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Re: Add communities on direct routes in Juniper


From: "Jason R. Rokeach via NANOG" <nanog () nanog org>
Date: Sun, 15 Oct 2023 12:50:24 +0000

Hi Stanislav,
I believe this is what you are looking for:

[edit]
jcluser@Lothlorien-MX1# show | compare 
[edit interfaces lo0 unit 0 family inet]
        address 10.0.0.0/32 { ... }
+       address 5.5.5.5/32;
[edit protocols bgp]
-   export IPV4-STATIC;
+   export [ IPV4-STATIC TAG-DIRECT ];
[edit policy-options]
+   policy-statement TAG-DIRECT {
+       from {
+           protocol direct;
+           route-filter 5.5.5.5/32 exact;
+       }
+       then {
+           community set MYCOMMUNITY;
+           accept;
+       }
+   }
[edit policy-options]
+   community MYCOMMUNITY members 5:5;

[edit]
jcluser@Lothlorien-MX1# commit 
commit complete

[edit]
jcluser@Lothlorien-MX1# run show route advertising-protocol bgp 172.19.0.2 detail | find 5.5.5.5 
* 5.5.5.5/32 (1 entry, 1 announced)
 BGP group RR-LOADBALANCER type External
     Nexthop: Self
     AS path: [65000] I 
     Communities: 5:5

Regards,
Jason R. Rokeach


------- Original Message -------
On Sunday, October 15th, 2023 at 8:29 AM, Saku Ytti - saku at ytti.fi <saku_at_ytti_fi_wamwii () simplelogin co> wrote:


Unfortunately not yet, as far as I know. Long time ago I gave this to
my account team

Title: Direct routes must support tag and or community
Platform: Trio, priority MX80, MPC2
JunOS: 12.4Rx
Command: 'set interfaxe ge-4/2.0 family inet address 10.42.42.1/24
tag|community X'
JTAC: n/a
ER:
- Router must be able to add tags communities to direct routes directly, like
it does for static routes

Usage Case:
Trivial way to signal route information to BGP. Often tag/community is used
by service providers to singal 'this is PI/PA prefix, leak it to internet' or
'this is backup route, reduce its MED'. However for some reason it is only
supported for static routes, while usage scenario and benefits are exactly the
same for direct routes.

On Sun, 15 Oct 2023 at 15:27, Stanislav Datskevych via NANOG
nanog () nanog org wrote:

Dear all,

Is there a way to add BGP communities on direct (interface) routes in Junipers? The task looks to be simple but the 
solution eludes me.
In Cisco/Arista, for example, I could use "network 192.0.2.0/24 route-map <SOME_MAP_THAT_ADDS_COMMUNITIES>".

In Juniper it seems to be impossible. I even tried putting interface-routes into rib-group with an import policy.
But it seems the import policy only works on importing routes into Secondary routing tables (e.g. inet.50), and not 
into the Primary one (inet.0).

I know it's possible to add communities on later stage while announcing networks to peers, in [protocols bgp group 
<name> export]. But I'd better slap the community on the routes right when they're imported into RIB, not when they 
announced to peers.

Thanks in advance.



--
++ytti


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