imposible to deploy Ipv6 on lan with catalyst 2950t ?

[jorgegonzalezbriceno]

Is it imposible to deploy Ipv6 on Lan enviroment with catalyst 2950T access switch?

Thanks

[Phillip Remaker · Accepted solution]

The Catalyst 2950 will transparently forward packets at layer 2 which contain IPv6 data (as will any switch), but it cannot participate in the Layer 3 IPv6 network.

[Salman Asadullah · Accepted solution]

[similar question was asked in "ask the expert" so posting the same answer here as well]

- snip -

Hello,

This is a common question which comes quite often – What should I do with my old Layer2 switches (e.g. Catalyst 2900, 3900, 5000, etc.)? The simple answer is; IPv6 is transparent on L2 switches so no need to worry about it. However; there are couple cases where you would need to take a closer look.

Rightly asked; one is MLD snooping. Yes, if you are planning to have real IPv6 Multicast deployment then you would need to have products which support MLD snooping at Layer2. If you are not deploying IPv6 Multicast then I would not worry about it much.

Another one is when you have intelligent services on WLAN; may be it’s not Catalyst switch but it’s a AP where you are running intelligent services such as QoS, or ingress ACLs on AP or maybe actual controller based environment where you have thin APs and fat controllers in the back-end, but you have a distributed policy at the edge, if you are doing this and using IPv4 based protocols then you have to make sure that those products supports equivalent configurations for IPv6 capabilities or you would have serious road blocks.

Simple “2 rules of thumb” which I always tell customers:

1. There is no way you put 10lbs of sugar in a 5lb bag.
2. Always have plan/testing/validation/pilot before introducing any new protocol/technology in your production network.

Please take a look at http://www.cisco.com/en/US/prod/collateral/iosswrel/ps6537/ps6553/at_a_glance_c45-625859.pdf and lot of good information regarding Enterprise dual-stack case studies and recommendations at www.cisco.com/go/ipv6. I would recommend you to also work with your Cisco Account and Services teams for smooth Dual-Stack deployment.

Regards,

Salman

[jorgegonzalezbriceno]

Thanks for your answer salman,

I'm worry about flooding on the network (200 catalyst 2950T).

[Salman Asadullah · Accepted solution]

Right concern, if MLD snooping in not supported then IPv6 multicast will be flooded on all ports of the switch.  Please keep this in mind this is exactly the same concept as IGMP snooping in IPv4.

Good luck!

Regards,

Salman

[jorgegonzalezbriceno]

Here is the document for those who need more information:
http://www.cisco.com/en/US/docs/switches/lan/catalyst3750/software/release/12.2_35_se/configuration/guide/swv6mld.html
Understanding MLD Snooping
In IP version 4 (IPv4), Layer 2 switches can use Internet Group
Management Protocol (IGMP) snooping to limit the flooding of multicast
traffic by dynamically configuring Layer 2 interfaces so that multicast
traffic is forwarded to only those interfaces associated with IP
multicast devices. In IPv6, MLD snooping performs a similar function.
With MLD snooping, IPv6 multicast data is selectively forwarded to a
list of ports that want to receive the data, instead of being flooded
to all ports in a VLAN. This list is constructed by snooping IPv6
multicast control packets.
MLD is a protocol used by
IPv6 multicast routers to discover the presence of multicast listeners
(nodes wishing to receive IPv6 multicast packets) on its directly
attached links and to discover which multicast packets are of interest
to neighboring nodes. MLD is derived from IGMP; MLD version 1 (MLDv1)
is equivalent to IGMPv2 and MLD version 2 (MLDv2) is equivalent to
IGMPv3. MLD is a subprotocol of Internet Control Message Protocol
version 6 (ICMPv6), and MLD messages are a subset of ICMPv6 messages,
identified in IPv6 packets by a preceding Next Header value of 58.
Thanks for the answer.
Regards,
George

[jorgegonzalezbriceno]

Thanks for your answer phillip

I'm actually worry about flooding on all ports on access layer switch (2950T), 180sw on my network.