Catalyst 3750-X IPv6 feature support (or lack thereof)

[sylvain.munaut]

I mean seriously ... it's 2013 and AFAICT the 3750-X which is a pretty recent switch still doesn't support some pretty important features when it comes to IPv6.

Things like VRF and PBR are apparently not supported and I'd really need one of them (I can make it work with either, but they're both not supported).

Other things like IPv6 support for BGP are kind of unclear. The manual states that they're not supported but OTOH I've been able to start a BGP process to an IPv6 neighbor, exchange some IPv6 routes and get them into the routing table. Not sure who to trust: the manual or reality ... I mean maybe that feature doesn't work right, or maybe they'll drop it in the next release ...

In this particular instance, my problem is that I have two upstream providers, each with their own range of IPv6 they route to me. Some machine have those IPs (from either range) and I need to route back depending on the source IP. Now I could do that with PBR matching the source IP, but PBR isn't available. Or I could do that with VRF (having the machines assigned to one provider in one VRF and the machines on the other provider on another VRF). But again, not IPv6 VRF ...

Anyone sees another alternative ?

And what should we do to get those features to be implemented soon ?

Cheers,

    Sylvain

[Joseph W. Doherty]

Disclaimer

The   Author of this posting offers the information contained within this   posting without consideration and with the reader's understanding that   there's no implied or expressed suitability or fitness for any purpose.   Information provided is for informational purposes only and should not   be construed as rendering professional advice of any kind. Usage of  this  posting's information is solely at reader's own risk.

Liability Disclaimer

In   no event shall Author be liable for any damages whatsoever (including,   without limitation, damages for loss of use, data or profit) arising  out  of the use or inability to use the posting's information even if  Author  has been advised of the possibility of such damage.

Posting

Yes, the 3750-X series probably has less IPv6 features than other Cisco switch series, but I suspect that because it's really designed/marketed as a basic L3 edge switch.

For better L3 IPv6 support you would need to consider true "routers" (e.g. ASR 1Ks and 9Ks) or "better" L3 switch series, such as the 4500/4900 or 6500/7600 series.

Unfortunately, reality is, often vendors products are often designed not to compete too much with the same vendor's other products.  I.e. if a 3750-X did everything a 4900 does, why buy a 4900?

On the 3560-X/3750-X series, take note what happens to your TCAM resources when you enable a IPv6 SDM template. 

BTW, I'm not saying I like this, it's just what is.  Other network vendor may design/market similarly, some not.  Caveat emptor.

[sylvain.munaut]

Unfortunately I don't think this differentiation has the intended effect ... Because when you have the feature available in IPv4 and not IPv6, I won't be able to justify the cost of the upper line of switch "just" for IPv6 and so instead of Cisco making a new sale of a more expensive switch, I'll just have to drop IPv6 and end up with a network not as modern ... And I would suspect that I'm not alone in that situation and so this is just hurting IPv6 deployment rather than helping new sales.

If you want to really differentiate, then I'd say just don't include the IPv4 feature either. And that would also make the product briefs clearer because right now if you see "Policy Based Routing support" and "IPv6 support", you still have to figure out that those might not work together and probably (like me) only notice it when the HW is already bought ...

You mentionned TCAM usage, and I think this is a much better differentiator between product lines. When I look at the TCAM usage on my 3750-X, it's ridiculously low ... I have very little ACLs or special things running on there but from time to time, I need one special feature, only for a couple of special exception rules that will take a few TCAM entries and that's just not worth getting the upper model. While on the other hand, I can see that being able to apply a lot of rules with lots of special features will be useful for some people and those will be able and willing to pay for it.

Anyway ... just my 2ct ...

[shillings]

According to Feature Navigator, you'll need a Metro Ethernet switch for IPv6 with VRF-Lite. Specifically, the ME3400, ME3400E or 3750 Metro. However, the 3400 and 3750 Metro are now End-of-Life. I can't believe only the 3400E is capable of this feature - there must be alternatives.

Can't see anything definitive for IPv6 with PBR. There is a feature called 'IPv6 VRF Aware PBR next-hop enhancement'. Not sure what this feature actually is, but it's not available in the above mentioned 3400E