCIA-M #773 JNCIS-M #1100 JNCIP-M #289 JNCI-M
JNCIA-J JNCI-J