SRTE ODN not working. What is the problem ?

samarjit dutta · ‎11-19-2019

Topology Brief

Three isolated IGP domains AGG-A, AGG-B, CORE running ISIS level 2 only
Segment routing is enabled on all IGP domains
CORE10 (SRPCE) running BGP-LS all border routers to learn topology from all three domains
For reachability between PE/PCC to SRPCE/CORE10 ibgp IPv4 is used. IPv4 bgp is running on PEs, Border routers and SRPCE. Border routers are reflecting route and updating next-hop
SRPCE/CORE10 propagating only its loopback 11.0.0.1/32 and suppressing all other IPv4 routes
PEs are maintaining VPNv4 neighborship with CORE11. CORE11 reflecting VPNV4 routes without changing the next-hop
PE routes are configured as PCC and maintaining peering with SRPCE CORE10

Objective:

Creating ODN tunnel from CORE7 to CORE10 for a prefix (20.200.0.1/32) attached with CORE10 (in vrf A)

Problem: BGP path is pointing towards the Attribute-set but then communication between PCC and PCE seems to be not triggering. Path showing down

Current status:

RP/0/0/CPU0:CORE-7#show bgp vpnv4 unicast vrf A 20.200.0.1

Mon Nov 18 22:37:44.249 UTC

BGP routing table entry for 20.200.0.1/32, Route Distinguisher: 100:1

Versions:

Process bRIB/RIB SendTblVer

Speaker 28 28

Last Modified: Nov 18 22:06:02.837 for 00:31:41

Paths: (1 available, no best path)

Not advertised to any peer

Path #1: Received by speaker 0

Not advertised to any peer

Local

10.0.0.1 T:DEFAULT (inaccessible) from 11.0.0.1 (10.0.0.1)

Received Label 24005

Origin incomplete, metric 2, localpref 100, valid, internal, import-candidate, not-in-vrf

Received Path ID 0, Local Path ID 0, version 0

Extended community: OSPF route-type:0:1:0x0 OSPF router-id:20.13.10.1 RT:100:1

Originator: 10.0.0.1, Cluster list: 11.0.0.1

TE tunnel attribute-set DEFAULT, down, registered, bsid none, if-handle 0x00000000

!

RP/0/0/CPU0:CORE-7#show mpls traffic-eng tunnels brief

Mon Nov 18 22:46:43.822 UTC

!

Config

!

router bgp 100

neighbor 11.0.0.1

remote-as 100

update-source Loopback0

address-family vpnv4 unicast

route-policy TEST in

!

route-policy TEST

if destination in (20.200.0.0/24 le 32) then

set mpls traffic-eng attributeset DEFAULT

endif

end-policy

!

mpls traffic-eng

attribute-set p2p-te DEFAULT

pce

!

logging events all

path-selection

metric igp

!

PCC to PCE peering

!

RP/0/0/CPU0:CORE-7#show mpls traffic-eng pce peer ipv4 11.0.0.1

Mon Nov 18 22:48:12.286 UTC

PCE Address 11.0.0.1

State Up

PCEP has been up for: 02:11:32

Precedence 255

Learned through:

Static Config

Sending KA every 30 s

Time out peer if no KA received for 120 s

Tolerance: Minimum KA 10 s

Stateful

Update capability

Instantiation capability

Segment Routing capability

KA messages rxed 1575 txed 1574

PCEReq messages rxed 0, txed 43

PCERep messages rxed 43, txed 0

PCEErr messages rxed 0, txed 0

Last error received: None

Last error sent: None

PCE OPEN messages: rxed 2, txed 2

PCERpt messages rxed 0, txed 11

PCEUpd messages rxed 3, txed 0

PCEInit messages rxed 0, txed 0

PCEP session ID: local 1, remote 0

Average reply time from peer: 28 ms

Minimum reply time from peer: 9 ms

Maximum reply time from peer: 299 ms

0 requests timed out with this peer

RP/0/0/CPU0:CORE-7#

From SRPCE checking valid path between CORE7 and CORE10

RP/0/0/CPU0:CORE-11-PCE#show pce ipv4 path source 7.0.0.1 des 10.0.0.1

Mon Nov 18 23:50:57.097 UTC

Path:

----:

Hop0: 10.5.7.2

Hop1: 10.1.5.2

Hop2: 10.1.4.1

Hop3: 10.4.8.1

Hop4: 10.8.10.1

RP/0/0/CPU0:CORE-11-PCE#show pce ipv4 peer

Mon Nov 18 23:51:30.465 UTC

PCE's peer database:

--------------------

Peer address: 7.0.0.1

State: Up

Capabilities: Stateful, Segment-Routing, Update, Instantiation

Peer address: 10.0.0.1

State: Up

Capabilities: Stateful, Segment-Routing, Update

If I create a manual tunnel on CORE7 for destination CORE10. It is coming up

RP/0/0/CPU0:CORE-7#show run int tunnel-te 100

Mon Nov 18 23:56:24.155 UTC

interface tunnel-te100

ipv4 unnumbered Loopback0

destination 10.0.0.1

path-option 1 dynamic pce segment-routing

!

RP/0/0/CPU0:CORE-7#show mpls traffic-eng tunnels

Mon Nov 18 23:57:13.052 UTC

Name: tunnel-te100 Destination: 10.0.0.1 Ifhandle:0xb0

Signalled-Name: CORE-7_t100

Status:

Admin: up Oper: up Path: valid Signalling: connected

path option 1, (Segment-Routing) type dynamic pce (Basis for Setup, path weight 50)

G-PID: 0x0800 (derived from egress interface properties)

Bandwidth Requested: 0 kbps CT0

Creation Time: Mon Nov 18 23:54:38 2019 (00:02:35 ago)

Config Parameters:

Bandwidth: 0 kbps (CT0) Priority: 7 7 Affinity: 0x0/0xffff

Metric Type: TE (global)

Path Selection:

Tiebreaker: Min-fill (default)

Protection: any (default)

Hop-limit: disabled

Cost-limit: disabled

Delay-limit: disabled

Path-invalidation timeout: 10000 msec (default), Action: Tear (default)

AutoRoute: disabled LockDown: disabled Policy class: not set

Forward class: 0 (not enabled)

Forwarding-Adjacency: disabled

Autoroute Destinations: 0

Loadshare: 0 equal loadshares

Auto-bw: disabled

Path Protection: Not Enabled

BFD Fast Detection: Disabled

Reoptimization after affinity failure: Enabled

SRLG discovery: Disabled

History:

Tunnel has been up for: 00:02:34 (since Mon Nov 18 23:54:39 UTC 2019)

Current LSP:

Uptime: 00:02:34 (since Mon Nov 18 23:54:39 UTC 2019)

Segment-Routing Path Info (PCE computed path)

Segment0[Node]: 6.0.0.1, Label: 16006

Segment1[Node]: 1.0.0.2, Label: 17001

Segment2[Node]: 3.0.0.1, Label: 16003

Segment3[Node]: 9.0.0.1, Label: 16009

Segment4[Node]: 10.0.0.1, Label: 16010

Displayed 1 (of 1) heads, 0 (of 0) midpoints, 0 (of 0) tails

Displayed 1 up, 0 down, 0 recovering, 0 recovered heads

RP/0/0/CPU0:CORE-7#show version brief
Tue Nov 19 00:08:28.586 UTC

ROM: GRUB, Version 1.99(0), DEV RELEASE

CORE-7 uptime is 1 day, 1 hour, 14 minutes
System image file is "bootflash:disk0/xrvr-os-mbi-6.4.2.16I/mbixrvr-rp.vm"

cisco IOS XRv Series (Pentium Celeron Stepping 3) processor with 3145215K bytes of memory.
Pentium Celeron Stepping 3 processor at 2453MHz, Revision 2.174
IOS XRv Chassis

1 Management Ethernet
3 GigabitEthernet
97070k bytes of non-volatile configuration memory.
866M bytes of hard disk.
2321392k bytes of disk0: (Sector size 512 bytes).
RP/0/0/CPU0:CORE-7#

samarjit dutta · ‎11-19-2019

One correction ....

In the explanation, by mistake i mentioned CORE11 as CORE10.
CORE11 is SRPCE and RR. CORE10 is PE

Elvin Arias · ‎11-19-2019

Nice setup you have over there ;)

Please post/do the following:

1. Make sure all your links are set to P2P in IS-IS topology first, XRTC can only compute paths (return EROs) for P2P links.
2. Post the "show bgp vrf <VRF>" and "show bgp vrf <VRF> <PREFIX> detail".

Elvin

samdutta · ‎11-19-2019

samarjit dutta · ‎11-19-2019

I have created one tunnel from PE1(CORE7) to PE2(CORE10) with the following CLIs. Such tunnel is up and out put of it available on original post. So I think XRPCE can find out the path between the PEs.

interface tunnel-te100
ipv4 unnumbered Loopback0
destination 10.0.0.1
path-option 1 dynamic pce segment-routing

output of manually created tunnel

RP/0/0/CPU0:CORE-7#show mpls traffic-eng tunnels
Mon Nov 18 23:57:13.052 UTC
Name: tunnel-te100  Destination: 10.0.0.1  Ifhandle:0xb0
  Signalled-Name: CORE-7_t100
  Status:
    Admin:    up Oper:   up   Path:  valid   Signalling: connected
    path option 1, (Segment-Routing) type dynamic pce (Basis for Setup, path weight 50)
    G-PID: 0x0800 (derived from egress interface properties)
    Bandwidth Requested: 0 kbps  CT0
    Creation Time: Mon Nov 18 23:54:38 2019 (00:02:35 ago)
  Config Parameters:
    Bandwidth:        0 kbps (CT0) Priority:  7  7 Affinity: 0x0/0xffff
    Metric Type: TE (global)
    Path Selection:
      Tiebreaker: Min-fill (default)
      Protection: any (default)
    Hop-limit: disabled
    Cost-limit: disabled
    Delay-limit: disabled
    Path-invalidation timeout: 10000 msec (default), Action: Tear (default)
    AutoRoute: disabled  LockDown: disabled   Policy class: not set
    Forward class: 0 (not enabled)
    Forwarding-Adjacency: disabled
    Autoroute Destinations: 0
    Loadshare:          0 equal loadshares
    Auto-bw: disabled
    Path Protection: Not Enabled
    BFD Fast Detection: Disabled
    Reoptimization after affinity failure: Enabled
    SRLG discovery: Disabled
  History:
    Tunnel has been up for: 00:02:34 (since Mon Nov 18 23:54:39 UTC 2019)
    Current LSP:
      Uptime: 00:02:34 (since Mon Nov 18 23:54:39 UTC 2019)
  Segment-Routing Path Info (PCE computed path)
    Segment0[Node]: 6.0.0.1, Label: 16006
    Segment1[Node]: 1.0.0.2, Label: 17001
    Segment2[Node]: 3.0.0.1, Label: 16003
    Segment3[Node]: 9.0.0.1, Label: 16009
    Segment4[Node]: 10.0.0.1, Label: 16010
Displayed 1 (of 1) heads, 0 (of 0) midpoints, 0 (of 0) tails
Displayed 1 up, 0 down, 0 recovering, 0 recovered heads

2ndly out put of show bgp vrf <VRF>" and "show bgp vrf <VRF> <PREFIX> detail". is very much same as show bgp vpnv4 unicast <prefix>

RP/0/0/CPU0:CORE-7#show bgp vrf A 20.200.0.1
Tue Nov 19 21:41:40.441 UTC
BGP routing table entry for 20.200.0.1/32, Route Distinguisher: 100:1
Versions:
  Process           bRIB/RIB  SendTblVer
  Speaker                 11          11
Last Modified: Nov 19 20:53:24.917 for 00:48:15
Paths: (1 available, no best path)
  Not advertised to any peer
  Path #1: Received by speaker 0
  Not advertised to any peer
  Local
    10.0.0.1 T:DEFAULT (inaccessible) from 11.0.0.1 (10.0.0.1)
      Received Label 24005
      Origin incomplete, metric 2, localpref 100, valid, internal, import-candidate, not-in-vrf
      Received Path ID 0, Local Path ID 0, version 0
      Extended community: OSPF route-type:0:1:0x0 OSPF router-id:20.13.10.1 RT:100:1
      Originator: 10.0.0.1, Cluster list: 11.0.0.1
      TE tunnel attribute-set DEFAULT, down, registered, bsid none, if-handle 0x00000000

RP/0/0/CPU0:CORE-7#show bgp vrf A 20.200.0.1/32 detail
Tue Nov 19 21:51:45.360 UTC
BGP routing table entry for 20.200.0.1/32, Route Distinguisher: 100:1
Versions:
  Process           bRIB/RIB  SendTblVer
  Speaker                 11          11
    Flags: 0x00040001+0x00000000;
Last Modified: Nov 19 20:53:24.917 for 00:58:20
Paths: (1 available, no best path)
  Not advertised to any peer
  Path #1: Received by speaker 0
  Flags: 0x4000000024020005, import: 0x00
  Not advertised to any peer
  Local
    10.0.0.1 T:DEFAULT (inaccessible) from 11.0.0.1 (10.0.0.1)
      Received Label 24005
      Origin incomplete, metric 2, localpref 100, valid, internal, import-candidate, not-in-vrf
      Received Path ID 0, Local Path ID 0, version 0
      Extended community: OSPF route-type:0:1:0x0 OSPF router-id:20.13.10.1 RT:100:1
      Originator: 10.0.0.1, Cluster list: 11.0.0.1
      TE tunnel attribute-set DEFAULT, down, registered, bsid none, if-handle 0x00000000

I cannot use wireshark in this network.

Like to identify whether PE sending any message to PCE for the path towards nexthop ?
Is the attribute set triggering communication with PCE

Is there any error in negotiation with PCE and PE during requesting the path ?