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New Member

Routing advice

I am in the process to change our Catalyst 5500 with RSM to Catalyst 6509 (SUP2 + MSFC2) this week end and I have these question:

1) When copying the configuration from RSM on Catalyst 5500 to Catalyst 6509, I got these messages:

=> WARNING: "ip multicast-routing" is not configured, IP Multicast packets will not be forwarded.

=> %SYS-5-CONFIG_I: Configured from tftp://

june03.cfg by vty0 ( Jun 17 09:46:47 PST -08:00 %MCAST-2-IGMPV3_DISABLED:IGMPV3: Disabling IGMPV3 processing since MMLS was enabled on MSFC

Did I need to enable multicast-routing/IGMPV3 ?

2) On the RSM on Catalyst 5500 we have this configuration:

ip cef

interface vlan xxx

no ip route-cache cef

no ip redirect

Do I need to enable ip route-cache cef and what is the global command on Catalyst 6509 (ip cef ?????)



Running Hybrid mode on Catalyst 6509 (MSFC2 12.1-19.E and CatOS 7.6.1)


New Member

Re: Routing advice

Let's break this problem down into two parts.

#1. If you are using multicast in your network outside of then you would need to enable multicast routing on your MSFC. For reference, /24 is a reserved multicast range that is used mostly for stuff like HSRP and OSPF, etc (but not always Cisco protocols) and is usually restricted to the local subnet the multcast orignates on.

#2 The Cat 6509 automatically runs MLS. In fact, you cannot disable it. Also, with the version of IOS you are using on the MSFC, CEF is also on automatically and cannot be turned off globally. You can turn it off on a per-interface basis, but I really think CEF is what you want to stick with. CEF as a switching methodology is way better than process and other kinds of switching. IMHO, most people buy the Cat6509 for its powerful features and moving lots of packets. CEF and the 6509 go very well together. Of course, you could argue with MLS that only the first packet gets truly "routed" by the MSFC and the rest are switched using MLS. We have many 6590s on our network and we use CEF and have not had any issues to date. So to answer your CEF question in a roundabout way, copy your config to a text file and remove all the "no ip route-cache cef" statements and CEF will run on the MSFC automatically. Then paste this into your factory-defaulted MSFC config.