etherstub - backup interface?

Krishna Yenduri

2011-10-26 22:26:32 UTC

Post by Jens Elkner
Hi,
is it possible to tell etherstub, that one link is the backup for
another?

etherstub is really a stub and you can not create it
with any datalinks. So, the above is not possible.

One option here is to create vnic1 on top
of aggr0 and vnic2 on top of aggr1 and assign both of them
to Zone A. You can then use IPMP on top of the VNICs
in Zone A. You can repeat this for all the zones by
creating more VNICs on top of aggr0 and aggr1.

Regards,
-Krishna

Post by Jens Elkner
What I have in mind is simplifying/uniform zone setup/connectivity ->
CampusA || || CampusB
+------------------+ 2x10G +--------------------+
| Cisco 6509/3560X |<=================>| Cisco Nexus 5010 |
+------------------+ +--------------------+
Uplinks: ^ ^ ^ ^
_________ | | 2x1G _________________________ | | 2x10G ______________
/ \V/ \V/ /
/ T T /
\ | aggr0 | aggr1 \
\ v v \
\ +---------------------------------------------+ \
/ | etherstub es0 | /
/ +---------------------------------------------+ /
/ ^ ^ /
\ | vnic z0 ... | vnic zN \
\ v v \
\ _________ _________ \
/ / Zone A / ... / Zone N / /
/ /________/ /________/ /
/ X4270M3 /
|_____________________________________________________________________|
Since one can't create vnic's on (even link based) IPMPs, I think [at
least in theory] an etherstub provides the best flexibility (e.g. no
need to shutdown zones just for changing uplinks, no need to config
IPMP in each zone, less vnic to maintain, etc.). However, to avoid Loops
(no STP) I need to tell etherstub, that it should use the backup link
aggr0 only, if aggr1 is down (similar to linkbased IPMP or cisco's
"switchport backup interface")...
Last but not least: IIRC somewhere I've read, that using etherstubs is not
really recommended wrt. performance. Has anybody already done some tests
to get a feeling, how much perf drop one should expect ?
Regards,
jel.