Ada beberapa istilah dan teknologi baru di dunia Service Provider, yaitu:
1. Segment Routing MPLS (SR MPLS)
2. Segment Routing over IPv6 (SRv6)
3. PCE (Path Computation Element)
4. dst.
Apa istilah-istilah di atas, bisa di baca-baca di website [1]. Untuk introduction to Segment Routing, bisa dibaca-baca di link [2].
[1] http://segment-routing.net
[2] https://community.cisco.com/t5/service-providers-documents/asr9000-xr-introduction-to-segment-routing/ta-p/3166037
Saya coba ngelab menggunakan XRv, ngelabnya yang sederhana saja. Sebenernya mau test L3VPN tsb apakah akan jalan atau tidak jika protokol untuk distribusi label itu tidak menggunakan LDP. Eh ternyata benar, bisa juga :-D

Di R1 , R2, R3 running SR MPLS, dan running MP-BGP antara R1 dan R3. CE-01 punya loopback 100.100.100.100/32 dan CE-02 punya Lo0 100.100.100.101/32.
RP/0/0/CPU0:R1#show mpls ldp nei
Sat Jan 9 13:46:50.792 UTC
RP/0/0/CPU0:R1#show mpls interface
Sat Jan 9 13:46:53.382 UTC
Interface LDP Tunnel Static Enabled
————————– ——– ——– ——– ——–
GigabitEthernet0/0/0/0 No No No Yes
GigabitEthernet0/0/0/1 No No No Yes
RP/0/0/CPU0:R1#show mpls forward
Sat Jan 9 13:46:56.342 UTC
Local Outgoing Prefix Outgoing Next Hop Bytes
Label Label or ID Interface Switched
—— ———– —————— ———— ————— ————
17002 Pop SR Pfx (idx 1002) Gi0/0/0/0 10.1.2.2 0
17003 17003 SR Pfx (idx 1003) Gi0/0/0/0 10.1.2.2 120838
24001 Pop SR Adj (idx 1) Gi0/0/0/0 10.1.2.2 0
24002 Pop SR Adj (idx 3) Gi0/0/0/0 10.1.2.2 0
24005 Aggregate BLUE: Per-VRF Aggr[V] \
BLUE 0
24006 Unlabelled 100.100.100.100/32[V] \
Gi0/0/0/2 192.168.100.2 102340
RP/0/0/CPU0:R1#
LDP neighborship tidak terbentuk, artinya di router ini belum/tidak running LDP. Namun, forwardingnya sudah ada dan terlihat berbeda ‘labelisasi’ nya dari LDP.
RP/0/0/CPU0:R1#show bgp vpnv4 unicas summ | b Neig
Sat Jan 9 13:51:57.031 UTC
Neighbor Spk AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down St/PfxRcd
3.3.3.3 0 65000 205 202 26 0 0 02:47:51 2
RP/0/0/CPU0:R1#
Terlihat prefix yang diterima di R1 under vrf BLUE.
RP/0/0/CPU0:R1#show bgp vpnv4 unicas | b Status
Sat Jan 9 13:52:17.030 UTC
Status codes: s suppressed, d damped, h history, * valid, > best
i – internal, r RIB-failure, S stale, N Nexthop-discard
Origin codes: i – IGP, e – EGP, ? – incomplete
Network Next Hop Metric LocPrf Weight Path
Route Distinguisher: 65000:100 (default for vrf BLUE)
*> 100.100.100.100/32 192.168.100.2 0 32768 ?
*>i100.100.100.101/32 3.3.3.3 0 100 0 ?
*> 192.168.100.0/30 0.0.0.0 0 32768 ?
*>i192.168.101.0/30 3.3.3.3 0 100 0 ?
Processed 4 prefixes, 4 paths
RP/0/0/CPU0:R1#
Bagaimana jika kita test ping dari CE ke CE.
CE-01#ping 100.100.100.101 source lo0
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 100.100.100.101, timeout is 2 seconds:
Packet sent with a source address of 100.100.100.100
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 11/13/17 ms
CE-01#