I have a scenario I am trying to get an explanation to regarding 2 PIM DR's running as anycast RP's attached to a LAN. Basically I cannot understand how PIM,IGMP operates in the scenario below with the respect to the forwarding of source traffic from a multi-access segment. The PIM standard states that the DR will forward traffic onto and off a multi-access segment, but in the scenario below the non-dr takes over the forwarding of source traffic from the multi-access segment, when link A fails. Can anyone explain what PIM is doing is this scenario as I cannot see any procedural details in the PIM standard.
Thanks in advance
In the following scenario when both A and B links are available both the source tree and the shared tree are built along link A.
|Pigpen | ip igmp join-group
/ A \B
------------- ------------ R 126.96.36.199
|Maggie | MSDP | Lisa | 188.8.131.52
10.159.71.194 | DR|10.159.71.193
Source to 184.108.40.206
The PIM standard states that a DR will forward traffic onto and off a LAN. In the scenario above, the DR Maggie will forward traffic from its Ethernet interface and out of link A.
Often times complex troubleshooting issues are best addressed in an interactive session with one of our trained technical assistance engineers. While other forum users may be able to help, its often difficult to do so for this type of issue.
Alright, I will see if I can sort this out. The picture that you drew did not come through such that I can read it. (It all collapsed, I think the days of ASCII art are dying unfortunately.)
Alright, so we have both Lisa and Maggie who are connected to the Ethernet segment C.
They each have a serial link to Pigpen. Lisa is connected to Pigpen via link B, Maggie is connected to Pigpen via Link A.
When Link A fails, Maggie now finds that she now has an empty OIL for group 220.127.116.11. This means that Maggie will PRUNE the incoming interface, as she no longer needs the traffic. However, Pigpen will have noticed the link failure to Maggie and will have send a JOIN to Lisa. Lisa will see Maggie's PRUNE on Link C and will send a JOIN on Link C to counter the PRUNE. Lisa will be the new DR because Maggie has pruned off the incoming flow and is not sending any PIM messages out that interface. (Remember JOINs and PRUNEs are the same message really JOIN/PRUNE, but I treated them as separate messages for the sake of this discussion)
If I have mis-interpreted your question, please feel free to clarify. I did not deal with some of the additional complexities that may be involved based on these being RP's, but I don't feel they are relevant.
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.