For you multicast pros out there...

NetworkGroover · January 14, 2016, 02:27:45 PM

Basic question. If you're looking to do an Anycast RP configuration, are you required to enable PIM on the loopback address you're going to use as the RP? My knowledge of multicast is abysmal.

wintermute000 · January 14, 2016, 02:52:43 PM

I have it in bold in my notes (ie turn it on) but for rp in general and I have no references LOL. But I can't see why any cast would differ or how it would hurt, esp on a look back and with igmp

DanC · January 14, 2016, 02:55:23 PM

It's just dawned on me... I did quite a lot of Multicast study and a bit of real life implementation about 12 Months ago, I've probably forgotten 90% of it now. That's depressing

I'm going to say YES but I could be wrong. I'm sure one our resident IE's will clear this up in a matter of seconds

^^^^ There you go...

NetworkGroover · January 14, 2016, 03:05:13 PM

Well, apparently I got some feedback on this and at least from one vendor's perspective it's not required. Just configure the loopback, point to it for desired groups, and enable PIM-SM on all mcast OIF/IIFs

dlots · January 14, 2016, 03:14:20 PM

We don't have it enabled

ip pim rp-address 10.128.1.16 acl-ipcp-rp-multicast

interface Loopback11
description Cell1_RP
ip address 10.128.1.16 255.255.255.255

NetworkGroover · January 14, 2016, 05:00:02 PM

Quote from: dlots on January 14, 2016, 03:14:20 PM
We don't have it enabled

ip pim rp-address 10.128.1.16 acl-ipcp-rp-multicast

interface Loopback11
description Cell1_RP
ip address 10.128.1.16 255.255.255.255

Thank you sir.

EDIT - Oh - what gear is that?

NetworkGroover · January 14, 2016, 05:05:10 PM

Quote from: DanC on January 14, 2016, 02:55:23 PM
It's just dawned on me... I did quite a lot of Multicast study and a bit of real life implementation about 12 Months ago, I've probably forgotten 90% of it now. That's depressing

I'm going to say YES but I could be wrong. I'm sure one our resident IE's will clear this up in a matter of seconds

^^^^ There you go...

This is me and QoS - funny how you become an expert when you're working on it then completely forget about it a few months later ;P

burnyd · January 14, 2016, 11:56:52 PM

Why would you need it enabled? I dont see the reason? You arent forwarding pim control traffic over it.

wintermute000 · January 15, 2016, 03:42:50 AM

You're right, but I remember having issues labbing until I did. However at that time gns3 (3700 images on old school, not iosv) was full of multicast bugs. I think I just got into the habit of spraying pim everywhere just in case.

dlots · January 15, 2016, 09:31:43 AM

That is 1900, 2900s, and 3900s, (ISRG2s)

NetworkGroover · January 15, 2016, 10:29:02 AM

Quote from: wintermute000 on January 15, 2016, 03:42:50 AM
You're right, but I remember having issues labbing until I did. However at that time gns3 (3700 images on old school, not iosv) was full of multicast bugs. I think I just got into the habit of spraying pim everywhere just in case.

Well on top of that, when I looked at a Cisco example of how to configure Anycast RP, I think they had it configured.

dlots · January 28, 2016, 09:46:30 AM

I was digging into anycast more yesterday and at least for some platforms you do need it according to my CCIE materials, but we don't seem to.

if you get an error saying saying I got a *,g or a s,g register and I won't be an RP that's what it looks like if you need it and don't have it.

it looks like the error would look like this.
PIM-6-INVALID_RP_JOIN: Recived (*,224.0.1.40) Join from 155.1.45.5 for invalid RP 150.1.1.1

NetworkGroover · January 28, 2016, 10:23:57 AM

Quote from: dlots on January 28, 2016, 09:46:30 AM
I was digging into anycast more yesterday and at least for some platforms you do need it according to my CCIE materials, but we don't seem to.

if you get an error saying saying I got a *,g or a s,g register and I won't be an RP that's what it looks like if you need it and don't have it.

it looks like the error would look like this.
PIM-6-INVALID_RP_JOIN: Recived (*,224.0.1.40) Join from 155.1.45.5 for invalid RP 150.1.1.1

Heh... yeah.. not surprised. If there's one thing I've learned recently it's that 100% feature parity is also a bit of a unicorn. Particularly between different ASICs and single-chip vs. multi-chip, but then add in different network operating systems (Cisco), and it's really hard for an engineer to keep things straight.. at least dumb ones like myself.

wintermute000 · January 28, 2016, 04:17:13 PM

phew, for a moment there I thought my answer was 100% wrong, thanks for giving me an out

I still agree with burnyd's theoretical answer but there must have been a good reason why I wrote what I did in my notes!