# Multicast PIM Accept RP **URL:** \ **Category:** Lessons Discussion\ **Created:** [December 26, 2016, 5:41pm UTC](https://forum.networklessons.com/t/multicast-pim-accept-rp/987 "2016-12-26T17:41:38Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![ReneMolenaar](https://cdn-forum.networklessons.com/user_avatar/forum.networklessons.com/renemolenaar/32/488_2.png) [@ReneMolenaar](https://forum.networklessons.com/u/ReneMolenaar)\ **Post date:** [December 26, 2016, 5:41pm UTC](https://forum.networklessons.com/t/multicast-pim-accept-rp/987/1 "2016-12-26T17:41:38Z")
This topic is to discuss the following lesson: > **[Multicast PIM Accept RP](https://networklessons.com/multicast/multicast-pim-accept-rp)** > > Multicast PIM Accept RP lets you configure what multicast groups your RP should accept or reject. ---
**Author:** ![wdavis84](https://cdn-forum.networklessons.com/letter_avatar_proxy/v4/letter/w/7ba0ec/32.png) [@wdavis84](https://forum.networklessons.com/u/wdavis84)\ **Post date:** [January 14, 2016, 3:58am UTC](https://forum.networklessons.com/t/multicast-pim-accept-rp/987/2 "2016-01-14T03:58:04Z")
Hi Rene, What is the different PIM accept RP and below configuration? The PIM accept RP applicable for static RP, Auto Rp and BSR? Ip PIM send-rp-annouce loopback 0 scope 10 group-list 1 Davis ---
**Author:** ![ReneMolenaar](https://cdn-forum.networklessons.com/user_avatar/forum.networklessons.com/renemolenaar/32/488_2.png) [@ReneMolenaar](https://forum.networklessons.com/u/ReneMolenaar)\ **Post date:** [January 14, 2016, 2:09pm UTC](https://forum.networklessons.com/t/multicast-pim-accept-rp/987/3 "2016-01-14T14:09:24Z")
Hi Davis, PIM accept RP can be used to tell your router not to accept just any RP. I believe it works for AutoRP and BSR, not for static RPs. For example when there are 10 routers in your network advertising themselves as the RP then you can use this command to ignore a couple of them. ip pim send-rp-announce is used to configure your router to advertise itself as an RP, the access-list is used to advertise the networks that you want to be a RP for. Rene ---
**Author:** ![wdavis84](https://cdn-forum.networklessons.com/letter_avatar_proxy/v4/letter/w/7ba0ec/32.png) [@wdavis84](https://forum.networklessons.com/u/wdavis84)\ **Post date:** [January 15, 2016, 2:11am UTC](https://forum.networklessons.com/t/multicast-pim-accept-rp/987/4 "2016-01-15T02:11:59Z")
Got it. Thanks Rene. Davis ---
**Author:** ![hansderoode](https://cdn-forum.networklessons.com/letter_avatar_proxy/v4/letter/h/35a633/32.png) [@hansderoode](https://forum.networklessons.com/u/hansderoode)\ **Post date:** [September 30, 2016, 8:36pm UTC](https://forum.networklessons.com/t/multicast-pim-accept-rp/987/5 "2016-09-30T20:36:12Z")
Hi Rene, Is 192.168.12.1 the address of the loopback of R1? Groeten, Hans. ---
**Author:** ![ReneMolenaar](https://cdn-forum.networklessons.com/user_avatar/forum.networklessons.com/renemolenaar/32/488_2.png) [@ReneMolenaar](https://forum.networklessons.com/u/ReneMolenaar)\ **Post date:** [October 11, 2016, 4:25pm UTC](https://forum.networklessons.com/t/multicast-pim-accept-rp/987/6 "2016-10-11T16:25:54Z")
Hi Hans, 192.168.12.1 is the IP address of R1. I usually use subnets / IP addresses like this: 192.168.XY.X where X = R1 and Y = R2. For loopbacks I use 1.1.1.1/32 for R1, 2.2.2.2/32 for R2 etc. Rene ---
**Author:** ![jamayassin](https://cdn-forum.networklessons.com/letter_avatar_proxy/v4/letter/j/bcef8e/32.png) [@jamayassin](https://forum.networklessons.com/u/jamayassin)\ **Post date:** [August 12, 2017, 1:32pm UTC](https://forum.networklessons.com/t/multicast-pim-accept-rp/987/7 "2017-08-12T13:32:27Z")
Hi Rene, What if I sourced the Multicast traffic from R1 Loopback, will it accept, for my lab its not accept and showing RPF failed or RP failed from debug, even though R2 has correc RPF. Regards Jam ---
**Author:** ![ReneMolenaar](https://cdn-forum.networklessons.com/user_avatar/forum.networklessons.com/renemolenaar/32/488_2.png) [@ReneMolenaar](https://forum.networklessons.com/u/ReneMolenaar)\ **Post date:** [August 18, 2017, 10:06am UTC](https://forum.networklessons.com/t/multicast-pim-accept-rp/987/8 "2017-08-18T10:06:17Z")
Hi Jam, It doesn’t matter if you use a loopback or “regular” interface as the source as long the RPF check is correct. It’s difficult to tell what is wrong without seeing your config. ---
**Author:** ![staut\_stefanita](https://cdn-forum.networklessons.com/user_avatar/forum.networklessons.com/staut_stefanita/32/1652_2.png) [@staut\_stefanita](https://forum.networklessons.com/u/staut_stefanita)\ **Post date:** [March 14, 2019, 6:41pm UTC](https://forum.networklessons.com/t/multicast-pim-accept-rp/987/9 "2019-03-14T18:41:44Z")
I believe the picture should be updated using 192.168.12.1 for R1 and .2 for R2. Thank you, Stefanita ---
**Author:** ![ReneMolenaar](https://cdn-forum.networklessons.com/user_avatar/forum.networklessons.com/renemolenaar/32/488_2.png) [@ReneMolenaar](https://forum.networklessons.com/u/ReneMolenaar)\ **Post date:** [March 28, 2019, 1:22pm UTC](https://forum.networklessons.com/t/multicast-pim-accept-rp/987/10 "2019-03-28T13:22:46Z")
Hi Stefanita, That’s right, thanks for letting us know. Just fixed this. Rene ---
**Author:** ![jaygk95](https://cdn-forum.networklessons.com/letter_avatar_proxy/v4/letter/j/77aa72/32.png) [@jaygk95](https://forum.networklessons.com/u/jaygk95)\ **Post date:** [February 18, 2020, 5:37pm UTC](https://forum.networklessons.com/t/multicast-pim-accept-rp/987/11 "2020-02-18T17:37:39Z")
Hi Rene, Your lab found at [https://gns3vault.com/multicast/multicast-pim-accept-rp](https://gns3vault.com/multicast/multicast-pim-accept-rp) is a better example of this exercise. The difference here that you used a standard ACL with the word “GROUPS” as opposed to numbers. Either way, thank you for both examples. Jay K. ---
**Author:** ![syedabrar\_8055](https://cdn-forum.networklessons.com/letter_avatar_proxy/v4/letter/s/50afbb/32.png) [@syedabrar\_8055](https://forum.networklessons.com/u/syedabrar_8055)\ **Post date:** [May 25, 2020, 3:11pm UTC](https://forum.networklessons.com/t/multicast-pim-accept-rp/987/12 "2020-05-25T15:11:53Z")
We will also need to allow 224.0.1.40 address, as this is used for RP. If not allowed below log is noticed. ``` R1# *Mar 1 01:41:51.139: %PIM-6-INVALID_RP_JOIN: Received (*, 224.0.1.40) Join from 192.168.12.2 for invalid RP 1.1.1.1 ``` ---
**Author:** ![lagapidis](https://cdn-forum.networklessons.com/user_avatar/forum.networklessons.com/lagapidis/32/4949_2.png) [@lagapidis](https://forum.networklessons.com/u/lagapidis)\ **Post date:** [May 28, 2020, 7:32am UTC](https://forum.networklessons.com/t/multicast-pim-accept-rp/987/13 "2020-05-28T07:32:59Z")
Hello Syed I tried labbing this up again, and after some time, I did get the same error message you mention. Even so the RP does appear correct in both routers. I will let Rene know to see if the lesson needs adding to… Thanks for pointing that out! Laz ---
**Author:** ![ReneMolenaar](https://cdn-forum.networklessons.com/user_avatar/forum.networklessons.com/renemolenaar/32/488_2.png) [@ReneMolenaar](https://forum.networklessons.com/u/ReneMolenaar)\ **Post date:** [May 28, 2020, 10:54am UTC](https://forum.networklessons.com/t/multicast-pim-accept-rp/987/14 "2020-05-28T10:54:00Z")
Hi Syed, 224.0.1.40 is for messages from the AutoRP mapping agent. We don’t need it here because we use a static RP. I think you can disable AutoRP now on Cisco IOS 15.x with the `no ip pim auto-rp` command. Rene ---
**Author:** ![syedabrar\_8055](https://cdn-forum.networklessons.com/letter_avatar_proxy/v4/letter/s/50afbb/32.png) [@syedabrar\_8055](https://forum.networklessons.com/u/syedabrar_8055)\ **Post date:** [June 8, 2020, 9:01pm UTC](https://forum.networklessons.com/t/multicast-pim-accept-rp/987/15 "2020-06-08T21:01:48Z")
Thanks for the reply ---
**Author:** ![stefriva](https://cdn-forum.networklessons.com/letter_avatar_proxy/v4/letter/s/7feea3/32.png) [@stefriva](https://forum.networklessons.com/u/stefriva)\ **Post date:** [November 12, 2021, 6:04pm UTC](https://forum.networklessons.com/t/multicast-pim-accept-rp/987/16 "2021-11-12T18:04:59Z")
Hi, I think also configs on R1 and R2 have to be modified as on eth0 shows 192.168.12.2 and 3 Thanks ---
**Author:** ![lagapidis](https://cdn-forum.networklessons.com/user_avatar/forum.networklessons.com/lagapidis/32/4949_2.png) [@lagapidis](https://forum.networklessons.com/u/lagapidis)\ **Post date:** [November 15, 2021, 8:08am UTC](https://forum.networklessons.com/t/multicast-pim-accept-rp/987/17 "2021-11-15T08:08:09Z")
Hello Stefano Yes, you are correct, I will let Rene know to make the changes… Thanks again! Laz ---
**Author:** ![samirkhair](https://cdn-forum.networklessons.com/letter_avatar_proxy/v4/letter/s/cdc98d/32.png) [@samirkhair](https://forum.networklessons.com/u/samirkhair)\ **Post date:** [May 19, 2025, 6:14pm UTC](https://forum.networklessons.com/t/multicast-pim-accept-rp/987/18 "2025-05-19T18:14:41Z")
Hi, I was reading some of the older replies and it seems there is an answer to a question I had: > [@Multicast PIM Accept RP](https://forum.networklessons.com/t/multicast-pim-accept-rp/987/2): > > Hi Rene, What is the different PIM accept RP and below configuration? The PIM accept RP applicable for static RP, Auto Rp and BSR? Ip PIM send-rp-annouce loopback 0 scope 10 group-list 1 Davis > [@Multicast PIM Accept RP](https://forum.networklessons.com/t/multicast-pim-accept-rp/987/3): > > Hi Davis, PIM accept RP can be used to tell your router not to accept just any RP. I believe it works for AutoRP and BSR, not for static RPs. For example when there are 10 routers in your network advertising themselves as the RP then you can use this command to ignore a couple of them. ip pim send-rp-announce is used to configure your router to advertise itself as an RP, the access-list is used to advertise the networks that you want to be a RP for. Rene But I just want to clarify that I understand it what is being said, which is that even though the lesson has applied the **accept-rp** command to the RP, it should actually be applied to the LHR - where there’s a receiver - to stop it from sending Joins to the RP in the first place. Is that correct? Thanks. Sam ---
**Author:** ![lagapidis](https://cdn-forum.networklessons.com/user_avatar/forum.networklessons.com/lagapidis/32/4949_2.png) [@lagapidis](https://forum.networklessons.com/u/lagapidis)\ **Post date:** [May 22, 2025, 5:32am UTC](https://forum.networklessons.com/t/multicast-pim-accept-rp/987/19 "2025-05-22T05:32:25Z")
Hello Sam > [@samirkhair](#): > > even though the lesson has applied the **accept-rp** command to the RP, it should actually be applied to the LHR - where there’s a receiver - to stop it from sending Joins to the RP in the first place. The accept-rp feature should be applied to any router that will potentially be an LHR. That can also include the RP, which is where it was applied in the lesson. In the lesson, this was used as an example to observe the behavior. Best practice dictates that you should apply it to any LHR where you want to control which RP is chosen. I hope this has been helpful! Laz ---
**Author:** ![samirkhair](https://cdn-forum.networklessons.com/letter_avatar_proxy/v4/letter/s/cdc98d/32.png) [@samirkhair](https://forum.networklessons.com/u/samirkhair)\ **Post date:** [October 10, 2025, 5:55pm UTC](https://forum.networklessons.com/t/multicast-pim-accept-rp/987/20 "2025-10-10T17:55:15Z")
Hi, Seeing as you have to configure accept-rp on every multicast router, what is the benefit of doing that over just statically configuring an RP instead (and disabling auto-rp)? Seems to achieve the same result and requires the same effort. Thanks, Sam [Next page](https://forum.networklessons.com/t/multicast-pim-accept-rp/987.md?page=2)