Troubleshoot OMP Best Path Selection Peculiarities and Typical Confusions
Available Languages
Download Options
Bias-Free Language
The documentation set for this product strives to use bias-free language. For the purposes of this documentation set, bias-free is defined as language that does not imply discrimination based on age, disability, gender, racial identity, ethnic identity, sexual orientation, socioeconomic status, and intersectionality. Exceptions may be present in the documentation due to language that is hardcoded in the user interfaces of the product software, language used based on RFP documentation, or language that is used by a referenced third-party product. Learn more about how Cisco is using Inclusive Language.
Contents
Introduction
This document describes how to troubleshoot the OMP best-path selection and operation between the OMP, egress policy, and send-path-limit feature.
Prerequisites
Requirements
Cisco recommends that you have knowledge of the Cisco Software Defined Wide Area Network (SDWAN) solution.
Components Used
The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, ensure that you understand the potential impact of any command.
Background Information
For the purpose of this demonstration, the lab was set up with three vSmart controllers and three Cisco IOS® XE routers with sites IDs 243, 244, and 245 advertising the same 172.16.1.0/24 prefix. There are also some other routers connected to the overlay (for example, with site-id 204). The last octet of any router system-ip is equal to site-id in this example (10.10.10.<site-id>). vSmarts are having system-ip 10.10.10.228, .229, and .230. In this example, each router has two transports (WAN interfaces) available hence two Transport Locators (TLOCs) with colors private1 and biz-internet. On private1, the circuit router has an IP address assigned in the form of 192.168.9.x and on biz-internet it has 192.168.10.x where x is a site-id.
Scenarios were tested with vSmarts running software versions 20.4.1 and 20.6.1.
Best Path Selection, Egress Policy and Send-Path Limit Order of Operations
First of all, demonstrate the best path selection, egress policy, and send-path-limit order of operations. Routers with site-id 247 must receive prefix from routers with site-id 244 or 245, but not from 243.
Here is the policy to achieve this for reference:
policy
lists
site-list site_247
site-id 247
!
site-list sites_244_245
site-id 244
site-id 245
!
prefix-list ENK_PL
ip-prefix 172.16.1.0/24
!
!
control-policy send_2_247
sequence 10
match route
prefix-list ENK_PL
site-list sites_244_245
!
action accept
!
!
sequence 20
match route
prefix-list ENK_PL
!
action reject
!
!
default-action accept
!
!
apply-policy
site-list site_247
control-policy send_2_247 out
!
!When you take a look a vSmart2, it has connectivity to two other vSmarts (site-id 1) and edge routers with site-id 243, 244, and 247. Site 245 is connected to some other vSmart controller and vSmart2 receives its prefix from them indirectly via other vSmart(s).
vsmart2# show omp peers
R -> routes received
I -> routes installed
S -> routes sent
DOMAIN OVERLAY SITE
PEER TYPE ID ID ID STATE UPTIME R/I/S
------------------------------------------------------------------------------------------
10.10.10.204 vedge 1 1 204 up 2:20:18:10 14/0/7
10.10.10.228 vsmart 1 1 1 up 2:20:18:06 247/0/9
10.10.10.230 vsmart 1 1 1 up 2:20:17:07 256/0/15
10.10.10.243 vedge 1 1 243 up 2:20:18:10 8/0/7
10.10.10.244 vedge 1 1 244 up 0:13:24:59 10/0/6
10.10.10.247 vedge 1 1 247 up 2:20:18:10 0/0/8
In the OMP table, you can notice that route is being received from two other vSmart controllers and also directly from sites 243 and 244:
vsmart2# show omp routes 172.16.1.0/24
Code:
C -> chosen
I -> installed
Red -> redistributed
Rej -> rejected
L -> looped
R -> resolved
S -> stale
Ext -> extranet
Inv -> invalid
Stg -> staged
IA -> On-demand inactive
U -> TLOC unresolved
PATH ATTRIBUTE
VPN PREFIX FROM PEER ID LABEL STATUS TYPE TLOC IP COLOR ENCAP PREFERENCE
--------------------------------------------------------------------------------------------------------------------------------------
1 172.16.1.0/24 10.10.10.228 409 1001 C,R installed 10.10.10.243 public-internet ipsec -
10.10.10.230 7187 1002 C,R installed 10.10.10.244 biz-internet ipsec -
10.10.10.243 69 1001 C,R installed 10.10.10.243 public-internet ipsec -
10.10.10.243 81 1001 C,R installed 10.10.10.243 private1 ipsec -
10.10.10.244 68 1002 C,R installed 10.10.10.244 biz-internet ipsec -
10.10.10.244 81 1002 C,R installed 10.10.10.244 private1 ipsec -send-path-limit - in this demonstration is set to 1:
vsmart2# show running-config omp
omp
no shutdown
send-path-limit 1
no graceful-restart
!
Note: From all equal-cost multi-paths for given prefix selected as best-paths and accepted by outbound (egress) policy, not more than the number of paths specified in send-path-limit advertised.
You can check which prefix is advertised to which peer. The route originated by site 243 has the lowest originator system-ip in the OMP route list. Because send-path-limit is set to 1, out of two available paths via TLOC private1 and biz-internet, the only route advertised to the routers with site-id 204 and 244 as well as to two other vSmart controllers (10.10.10.228, .230) is from the biz-internet TLOC because it has a highest private IP address (address assigned to the interface):
vsmart2# show omp tlocs ip 10.10.10.243 received | b PUBLIC
ADDRESS PSEUDO PUBLIC PRIVATE
FAMILY TLOC IP COLOR ENCAP FROM PEER STATUS KEY PUBLIC IP PORT PRIVATE IP PORT
------------------------------------------------------------------------------------------------------------------------
ipv4 10.10.10.243 biz-internet ipsec 10.10.10.228 C,R 1 192.168.10.243 12346 192.168.10.243 12346
10.10.10.230 C,R 1 192.168.10.243 12346 192.168.10.243 12346
10.10.10.243 C,I,R 1 192.168.10.243 12346 192.168.10.243 12346
10.10.10.243 private1 ipsec 10.10.10.228 C,R 1 192.168.9.243 12346 192.168.9.243 12346
10.10.10.230 C,R 1 192.168.9.243 12346 192.168.9.243 12346
10.10.10.243 C,I,R 1 192.168.9.243 12346 192.168.9.243 12346Site id 243 gets the next route from the list (from site 244) and it is also via biz-internet color because it has the highest TLOC private IP address. Site 243 does not get its own route because of the split-horizon rule though it has the lowest system-IP. Site 247 gets the route from site 244 as well because of the egress policy.
vsmart2# show omp routes 172.16.1.0/24 detail | nomore | exclude not\ set | b ADVERTISED | include peer\|originator\|tloc
peer 10.10.10.204
originator 10.10.10.243
tloc 10.10.10.243, biz-internet, ipsec
peer 10.10.10.228
originator 10.10.10.243
tloc 10.10.10.243, biz-internet, ipsec
peer 10.10.10.230
originator 10.10.10.243
tloc 10.10.10.243, biz-internet, ipsec
peer 10.10.10.243
originator 10.10.10.244
tloc 10.10.10.244, biz-internet, ipsec
peer 10.10.10.244
originator 10.10.10.243
tloc 10.10.10.243, biz-internet, ipsec
peer 10.10.10.247
originator 10.10.10.244
tloc 10.10.10.244, biz-internet, ipsec
vSmart Best Path Selection: Edge Router Sourced Routes vs Routes Received via Other vSmarts Case 1
In order to continue this demonstration, increase send-path-limit and set it to 16, enable debug omp policy prefix 172.16.1.0/24 level high, and observe the results. Now, vSmart2 also receives a route from site-id 245 via vSmart1 with system-ip 10.10.10.228 and vSmart3 with 10.10.10.230).
vsmart2# show omp routes 172.16.1.0/24
Code:
C -> chosen
I -> installed
Red -> redistributed
Rej -> rejected
L -> looped
R -> resolved
S -> stale
Ext -> extranet
Inv -> invalid
Stg -> staged
IA -> On-demand inactive
U -> TLOC unresolved
PATH ATTRIBUTE
VPN PREFIX FROM PEER ID LABEL STATUS TYPE TLOC IP COLOR ENCAP PREFERENCE
--------------------------------------------------------------------------------------------------------------------------------------
1 172.16.1.0/24 10.10.10.228 10146 1001 C,R installed 10.10.10.243 public-internet ipsec -
10.10.10.228 10448 1001 C,R installed 10.10.10.243 private1 ipsec -
10.10.10.228 10449 1002 C,R installed 10.10.10.245 biz-internet ipsec -
10.10.10.228 10450 1002 C,R installed 10.10.10.245 private1 ipsec -
10.10.10.230 10252 1002 C,R installed 10.10.10.244 biz-internet ipsec -
10.10.10.230 10577 1002 C,R installed 10.10.10.244 private1 ipsec -
10.10.10.230 10578 1002 C,R installed 10.10.10.245 biz-internet ipsec -
10.10.10.230 10579 1002 C,R installed 10.10.10.245 private1 ipsec -
10.10.10.243 69 1001 C,R installed 10.10.10.243 public-internet ipsec -
10.10.10.243 81 1001 C,R installed 10.10.10.243 private1 ipsec -
10.10.10.244 68 1002 C,R installed 10.10.10.244 biz-internet ipsec -
10.10.10.244 81 1002 C,R installed 10.10.10.244 private1 ipsec -But vSmart2 advertises only routes from site 244, and not from 245, to site 247 now. This is a typical source of confusion because routes received directly from edge routers are preferred over routes received via vSmarts and not advertised to an Edge router and not sent to an Edge router, but only in case if vSmart found an OMP routing table entry for the same prefix from any other vSmart that Edge router is already connected to:
vsmart2# show omp routes 172.16.1.0/24 detail | nomore | exclude not\ set | b ADVERTISED | include peer\|originator
peer 10.10.10.204
originator 10.10.10.244
originator 10.10.10.244
originator 10.10.10.243
originator 10.10.10.243
peer 10.10.10.228
originator 10.10.10.244
originator 10.10.10.244
originator 10.10.10.243
originator 10.10.10.243
peer 10.10.10.230
originator 10.10.10.244
originator 10.10.10.244
originator 10.10.10.243
originator 10.10.10.243
peer 10.10.10.243
originator 10.10.10.244
originator 10.10.10.244
peer 10.10.10.244
originator 10.10.10.243
originator 10.10.10.243
peer 10.10.10.247
originator 10.10.10.244
originator 10.10.10.244
This is also confirmed from debug logs stored in /var/log/tmplog/vdebug where the reason for suppression is seen as vSmart Connectivity.
Oct 9 14:29:01 vsmart2 OMPD[1120]: omp_rib_out_process_entry[3792]: Peer: 10.10.10.247 NLRI: 1: 172.16.1.0/24 from 10.10.10.243 Path: 69 suppressed due to - Policy Rejection
Oct 9 14:29:01 vsmart2 OMPD[1120]: omp_rib_out_process_entry[3792]: Peer: 10.10.10.247 NLRI: 1: 172.16.1.0/24 from 10.10.10.243 Path: 81 suppressed due to - Policy Rejection
Oct 9 14:29:01 vsmart2 OMPD[1120]: omp_rib_out_process_entry[3792]: Peer: 10.10.10.247 NLRI: 1: 172.16.1.0/24 from 10.10.10.228 Path: 11005 suppressed due to - vSmart Connectivity
Oct 9 14:29:01 vsmart2 OMPD[1120]: omp_rib_out_process_entry[3792]: Peer: 10.10.10.247 NLRI: 1: 172.16.1.0/24 from 10.10.10.228 Path: 11006 suppressed due to - vSmart Connectivity
Oct 9 14:29:01 vsmart2 OMPD[1120]: omp_rib_out_process_entry[3792]: Peer: 10.10.10.247 NLRI: 1: 172.16.1.0/24 from 10.10.10.228 Path: 11007 suppressed due to - vSmart Connectivity
Oct 9 14:29:01 vsmart2 OMPD[1120]: omp_rib_out_process_entry[3792]: Peer: 10.10.10.247 NLRI: 1: 172.16.1.0/24 from 10.10.10.228 Path: 11008 suppressed due to - vSmart Connectivity
Oct 9 14:29:01 vsmart2 OMPD[1120]: omp_rib_out_process_entry[3792]: Peer: 10.10.10.247 NLRI: 1: 172.16.1.0/24 from 10.10.10.230 Path: 11186 suppressed due to - vSmart Connectivity
Oct 9 14:29:01 vsmart2 OMPD[1120]: omp_rib_out_process_entry[3792]: Peer: 10.10.10.247 NLRI: 1: 172.16.1.0/24 from 10.10.10.230 Path: 11187 suppressed due to - vSmart Connectivity
At the same time, keep in mind that site 247 receives both routes finally anyway, because by default it is connected to two vSmart controllers (max-control-connections 2) and vSmart3 advertises both routes to it because originators are directly connected to it:
Site-247#show sdwan omp routes 172.16.1.0/24 | begin PATH
PATH ATTRIBUTE
VPN PREFIX FROM PEER ID LABEL STATUS TYPE TLOC IP COLOR ENCAP PREFERENCE
--------------------------------------------------------------------------------------------------------------------------------------
1 172.16.1.0/24 10.10.10.229 13 1002 C,I,R installed 10.10.10.244 biz-internet ipsec -
10.10.10.229 14 1002 C,I,R installed 10.10.10.244 private1 ipsec -
10.10.10.230 13 1002 C,R installed 10.10.10.244 biz-internet ipsec -
10.10.10.230 14 1002 C,R installed 10.10.10.244 private1 ipsec -
10.10.10.230 61 1002 C,I,R installed 10.10.10.245 biz-internet ipsec -
10.10.10.230 62 1002 C,I,R installed 10.10.10.245 private1 ipsec -vsmart3# show omp routes 172.16.1.0/24 detail | nomore | exclude not\ set | b ADVERTISED | include peer\|originator | b "peer 10.10.10.247"
peer 10.10.10.247
originator 10.10.10.244
originator 10.10.10.244
originator 10.10.10.245
originator 10.10.10.245A summarization of the best path selection and order of operations in included in this table.
|
1. Prefer non-stale route over stale route |
|
2. Route resolvability Next-hop TLOC is Reachable (data plane BFD session is here) |
|
3. Prefer highest route preference |
|
4. Prefer highest TLOC preference |
|
5. Prefer best origin code (Connected, Static, eBGP, EIGRP Internal, OSPF Intra, OSPF Inter, OSPF External, EIGRP External iBGP, Unknown/Unset) |
|
6. Route Source Preference. On vSmart: prefer Edge router-sourced route over vSmart-sourced route |
|
7. Prefer OMP route with lowest origin metric |
|
8. Prefer route received from lowest System-IP |
|
9. Prefer route from highest Private TLOC IP-address originated from the same site-id |
|
10. outbound control policy |
|
11. send-path-limit |
vSmart Best Path Selection: Edge Router Sourced Routes vs Routes Received via Other vSmarts Case 2
This behavior can be seen in double-failure scenarios with controllers affinity configuration and outbound (egress) policy configuration that discriminates some routes from some sources over others based on some criteria as we do with policy in the previous scenarios. For the purpose of demonstration in this section, you need to increase route scale compared to the previous scenarios, so more sites with different site-ids are used. Consider typical deployment with three vSmart controllers and three geographical regions just like in the demonstration in the previous section. With help of affinity, each vSmart is assigned to the corresponding group 1, 2, or 3. max-control-connections is set to the default value of 2. vSmarts 1 and 2 are preferred for routers from region A. In region B vSmart 2 and 3 are preferred. For a region, C vSmart 3 and 1 are preferred.
Here is an example of configuration to assign vSmart controller to Group 1:
system
controller-group-id 1
!
And also, an example of a configuration for the router from region A that prefers controllers from Groups 1 and 2. Controllers from Group 3 are used as a last resort to connect if none of the controllers from Groups 1 and 2 are available because max-control-connections is set to 2 by default:
system
controller-group-list 1 2 3
!
The same result can be achieved with the other configuration:
vpn 0
interface ge0/0
tunnel-interface
exclude-controller-group-list 3
!
!
!
max-control-connections is also set to a default value of 2 in this demonstration. send-path-limit set to value 16 on all routers and controllers.
Each region has 2 routers now originating prefix 10.0.0.0/8. Each of those routers has five transports (WAN interfaces) with TLOC colors from private1 to private5. cEdges originating this prefix are assigned to the regions as shown in this table. It also describes new system-ip addressing.
|
hostname / system-ip |
vSmart1 |
vSmart2 |
vSmart3 |
|
|
169.254.206.4 |
169.254.206.5 |
169.254.206.6 |
||
|
cEdge1 |
169.254.206.11 |
Region A |
Region A |
|
|
cEdge2 |
169.254.206.12 |
Region A |
Region A |
|
|
cEdge3 |
169.254.206.13 |
Region B |
Region B |
|
|
cEdge4 |
169.254.206.14 |
Region B |
Region B |
|
|
cEdge5 |
169.254.206.15 |
Region C |
Region C |
|
|
cEdge6 |
169.254.206.16 |
Region C |
Region C |
|
Such configuration and scale mean that each vSmart controller receives 20 paths from directly connected routers (4 router x 5 TLOCs) and in addition also 20 paths from each vSmart. In total, it gives 60 paths for the given prefix 10.0.0.0/8 in the OMP table of each vSmart controller in normal conditions. Some unimportant columns were removed from show omp route 10.0.0.0/8 vSmart1 output for brevity.
FROM PEER STATUS TLOC IP COLOR PREFERENCE
------------------------------------------------------------------
169.254.206.5 C,R 169.254.206.11 private1 -
169.254.206.5 C,R 169.254.206.11 private2 -
169.254.206.5 C,R 169.254.206.11 private3 -
169.254.206.5 C,R 169.254.206.11 private4 -
169.254.206.5 C,R 169.254.206.11 private5 -
169.254.206.5 C,R 169.254.206.12 private1 -
169.254.206.5 C,R 169.254.206.12 private2 -
169.254.206.5 C,R 169.254.206.12 private3 -
169.254.206.5 C,R 169.254.206.12 private4 -
169.254.206.5 C,R 169.254.206.12 private5 -
169.254.206.5 C,R 169.254.206.13 private1 -
169.254.206.5 C,R 169.254.206.13 private2 -
169.254.206.5 C,R 169.254.206.13 private3 -
169.254.206.5 C,R 169.254.206.13 private4 -
169.254.206.5 C,R 169.254.206.13 private5 -
169.254.206.5 C,R 169.254.206.14 private1 -
169.254.206.5 C,R 169.254.206.14 private2 -
169.254.206.5 C,R 169.254.206.14 private3 -
169.254.206.5 C,R 169.254.206.14 private4 -
169.254.206.5 C,R 169.254.206.14 private5 -
169.254.206.6 C,R 169.254.206.13 private1 -
169.254.206.6 C,R 169.254.206.13 private2 -
169.254.206.6 C,R 169.254.206.13 private3 -
169.254.206.6 C,R 169.254.206.13 private4 -
169.254.206.6 C,R 169.254.206.13 private5 -
169.254.206.6 C,R 169.254.206.14 private1 -
169.254.206.6 C,R 169.254.206.14 private2 -
169.254.206.6 C,R 169.254.206.14 private3 -
169.254.206.6 C,R 169.254.206.14 private4 -
169.254.206.6 C,R 169.254.206.14 private5 -
169.254.206.6 C,R 169.254.206.15 private1 -
169.254.206.6 C,R 169.254.206.15 private2 -
169.254.206.6 C,R 169.254.206.15 private3 -
169.254.206.6 C,R 169.254.206.15 private4 -
169.254.206.6 C,R 169.254.206.15 private5 -
169.254.206.6 C,R 169.254.206.16 private1 -
169.254.206.6 C,R 169.254.206.16 private2 -
169.254.206.6 C,R 169.254.206.16 private3 -
169.254.206.6 C,R 169.254.206.16 private4 -
169.254.206.6 C,R 169.254.206.16 private5 -
169.254.206.11 C,R 169.254.206.11 private1 -
169.254.206.11 C,R 169.254.206.11 private2 -
169.254.206.11 C,R 169.254.206.11 private3 -
169.254.206.11 C,R 169.254.206.11 private4 -
169.254.206.11 C,R 169.254.206.11 private5 -
169.254.206.12 C,R 169.254.206.12 private1 -
169.254.206.12 C,R 169.254.206.12 private2 -
169.254.206.12 C,R 169.254.206.12 private3 -
169.254.206.12 C,R 169.254.206.12 private4 -
169.254.206.12 C,R 169.254.206.12 private5 -
169.254.206.15 C,R 169.254.206.15 private1 -
169.254.206.15 C,R 169.254.206.15 private2 -
169.254.206.15 C,R 169.254.206.15 private3 -
169.254.206.15 C,R 169.254.206.15 private4 -
169.254.206.15 C,R 169.254.206.15 private5 -
169.254.206.16 C,R 169.254.206.16 private1 -
169.254.206.16 C,R 169.254.206.16 private2 -
169.254.206.16 C,R 169.254.206.16 private3 -
169.254.206.16 C,R 169.254.206.16 private4 -
169.254.206.16 C,R 169.254.206.16 private5 -
Now let us discuss a failure scenario. Some spoke routers with site-id 20 that belong to Region A cannot connect to both controllers, for whatever reason, and are connected to only one controller vSmart3 which is the last resort vSmart for this region.
Site-20# show omp peers
R -> routes received
I -> routes installed
S -> routes sent
DOMAIN OVERLAY SITE
PEER TYPE ID ID ID STATE UPTIME R/I/S
------------------------------------------------------------------------------------------
169.254.206.6 vsmart 1 1 1 up 0:00:26:31 10/4/0
If no control-policy is configured, this can lead to suboptimal routing for Site-20 from Region A because as per the best-path selection algorithm, vSmart3 advertises routes received from Edge routers first. They are more preferred than routes native to region A received via vSmart controllers vSmart1 and vSmart2:
vsmart3# show omp routes 10.0.0.0/8 advertised detail | nomore | b ADVERTISED | i originator\|peer\|\ tloc | b “peer 192.168.206.20”
peer 192.168.206.20
originator 169.254.206.14
tloc 169.254.206.14, private2, ipsec
originator 169.254.206.14
tloc 169.254.206.14, private1, ipsec
originator 169.254.206.14
tloc 169.254.206.14, private3, ipsec
originator 169.254.206.14
tloc 169.254.206.14, private4, ipsec
originator 169.254.206.14
tloc 169.254.206.14, private5, ipsec
originator 169.254.206.15
tloc 169.254.206.15, private5, ipsec
originator 169.254.206.15
tloc 169.254.206.15, private2, ipsec
originator 169.254.206.15
tloc 169.254.206.15, private1, ipsec
originator 169.254.206.15
tloc 169.254.206.15, private3, ipsec
originator 169.254.206.15
tloc 169.254.206.15, private4, ipsec
originator 169.254.206.13
tloc 169.254.206.13, private5, ipsec
originator 169.254.206.13
tloc 169.254.206.13, private4, ipsec
originator 169.254.206.13
tloc 169.254.206.13, private3, ipsec
originator 169.254.206.13
tloc 169.254.206.13, private1, ipsec
originator 169.254.206.13
tloc 169.254.206.13, private2, ipsec
originator 169.254.206.16
tloc 169.254.206.16, private1, ipsec
In order to avoid suboptimal routing, vSmart must allow spokes to receive routes from the routers in the same region only. Here is an example of a control policy to achieve this result:
policy
lists
site-list hubs_A
site-id 11
site-id 12
!
site-list hubs_B
site-id 13
site-id 14
!
site-list hubs_C
site-id 15
site-id 16
!
site-list spokes_A
site-id 20
!
site-list spokes_B
site-id 21
!
site-list spokes_C
site-id 10
!
!
control-policy region_A
sequence 10
match route
site-list hubs_A
!
action accept
!
!
sequence 20
match route
!
action reject
!
!
default-action accept
!
control-policy region_B
sequence 10
match route
site-list hubs_B
!
action accept
!
!
sequence 20
match route
!
action reject
!
!
default-action accept
!
control-policy region_C
sequence 10
match route
site-list hubs_C
!
action accept
!
!
sequence 20
match route
!
action reject
!
!
default-action accept
!
!
apply-policy
site-list spokes_A
control-policy region_A out
!
site-list spokes_B
control-policy region_B out
!
site-list spokes_C
control-policy region_C out
!
!
But from the previous scenario, you know that Edge-sourced routes are preferred over routes received via vSmart controllers. Does it mean that Site-20 in current conditions cannot receive any routes?
Here is yet another important concept that is being missed frequently. Routes from cEdge1 and cEdge2 (system-ip 169.254.206.11 and 169.254.206.12) are though kept in vSmart3 OMP table even if they are less preferred and still marked as C (“chosen”). All steps in the best-path selection algorithm starting from step 8 (including) considered tie-breakers and routes are not removed from the OMP table, but sorted according to the described preference for the purpose of consequent processing by egress control policies and send-path-limit limitation.
Because vSmart3 cannot find an OMP routing table entry for the refix 10.0.0.0/8 from other vSmart that Edge router is already connected to (Site-20 connected to vSmart3 only), it advertises routes from site 11 and site 12 (cEdge1 and cEdge2 correspondingly) to the site 20 router:
vsmart3# show omp routes 10.0.0.0/8 advertised detail | nomore | b ADVERTISED | i originator\|peer\|\ tloc | b “peer 192.168.206.20”
peer 192.168.206.20
originator 169.254.206.11
tloc 169.254.206.11, private1, ipsec
originator 169.254.206.11
tloc 169.254.206.11, private2, ipsec
originator 169.254.206.11
tloc 169.254.206.11, private3, ipsec
originator 169.254.206.11
tloc 169.254.206.11, private4, ipsec
originator 169.254.206.11
tloc 169.254.206.11, private5, ipsec
originator 169.254.206.12
tloc 169.254.206.12, private1, ipsec
originator 169.254.206.12
tloc 169.254.206.12, private2, ipsec
originator 169.254.206.12
tloc 169.254.206.12, private3, ipsec
originator 169.254.206.12
tloc 169.254.206.12, private4, ipsec
originator 169.254.206.12
tloc 169.254.206.12, private5, ipsec
Related Information
Revision History
| Revision | Publish Date | Comments |
|---|---|---|
3.0 |
23-Aug-2024 |
Shortened introduction and corrected 'will' |
2.0 |
26-Oct-2021 |
Initial Release |
1.0 |
27-Oct-2021 |
Initial Release |
Contributed by
- Eugene KhabarovCisco Engineering
FeedbackContact Cisco
- Open a Support Case
- (Requires a Cisco Service Contract)