#CiscoLive
SRv6 Fundamentals
Jakub Horn
Principal Technical Marketing Engineer
BRKMPL-2203
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3
Agenda
•
Introduction
•
SRv6 Dataplane
•
SRv6 Control Plane
•
Addressing for SRv6
•
SRv6 Migration
•
Conclusion
BRKMPL-2203
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4
Understanding Today’s Service Creation
Limited Cross-domain Automation, Cumbersome Service Assurance
Legacy Central Office
Complex E2E Quality of Service (QoS)
Metro Network Domain
Core Network Domain
L2VPN
L3VPN
Data Center Domain
VXLAN
VNF VNF
Aggregation
Ethernet
MPLS
IP
Access
Centralized Services Delivery
Hardware
Appliances
End-to-end service provisioning is lengthy and complex
• Multiple network domains under different management teams
• Manual operations
• Heterogeneous underlay and overlay networks
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5
SR-MPLS: SDN ready
“Network as a Fabric” for Service Creation
Homogenous Cross-domain Automation & Assurance
Cloud Scale Networking
Central Office
Access
SDN
Control
SDN
Metro Network Domain
SDN
Core Network Domain
SDN
Data Center Domain
VPN L2/L3
Aggregation
VNF
Segment Routing
VNF
Compute
VNF VNF
Leaf
Centralized Services Delivery
Spine
End-to-end service provisioning is simple
• Multiple network domains under same management teams
• Automated operations
• Homogenous underlay and overlay networks
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6
SRv6: SDN, NfV, 5G ready
“Network as an API” for Service Creation
Homogenous Cross-domain Automation & Assurance
Cloud Scale Networking
Central Office
Access
SDN
Control
SDN
Metro Network Domain
SDN
Core Network Domain
SDN
Data Center Domain
Segment Routing v6 (transport, services and programmability)
Aggregation
VNF
VNF
Compute
VNF VNF
Leaf
Centralized Services Delivery
Spine
End-to-end service provisioning is integrated with NfV, SDN
• Multiple network domains under same management teams
• Automated operations
• Integrated underlay and overlay networks (NfV)
• Network as API (NfV)
• Hyper Scale (5G)
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7
SRv6
IPv6 Segment Routing Header
(SRH)
tc
flow label
payload length
next header
hop limit
IPv6 Header
SRv6
ver
source address
• IPv6 Header
destination address
• Destination IP address
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10
tc
flow label
6
next header
payload length
hop limit
IPv6 Header
SRv6
ver
source address
• IPv6 Header
destination address
• Destination IP address
source port
• Next header field:
destination port
• TCP, UDP, ICMP....
TCP Header
sequence number
acknowledgment number
hlen
reserved
code bits
checksum
window
urgent
options
TCP data
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11
tc
flow label
4
next header
payload length
hop limit
IPv6 Header
SRv6
ver
source address
• IPv6 Header
• Next header field:
• TCP, UDP, ICMP....
ver
tos
hl
id
ttl
length
flags
protocol
• IPv4, IPv6
fragment offset
header checksum
source IP address
destination IP address
IP Packet
• Destination IP address
destination address
IP data
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12
tc
flow label
next143
header
payload length
hop limit
IPv6 Header
SRv6
ver
source address
• IPv6 Header
destination address
• Destination IP address
• Next header field:
destination MAC
destination MAC
• TCP, UDP, ICMP....
source MAC
source MAC
• IPv4, IPv6, L2
L2 Frame
ether type
L2 Payload
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13
flow label
next 51
header
payload length
hop limit
source address
• IPv6 Header
• Next header field:
next header
6
payload len
reserved
security parameters index
• TCP, UDP, ICMP....
AH
• Destination IP address
destination address
IPv6 Header
tc
sequence number
• IPv4, IPv6, L2
authentication data
• Hop by Hop, Dest. Options,
Fragmentation, Authentication
Header …
source port
destination port
sequence number
acknowledgment number
hlen
reserved
code bits
checksum
window
urgent
options
#CiscoLive
TCP data
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TCP Header
SRv6
ver
tc
flow label
next 43
header
payload length
hop limit
IPv6 Header
SRv6
ver
source address
• IPv6 Header
• Destination IP address
• Next header field:
destination address
next header
hdr ext len
routing type
segments left
• TCP, UDP, ICMP....
Routing Header
• IPv4, IPv6, L2
• Hop by Hop, Dest. Options,
Fragmentation, Authentication
Header …
•
Routing Header
0 Source Route (deprecated)
1 Nimrod (deprecated)
2 Type 2 (RFC 6275)
3 RPL (RFC 6554)
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• Next header field:
IPv6 Header
destination address
next header
hdr ext len
first segment
flags
routing
4 type
segments left
tag
SID[0]
• IPv4, IPv6, L2
SID[1]
RFC 8754
Routing Header
hop limit
source address
• TCP, UDP, ICMP....
•
next 43
header
payload length
• Destination IP address
• Hop by Hop, Dest. Options,
Fragmentation, Authentication
Header …
flow label
0 Source Route (deprecated)
SRH
• IPv6 Header
tc
RFC 2460
SRv6
ver
SID[n-1]
1 Nimrod (deprecated)
2 Type 2 (RFC 6275)
Optional TLVs
3 RPL (RFC 6554)
4 SRH (RFC 8754)
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16
tc
flow label
next 43
header
payload length
hop limit
IPv6 Header
SRH
ver
source address
• Segment Routing Header
• Pointer to very first SID
next header
hdr ext len
first segment
flags
routing
4 type
segments left
tag
SID[0]
SID[1]
SRH
• First Segment
destination address
SID[n-1]
Optional TLVs
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17
SRH
tc
flow label
next 43
header
payload length
hop limit
IPv6 Header
ver
source address
• Segment Routing Header
ACTIVEaddress
SID
destination
• Segments left
• Pointer to Active SID
next header
hdr ext len
first segment
flags
copy
• Pointer to very first SID
routing
4 type
segments left
tag
SID[0]
• Active SID always in destination addr
SID[1]
SRH
• First Segment
ACTIVE SID
SID[n-1]
Optional TLVs
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18
SID Structure -Locator
128 Bits Like IPv6 address but different semantics
1111:2222:3333:4444:5555:6666:7777:8888
Locator
Function
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19
SRv6 Full SID
S
R
R1
R2
R3
R4
BGP:2001:db8:0:4:eeee::
SA:2001::1
DA:2001:db8:0:1:1::
NH:RH
Type:4(SRH)
NH:IPv4|SL:3
Segment List:
[0]:2001:db8:0:4:eeee::
[1]:2001:db8:0:3:48::
[2]:2001:db8:0:2:1::
[3]:2001:db8:0:1:1::
SA:2001::1
DA:2001:db8:0:2:1::
NH:RH
SA:2001::1
DA:2001:db8:0:3:48::
NH:RH
Type:4(SRH)
NH:IPv4|SL:2
Segment List:
[0]:2001:db8:0:4:eeee::
[1]:2001:db8:0:3:48::
[2]:2001:db8:0:2:1::
[3]:2001:db8:0:1:1::
Type:4(SRH)
NH:IPv4|SL:1
Segment List:
[0]:2001:db8:0:4:eeee::
[1]:2001:db8:0:3:48::
[2]:2001:db8:0:2:1::
[3]:2001:db8:0:1:1::
#CiscoLive
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SA:2001::1
DA:2001:db8:0:4:eeee::
NH:IPv4
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20
SID Structure
128 Bits Like IPv6 address but different semantics
1111:2222:3333:4444:5555:6666:7777:8888
Locator
Block
Node
ID
Function
Padding
Function
Argument
#CiscoLive
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Padding
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21
SRv6 uSID
SRv6 uSID format
SRV6 Encapsulation
SA:2001::1
DA:2001:db8:0:4:1:0:0:0
NH:RH
: 0100 : =SRV6 uSID
Type:4(SRH)
NH:IPv4|SL:1
Segment List:
[0]: 2001:db8:0:5:45:0:0:0
[1]: 2001:db8:0:4:1:0:0:0
[2]: 2001:db8:0:3:48:0:0:0
[3]: 2001:db8:0:2:1:0:0:0
[4]: 2001:db8:0:1:42:0:0:0
16 bits here, but can be anything
SA:7.5.4.3
DA:11.6.19.71
Port:UDP
SRV6 uSID Container
UDP Header/Data
2001 :0db8 : 0100 : 0200 : 0300 : 0400 : 0500 : 0000
SRv6 uSID uSID uSID uSID uSID uSID EoC
Block
1
2
3
4
5
6
32 bits here,
but can be anything
SRV6 uSID Encapsulation
SA:2001::1
DA:2001:db8:100:200:300:400:500::
NH:IPv4
SA:7.5.4.3
DA:11.6.19.71
Port:UDP
UDP Header/Data
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23
SRv6 uSID F3216
S
R
R1
R2
R3
R4
BGP:2001:db8:4:eeee::
SA:2001::1
DA:2001:db8:1:2:3:e000:4:eeee
NH:IPV4
SA:2001::1
DA:2001:db8:2:3:e000:4:eeee::
NH:IPV4
SA:2001::1
DA:2001:db8:3:e000:4:eeee::
NH:IPV4
#CiscoLive
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SA:2001::1
DA:2001:db8:4:eeee::
NH:IPV4
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24
SRv6 uSID More Than 6 SIDs?
1
2
100->200->300->400->500->600->700->800->900->a00->b00
Carrier 1
2001 : 0db8 : 0100 : 0200 : 0300 : 0400 : 0500 : 0600
Carrier 2
2001 : 0db8 : 0700 : 0800 : 0900 : 0a00 : 0b00 : 0000
3
4
5
SA:2001::1
DA:2001:db8:b00::
DA:2001:db8:a00:b00::
DA:2001:db8:900:a00:b00::
DA:2001:db8:800:900:a00:b00::
DA:2001:db8:700:800:900:a00:b00::
DA:2001:db8:600:0::
DA:2001:db8:500:600:0::
DA:2001:db8:400:500:600:0::
DA:2001:db8:300:400:500:600:0::
DA:2001:db8:200:300:400:500:600:0
DA:2001:db8:100:200:300:400:500:600
RH
NH:IPv4
6
Shift & Forward
END of Carrier
-> is there SRH?
Decrement SL
Copy New SID (Carrier)
PSP
Type:4(SRH)
NH:IPv4|SL:1
SL:0
Segment List:
[0]: 2001:db8:700:800:900:a00:b00::
SA:7.5.4.3
DA:11.6.19.71
Port:UDP
7
8
9
a
b
UDP Header/Data
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25
Sets, Global ID Block (GIB), Local ID Block (LIB)
• Within a Block, SIDs are allocated: FCBB:BB00:SSII::/48
0x0000
• SID can be:
• Global: shortest path to a node – globally unique
• Local: a local function – not globally unique
GIB
• 256 Sets in a Block, identified by “SS“
• Global Sets (GIB): first “S“ values 0 to D
• 224 global Sets → 224 * 256 = 56k global IDs
0xdfff
0xe000
• Local Sets (LIB): first “S“ values E to F
• 32 local Sets → 32 * 256 = 8k local IDs
LIB
0xffff
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26
SRv6 uSID Configuration
Name to reference
segment-routing
uSID
srv6
locators
locator MAIN
micro-segment behavior unode psp-usd
prefix fcbb:bb00:1::/48
Locator Prefix
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27
SRv6
Network Programming
END– Default endpoint (Node SID)
• Decrement SL
• Copy Active SID
• Forward
• Different Flavors:
•
End
•
End with PSP
•
End with USP
•
End with PSP & USP
•
End with USD
•
End with PSP & USD
•
End with USP & USD
•
End with PSP, USP & USD
SA:2001::1
DA:2001:db8:0:2:1::
NH:RH
SA:2001::1
DA:2001:db8:0:1:1::
NH:RH
R1
Type:4(SRH)
NH:IPv4|SL:3
Segment List:
[0]:2001:db8:0:4:eeee::
[1]:2001:db8:0:3:e000::
[2]:2001:db8:0:2:1::
[3]:2001:db8:0:1:1::
Type:4(SRH)
NH:IPv4|SL:2
Segment List:
[0]:2001:db8:0:4:eeee::
[1]:2001:db8:0:3:e000::
[2]:2001:db8:0:2:1::
[3]:2001:db8:0:1:1::
•
End with NEXT-ONLY-CSID
•
End with NEXT-CSID
•
End with NEXT-CSID & PSP
•
End with NEXT-CSID & USP
•
End with NEXT-CSID, PSP & USP
•
End with NEXT-CSID & USD
•
End with NEXT-CSID, PSP & USD
•
End with NEXT-CSID, USP & USD
•
End with NEXT-CSID, PSP, USP & USD
#CiscoLive
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R2
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29
uN=END with Next – Default endpoint (Node SID)
• Decrement SL
• Copy Active SID
• Forward
SA:2001::1
DA:2001:db8:2::
NH:RH
SA:2001::1
DA:2001:db8:0:1::
NH:RH
Type:4(SRH)
NH:IPv4|SL:3
Segment List:
[0]:2001:db8:4:eeee::
[1]:2001:db8:3:e000::
[2]:2001:db8:2::
[3]:2001:db8:1::
R1
Type:4(SRH)
NH:IPv4|SL:2
Segment List:
[0]:2001:db8:4:eeee::
[1]:2001:db8:3:e000::
[2]:2001:db8:2::
[3]:2001:db8:1::
R2
R1
SA:2001::1
DA:2001:db8:2:3:e000:4:eeee
NH:IPV4
R2
Better way:
• Shift & Forward
SA:2001::1
DA:2001:db8:1:2:3:e000:4:eeee
NH:IPV4
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30
uA=END.X with Next – (Adjacency SID)
SA:2001::1
DA:2001:db8:4:eeee::
NH:IPV4
SA:2001::1
DA:2001:db8:3:e000:4:eeee::
NH:IPV4
R
R3
R4
• Shift & Forward to SPECIFIC INTERFACE
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31
uDT4=END.DT4, uDT6=END.DT6
Endpoint with Decapsulation and Table Lookup
• Decapsulate and Table Lookup (VRF)
• Same as Per VRF Label Allocation (aggregate label)
• Must be last function in SID list
SA:2001::1
DA:2001:db8:4:eeee::
NH:IPV4
IPv4 Packet
R4
#CiscoLive
IPv4 Packet
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32
SRv6 functions: Steering and Services
Codename
Behavior
End
uN
Endpoint
[Node SID]
End.X
uA
Endpoint with Layer-3 cross-connect
[Adj SID]
Endpoint bound to an SRv6 policy
[BSID]
Endpoint bound to an SRv6 encapsulation policy
[BSID]
End.B6.Insert
uB6.Insert
End.B6.Encap
uB6.Encaps
End.DX6
uDX6
Endpoint with decapsulation and IPv6 cross-connect
[L3VPN Per-CE]
End.DX4
uDX4
Endpoint with decapsulation and IPv4 cross-connect
[L3VPN Per-CE]
End.DT6
uDT6
Endpoint with decapsulation and specific IPv6 table lookup
[L3VPN Per-VRF]
End.DT4
uDT4
Endpoint with decapsulation and specific IPv4 table lookup
[L3VPN Per-VRF]
End.DX2
uDX2
Endpoint with decapsulation and L2 cross-connect
[E-LINE]
Endpoint with decapsulation and L2 unicast lookup / flooding
[E-LAN]
Endpoint with decapsulation and MPLS table lookup
[Interworking]
Headend with Insertion / Encapsulation of / into an SRv6 policy
[TiLFA]
H. Encaps.L2
H.Encaps Applied to Received L2 Frames
[L2 Port Mode]
H.Encaps.M
H.Encaps Applied to MPLS Label Stack
[Interworking]
End.DT2U/M
uDT2U/M
End.DTM
uDTM
H.Insert / H.Encaps
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33
ISIS Extensions
Functions might be signaled differently
Signalling
IGP
BGP-LS
BGPIP/VPN
Signalling
IGP
BGPLS
End, uN
Yes
Yes
T.insert
Yes
End.X, uA
Yes
Yes
T.Encap
Yes
End.T
Yes
Yes
End.DX4,uDX4
Yes
Yes
Yes
Yes
End.DX2,uDX2
Yes
Yes
END.DT4,uDT4
Yes
Yes
Yes
Yes
End.DX6,uDX6
End.DT6,uDT6
End.B
Yes
Yes
BGPIP/VPN
Locator – routing table
Yes
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35
ISIS for SRv6
LSP (Link State Packet):
TLVs:
Hostname:
Interfaces:
Lo0
fcbb:0:2::1/128
r2
Hu0/0/0/0
uA:fcbb:0:2:e001::
Structure: BL=32;NL=16;FL=16;AL=0
Hu0/0/0/1
uA:fcbb:0:2:e002::
Structure: BL=32;NL=16;FL=16;AL=0
Neighbors:
IP addresses:
Locator:
Capabilities:
Lo0
r1
r3
fcbb:0:2::1/128
2001:12::2/64
fcbb:0:2::/48
uN:fcbb:0:2::
Locator:
Hu0/0/0/1
fcbb:0:2::/48 r2 uA:fcbb:0:2:e002::
uN:fcbb:0:2::
r3
Structure: BL=32;NL=16;FL=16;AL=0
Structure: BL=32;NL=16;FL=0,AL=80
uA:fcbb:0:2:e001::
Structure: BL=32;NL=16;FL=16;AL=0
:
Structure: BL=32;NL=16;FL=0,AL=80
Algorithms ……
SIDs can insert
SIDs can decap
……….
#CiscoLive
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2001:12::2/64
Hu0/0/0/0
r1
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36
SRv6 ISIS Configuration
router isis 1
address-family ipv6 unicast
segment-routing srv6
locator MAIN
Name of the Locator
This will result in:
• Locator is advertised
• uN function is advertised
• uA for each ISIS interface is allocated and advertised
#CiscoLive
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37
BGP for Overlay
BGP
VPNv4 :10.10.22.0/24
NH:2001::3
RD-1:1
RT -1:1
uDT4– fcbb:bb00:3:e002::
• No Changes Required!
iBGP
IPv4 :10.10.22.0/24
NH:10.1.21.1
#CiscoLive
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3
10.3.22.22
Locator – fcbb:bb00:3::/48
10.3.22.3
IPv6
uDT4 – fcbb:bb00:3:e002::
1
eBGP
2001::3
2001::1
10.1.21.1
CE
10.1.21.21
eBGP
IPv4 :10.10.22.0/24
NH:10.3.22.22
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CE
39
L3 VPN Dataplane
SA:2001::1
DA:fcbb:bb00:3:e002::
NH:IPv4
SA:10.10.21.10
DA:10.10.22.10
NH:UDP
2001::1
2001::3
UDP Header/Data
SA:10.10.21.10
DA:10.10.22.10
NH:UDP
#CiscoLive
BRKMPL-2203
10.3.22.22
3
IPv6
10.3.22.3
1
uDT 4– fcbb:bb00:3:e002::
UDP Header/Data
10.1.21.1
CE
10.1.21.21
UDP Header/Data
SA:10.10.21.10
DA:10.10.22.10
NH:UDP
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CE
40
SRv6 L3 VPN Configuration
router bgp 1
address-family vpnv4 unicast
vrf BestEffort
rd 1:1
address-family ipv4 unicast
segment-routing srv6
locator MAIN
alloc mode per-vrf
Name of the Locator
Single DT function is allocated
per VRF and AF
This will result in:
• uDT4 function is allocated
• All prefixes are advertised with uDT4 function
#CiscoLive
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41
SRv6
Addressing
Separation between SIDs and addresses
• Infrastructure addressing and SRv6 SID allocation belong to two different
planes and are different
• Infrastructure IP addresses (e.g., link interfaces, loopbacks) are allocated on the
management plane
• SRv6 SIDs are allocated on the service plane
• SRv6 SIDs are assigned to a node independently from the IP addressing of
that node
• Even if they are both represented as IPv6 addresses, infrastructure
addresses and SIDs cannot be merged and should be allocated off
different blocks.
An existing IPv6 address plan is not a constraint
for a future SRv6 SID allocation plan.
#CiscoLive
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43
Terminology – uSID F3216
• uSID F3216: uSID format with
• uSID Block size: 32 bits
• ID size: 16 bits
• uSID F3216 structure:
Block
ID
SID Space (/24)
Set
ID
Node
ID
PPPP:PPBB:SSII
Block (/32)
16-bit
ID
#CiscoLive
BRKMPL-2203
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44
SRv6 Space allocation recommendation
• Private range allocation
• Recommended allocation
✓
• Use /24 sub-range from ULA FC00::/8 space
• FCBB:BB00::/24, with B indicating a nibble value picked by operator
• Public range allocation
• Supported, not advised
⚠️
• From allocated public GUA range
#CiscoLive
BRKMPL-2203
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45
uSID Block per slice (Flex Algo) if possible
• 256 Blocks are available in the SRv6 Space:
FCBB:BBTT::/32,
with TT = slice ID
• Multiple Blocks can be concurrently used on a node
• 63 Blocks available on DNX1 platforms (TT = 00 to 3E)
• We assume 2 slices (Blocks), e.g.:
• FCBB:BB00::/32
Low-cost slice (algo 0)
• FCBB:BB01::/32
Low-delay slice (algo 128)
#CiscoLive
BRKMPL-2203
 focus, other Blocks are similar
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46
Set Allocation Example
Block: FCBB:BB00::/32
Region 1
Core Region
Region 2
600 nodes

3 Sets
200 nodes

1 Set
400 nodes

2 Sets
FCBB:BB00:0200::/40
FCBB:BB00:0300::/40
FCBB:BB00:0400::/40
FCBB:BB00:0100::/40
FCBB:BB00:0500::/40
FCBB:BB00:0600::/40
• If a region outgrows its allocated Sets, then allocate more Sets to this region
#CiscoLive
BRKMPL-2203
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47
uSID Allocation Example
Block: FCBB:BB00::/32
Region 1
Core Region
Region 2
600 nodes
3 Sets (02, 03, 04)
200 nodes
1 Set (01)
400 nodes
2 Sets (05, 06)
7
FCBB:BB00:0207::/48
256
FCBB:BB00:0301::/48
518
FCBB:BB00:0406::/48
7
FCBB:BB00:0107::/48
7
FCBB:BB00:0507::/48
256
FCBB:BB00:0601::/48
• Remaining unallocated uSIDs in Sets are for future growth
#CiscoLive
BRKMPL-2203
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48
Summarization
Block: FCBB:BB00::/32
Region 1
Core Region
Region 2
600 nodes
3 Sets (02, 03,
04)
200 nodes
1 Set (01)
400 nodes
2 Sets (05,
06)
summarize
summarize
FCBB:BB00:0200::/40
FCBB:BB00:0300::/40
FCBB:BB00:0400::/40
FCBB:BB00:0500::/40
FCBB:BB00:0600::/40
#CiscoLive
BRKMPL-2203
Summarization gain:
× 256
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49
SRv6 Migration
Dual Connected PE
BGPv4
Loopback addr
ISISv4
Lo:1.1.1.1
VPN prefix +lbl
Loopback label
LDPv4
PE
SRv6 PE
DUAL Connected PE
MPLS PE
BGPv4
BGPv6
LDPv4
ISISv4
Lo:1.1.1.1
VPN prefix +SID
Locators
ISISv6
PE
Lo0: A::2
ISISv6
PE
Lo0: A::2
VRF
VRF
1.
1.
VRF
BGPv6
1.
10.10.1.0/24
10.10.1.0/24
10.10.1.0/24
#CiscoLive
BRKMPL-2203
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51
Lo0:3.3.3.3
MPLS Network –Day 0
PE3VRF 10.10.3.0/24
1.
ISISv4 LDPv4
BGPv4
Lo:1.1.1.1
PE1
10.10.1.0/24 VRF
1.
Lo:2.2.2.2
ISISv4 LDPv4
P
BGPv4
ISISv4 LDPv4
PE2VRF 10.10.2.0/24
1.
ISISv4 LDPv4
BGPv4
RR
v4
Lo:4.4.4.4
#CiscoLive
BRKMPL-2203
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52
Lo0: A::3
Lo0:3.3.3.3
Enabling IPv6 Routing- Day
1
PE3
VRF
1.
10.10.3.0/24
ISISv6 ISISv4
LDPv4
BGPvpnv4
Lo0: A::1
Lo:1.1.1.1
PE1
10.10.1.0/24 VRF
1.
ISISv4 LDPv4
ISISv6
ISISv4 LDPv4
P
Lo0: A::2
Lo:2.2.2.2
PE2VRF 10.10.2.0/24
1.
ISISv6
ISISv6
ISISv4
BGPvpnv4
RR
v6
BGPvpnv4
RR
v4
Lo0: A::4
Lo:4.4.4.4
#CiscoLive
BRKMPL-2203
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53
Lo0: A::3
Lo0:3.3.3.3
Enabling SRv6 –PE1&PE2 PE3
VRF
1.
PE1
10.10.3.0/24
ISISv4
LDPv4
Locator: B1::/48
Lo0: A::1
Lo:1.1.1.1
10.10.1.0/24 VRF
1.
ISISv4 LDPv4
ISISv6
P
BGPvpnv4 Locator: B2::/48
Lo0: A::2
Lo:2.2.2.2
ISISv4 LDPv4
PE2VRF 10.10.2.0/24
1.
ISISv6
ISISv6
ISISv4
BGPvpnv4
BGPvpnv4 BGPvpnv4
RR
v6
BGPvpnv4
RR
v4
Lo0: A::4
Lo:4.4.4.4
#CiscoLive
BRKMPL-2203
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54
Lo0: A::3 Locator: fcbb:0:3::/48
Lo0:3.3.3.3
Enabling SRv6 –Last PE PE3
10.10.3.0/24
VRF
Locator: fcbb:0:1::/48
Lo0: A::1
Lo:1.1.1.1
PE1
10.10.1.0/24 VRF
1.
ISISv6 ISISv4
LDPv4
BGPvpnv4
ISISv4 LDPv4
ISISv6
1.
P
BGPvpnv4 Locator: fcbb:0:2::/48
Lo0: A::2
Lo:2.2.2.2
ISISv4 LDPv4
PE2VRF 10.10.2.0/24
1.
ISISv6
ISISv6
ISISv4
BGPvpnv4
BGPvpnv4 BGPvpnv4
RR
v6
BGPvpnv4
RR
v4
Lo0: A::4
Lo:4.4.4.4
#CiscoLive
BRKMPL-2203
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55
Lo0: A::3 Locator: fcbb:0:3::/48
Removing V4
Locator: fcbb:0:1::/48
Lo0: A::1
PE1
10.10.1.0/24 VRF
1.
PE3VRF 10.10.3.0/24
1.
BGPvpnv4
ISISv6
ISISv6
Locator: fcbb:0:2::/48
Lo0: A::2
P
PE2VRF 10.10.2.0/24
1.
ISISv6
ISISv6
BGPvpnv4
BGPvpnv4
RR
v6
Lo0: A::4
#CiscoLive
BRKMPL-2203
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56
SRv6 Dual PE Configuration
router bgp 1
neighbor A::4
address-family vpnv4 unicast
encapsulation-type srv6
route-policy RRv6 out
neighbor 4.4.4.4
address-family vpnv4 unicast
route-policy RRv4 out
vrf 1
address-family ipv4 unicast
mpls alloc enable
segment-routing srv6
locator MAIN
alloc mode per-vrf
Via RPL we set specific BGP
attributes to to prefixes
ie Local Preference
towards RRv6 and RRv4
Policy towards v6 RR
Policy towards v4 RR
Allocates Labels for all prefixes in VRF
Allocates SIDs for all prefixes in VRF
from Locator MAIN
#CiscoLive
BRKMPL-2203
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57
SRv6 uSID
Conclusion
Simplicity Always Prevails
LDP
RSVP-TE
BGP 3108
MPLS
UDP/VxLAN
NSH
Furthermore, with more
scale
#CiscoLive
and functionality
BRKMPL-2203
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62
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