cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
782
Views
0
Helpful
7
Replies

Cisco 2821 high CPU with Multicast

Tshi M
Level 5
Level 5

I have two Cisco 2821 that I tried to use for MCAST but once MCAST traffic is enabled, the CPU goes to 98% and the HSRP process starts to flip flop between both routers. Could the 2821 routers be used for MCAST?

7 Replies 7

romccallum
Level 4
Level 4

on your interfaces do you have ip mroute-cache? if not try adding that - also make sure CEF is enabled.

yes, I do.

what is the bandwidth of the stream?

the problem seems to be with over subscriptions. We are dropping a significant number of packets once we turn on MCAST.

so all you are doing is configuring pim? No multicast flows? If you have a flow how much is the pps total? The reason i ask is i have destroyed a 7200-npe-g1 with a 1-10mb flow of multicast.

If I understand your question. Yes, I only have ip pim rp address and ip pim sparse-mode configured on the device.

Below is part of the sh int output after clearing the counters.

Last clearing of "show interface" counters 00:03:48

Input queue: 4/75/35053/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: fifo

Output queue: 0/40 (size/max)

5 minute input rate 3767000 bits/sec, 3667 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

1300612 packets input, 172618718 bytes, 0 no buffer

Received 1300319 broadcasts, 0 runts, 0 giants, 7825 throttles

I resolved the problem. The routers' CPU were clearly not able to handle multicast so I redesign the network to use the 3750G switches.

Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community:

Innovations in Cisco Full Stack Observability - A new webinar from Cisco