# BGP Conditional Advertising / Advertise MAP
**URL:** https://forum.networklessons.com/t/bgp-conditional-advertising-advertise-map/8631
**Category:** BGP
**Created:** [October 24, 2019, 2:16pm UTC](https://forum.networklessons.com/t/bgp-conditional-advertising-advertise-map/8631 "2019-10-24T14:16:55Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@raj7988](https://forum.networklessons.com/u/raj7988)
#### Post date: [October 24, 2019, 2:16pm UTC](https://forum.networklessons.com/t/bgp-conditional-advertising-advertise-map/8631/1 "2019-10-24T14:16:55Z")
Hello Rene
Please update the lesson on BGP Conditional Advertising / Advertise MAP.
If already in the lesson list, Please share the URL/Link.
regards
Raj
---
### Author:  [@lagapidis](https://forum.networklessons.com/u/lagapidis)
#### Post date: [October 25, 2019, 6:02am UTC](https://forum.networklessons.com/t/bgp-conditional-advertising-advertise-map/8631/2 "2019-10-25T06:02:42Z")
Hello Raj
As far as I know, there is no material yet on BGP conditional advertising. If you would like to suggest a lesson idea, feel free to go to the following link and post your idea. Others on the forum may have also suggested a similar lesson, and you can vote on the lessons you would like to see on the site in the near future.
> **[Lesson Ideas - NetworkLessons.com](https://networklessons.com/lesson-ideas)**
>
> This page allows networklessons members to share what content they would like to see in the future.
In the meantime, take a look at these two Cisco documentations that may help you in looking at this particular feature.
> **[Configure and Verify the BGP Conditional Advertisement Feature](https://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/16137-cond-adv.html)**
>
> This document describes how to configure and verify the Border Gateway Protocol (BGP) conditional advertisement feature.
As well as some case studies that may help…
> **[Examine Border Gateway Protocol Case Studies](https://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/26634-bgp-toc.html)**
>
> This document describes five Border Gateway Protocol (BGP) case studies.
I hope this has been helpful!
Laz
---
### Author:  [@nitayp1](https://forum.networklessons.com/u/nitayp1)
#### Post date: [November 3, 2019, 9:19am UTC](https://forum.networklessons.com/t/bgp-conditional-advertising-advertise-map/8631/3 "2019-11-03T09:19:52Z")
Hi raj,
the whole idea of Conditional advertising you could easly find the materials online.
it is used to play a role in multihomed architecture where you will only advertise routes to 1 ISP, if the link faills then the router sees the link down and immediately change to advertise the routes to the 2nd ISP.
you achieve this behavior using route-map and you inherit the route-map into the advertise-map in the bgp command options
for example:
```
access-list 1 permit host 1.1.1.1
access-list 2 permit any - this command is only an example
route-map NEIGHBOR1 permit 10
match ip address 1
route-map MYROUTES permit 10
match ip address 2
router bgp 1
neighbor 2.2.2.2 advertise-map MYROUTES non-exist-map NEIGHBOR1
```
in the above configuration, the router will check it’s RIB (routing table) and search the host route of 1.1.1.1 as included in the NEIGHBOR1 route-map.
the “non-exist-map” feature will make that process and if the route doesnt exist, the router would advertise neighbor 2.2.2.2 the “MYROUTES” routes included in that route-map.
you could specify any network you want to advertise or in this case I want to advertise everything to neighbor 2.2.2.2.
if the non-exist-map find the route for host 1.1.1.1 then the router wouldn’t advertise anything that included in the “MYROUTES” route-map to neighbor 2.2.2.2.