Recently the company that i work(changed job again ) for has roll out segment routing. This is still limited to 7 countries.
Next step for us is to look into PCEP-SR/BGP-LU/and SR-TE ( this post ). We don't have loots of rsvp-te tunnels, ~90 or so, 70% used for igp-shortcuts uneaqul load balancing and rest for services ( some customers want to go via a specific subsea cable , for some reason :) ).
We don't have a controller , and probably never will... and it's going to be a while while the segment features are present in all 3 vendors( that we use).
Anywho this is about SR-TE ... what it supposed to do and current implementation on JNP.
SR-TE is defined in:
https://tools.ietf.org/html/draft-ietf-idr-segment-routing-te-policy-00 ;
Mapping traffic over this is defined :
https://tools.ietf.org/html/draft-filsfils-spring-segment-routing-policy-01;
JNP implementation of SR-TE is not there , so end of blogpost.... What they do have at this stage , is a static SR feature.
This means instead of learning the SR policy via BGP ( and help me crete a proper post ) the current implementation is static for now...
In terms of mapping traffic onto the SR ( draft-filsfils-spring-segment-routing-policy-01) this is fine , at least the use case below.
Topology
vmx8->10.11.11.11/32 follows the spf ; xrv2->xrv1
Label traffic is SR-based ; top-most label 800001
root@vmx8> show route 10.11.11.11
inet.0: 22 destinations, 23 routes (22 active, 0 holddown, 0 hidden)
@ = Routing Use Only, # = Forwarding Use Only
+ = Active Route, - = Last Active, * = Both
10.11.11.11/32 *[BGP/170] 00:00:00, MED 0, localpref 100, from
10.1.1.1
AS path: I, validation-state: unverified
> to 10.2.8.2 via ge-0/0/0.0, Push 800001
inet.3: 5 destinations, 5 routes (5 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
10.1.1.1/32 *[L-ISIS/14] 00:03:29, metric 20
> to 10.2.8.2 via ge-0/0/0.0, Push
800001
root@vmx8> traceroute 10.11.11.11
traceroute to 10.11.11.11 (10.11.11.11), 30 hops max, 52 byte packets
1 10.2.8.2 (10.2.8.2) 116.892 ms 2.880 ms 2.667 ms
MPLS Label=800001 CoS=0 TTL=1 S=1
2 10.1.2.1 (10.1.2.1) 4.990 ms * 4.668 ms
The goal is to create an SR-TE policy so that traffic flows vmx8->xrv2-xrv5>xrv3->xrv1. Ideally this would have been created by BGP SR-TE,
but that is not working in the current code ... so let's do it static.
set protocols source-packet-routing segment-list sr-te_to_xrv1 xrv5 label 800005
set protocols source-packet-routing segment-list sr-te_to_xrv1 xrv3 label 800003
set protocols source-packet-routing segment-list sr-te_to_xrv1 xrv1 label 800001
set protocols source-packet-routing source-routing-path to_xrv1 to 10.1.1.1
set protocols source-packet-routing source-routing-path to_xrv1 color 0
set protocols source-packet-routing source-routing-path to_xrv1 primary sr-te_to_xrv1
What this does is , create the SR-TE with a label stack of 3, the next hop label is not needed.
root@vmx8> show spring-traffic-engineering lsp
To State LSPname
10.1.1.1-0<c> Up to_xrv1
the -0<c> is really important. This is the color of the tunnel... this as this as SLA agreement. In fact let create another one with different color. The 10.1.1.1 is the end-point , matching the next-hop of the ipv4 unicast route.
This time is xrv2-xrv5-xrv2-xrv1
set protocols source-packet-routing segment-list sr-te_to_xrv1#2 xrv5 label 800005
set protocols source-packet-routing segment-list sr-te_to_xrv1#2 xrv2 label 800002
set protocols source-packet-routing segment-list sr-te_to_xrv1#2 xrv1 label 800001
set protocols source-packet-routing source-routing-path to_xrv1#2 to 10.1.1.1
set protocols source-packet-routing source-routing-path to_xrv1#2 color 10
set protocols source-packet-routing source-routing-path to_xrv1#2 primary sr-te_to_xrv1#2
As expected :
root@vmx8> show spring-traffic-engineering lsp
To State LSPname
10.1.1.1-0<c> Up to_xrv1
10.1.1.1-10<c> Up to_xrv1#2
root@vmx8> show route table inetcolor.0
inetcolor.0: 2 destinations, 2 routes (2 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
10.1.1.1-0<c>/64
*[SPRING-TE/8] 00:08:58, metric 1, metric2 20
> to 10.2.8.2 via ge-0/0/0.0, Push 800001, Push 800003, Push 800005(top)
10.1.1.1-10<c>/64
*[SPRING-TE/8] 00:08:58, metric 1, metric2 20
> to 10.2.8.2 via ge-0/0/0.0, Push 800001, Push 800002, Push 800005(top)
Now , one of the method to inject traffic into the SR-TE is to color a destination prefix. So let's do just that. I'm using yabgp to insert
the bgp route.
the json it's below:
{
"attr": {
"1": 0,
"2": [[2, []]],
"3": "10.1.1.1",
"5": 200,
"8": ["NO_ADVERTISE"],
"16": [[779, 0]]
},
"nlri":["10.11.11.11/32"]
}
Test 1:
Advertise 10.11.11.11/32 with next-hop 10.1.1.1 and with extended community 779 (BGP_EXT_COM_COLOR = 0x030b) with value 0.
root@vmx8> show route 10.11.11.11
inet.0: 22 destinations, 24 routes (22 active, 0 holddown, 0 hidden)
@ = Routing Use Only, # = Forwarding Use Only
+ = Active Route, - = Last Active, * = Both
10.11.11.11/32 *[BGP/15] 00:00:06, localpref 200, from 10.97.97.2
AS path: I, validation-state: unverified
> to 10.2.8.2 via ge-0/0/0.0, Push 800005
[BGP/170] 00:01:56, MED 0, localpref 100, from 10.1.1.1
AS path: I, validation-state: unverified
> to 10.2.8.2 via ge-0/0/0.0, Push 800001
root@vmx8> ...32 extensive | match "color|Protocol next hop"
Protocol next hop: 10.1.1.1-0<c>
Communities: no-advertise color:0:0
As expected route is received with corect color , and the next hop is the SR-TE policy.
Traceroute :
root@vmx8> traceroute 10.11.11.11
traceroute to 10.11.11.11 (10.11.11.11), 30 hops max, 52 byte packets
1 10.2.8.2 (10.2.8.2) 99.071 ms 215.040 ms 6.419 ms
MPLS Label=800005 CoS=0 TTL=1 S=0
MPLS Label=800003 CoS=0 TTL=1 S=0
MPLS Label=800001 CoS=0 TTL=1 S=1
2 10.2.5.5 (10.2.5.5) 5.144 ms 4.763 ms 4.597 ms
MPLS Label=800003 CoS=0 TTL=1 S=0
MPLS Label=800001 CoS=0 TTL=2 S=1
3 10.3.5.3 (10.3.5.3) 4.751 ms 4.642 ms 4.752 ms
MPLS Label=800001 CoS=0 TTL=1 S=1
4 10.1.3.1 (10.1.3.1) 4.762 ms * 44.309 ms
Test 2:
Advertise 10.11.11.11/32 with next-hop 10.1.1.1 and with extended community 779 (BGP_EXT_COM_COLOR = 0x030b) with value 10.
{
"attr": {
"1": 0,
"2": [[2, []]],
"3": "10.1.1.1",
"5": 200,
"8": ["NO_ADVERTISE"],
"16": [[779, 10]]
},
"nlri":["10.11.11.11/32"]
}
root@vmx8> ...extensive | match "Communities|Protocol next hop"
Protocol next hop: 10.1.1.1-10<c>
Communities: no-advertise color:0:10
root@vmx8> traceroute 10.11.11.11
traceroute to 10.11.11.11 (10.11.11.11), 30 hops max, 52 byte packets
1 10.2.8.2 (10.2.8.2) 6.217 ms 5.156 ms 4.686 ms
MPLS Label=800005 CoS=0 TTL=1 S=0
MPLS Label=800002 CoS=0 TTL=1 S=0
MPLS Label=800001 CoS=0 TTL=1 S=1
2 10.2.5.5 (10.2.5.5) 4.722 ms 4.470 ms 4.569 ms
MPLS Label=800002 CoS=0 TTL=1 S=0
MPLS Label=800001 CoS=0 TTL=2 S=1
3 10.2.5.2 (10.2.5.2) 4.681 ms 4.500 ms 4.715 ms
MPLS Label=800001 CoS=0 TTL=1 S=1
4 10.1.2.1 (10.1.2.1) 4.806 ms * 9.379 ms
