Hi.

I have 2 6509 switches, with dual supervisor modules.
They are currently connected to each other via an etherchannel trunk.

I am still running a class b subnet, but will be changing to class c,
and using vlans on the switches.

I intend on using hsrp standby groups on the switches for maximum
redundancy.

Can I assume the following config?

CatA_supA
interface vlan1
ip address 192.168.1.250 255.255.255.0
standby 1 priority 200 preempt
standby 1 ip 192.168.1.254

CatA-supB
interface vlan1
ip address 192.168.1.251 255.255.255.0
standby 1 priority 160 preempt
standby 1 ip 192.168.1.254

CatB_supA
interface vlan1
ip address 192.168.1.252 255.255.255.0
standby 1 priority 140 preempt
standby 1 ip 192.168.1.254

CatB-supB
interface vlan1
ip address 192.168.1.253 255.255.255.0
standby 1 priority 120 preempt
standby 1 ip 192.168.1.254

As I am using the standby group number on all routers, they all form
part of the same hsrp group?  How do the hsrp groups talk to each other
- is it using hello ?

I also presume, that any client on either Cat will use the higher
priority interface, even if it's on the other Cat?

Is this a good/valid configuration, or is there a better simpler way to
do it?

My thought is that this provides me with a good redundancy, as if the
primary supervisor goes down, the 2nd will take over, or if an entire
switch goes down, the remaining one can support the default gateway?  I
would stagger the priorities of the various vlans across the
switches/router modules evenly.

Many thanks all....

Pete.

read this please

http://www.cisco.com/en/US/products/hw/switches/ps708/products_configuration_guide_chapter09186a00800da705.html

and this

http://www.cisco.com/en/US/products/hw/switches/ps708/products_configuration_guide_chapter09186a008027e4cd.html

Hi Roman,

thanks for the quick response....

Are these notes pointing at Native IOS on the cat, and not the hybrid
CatOS/IOS?
I am running the later...


Thanks

Pete.

my bad
both links are for "native"

To answer one question HSRP uses hello packets to the multicast add of
224.0.0 2 ( all outers)

A better way would be to use the command: set system highavailability
enable on the Sup cards
and

redundancy
 high-availability
 single-router-mode
on the RSM's or MFC's

That way CatA-supB and CatB-supB only become active when the A sup
fails it makes the configs easier to look at because at any given time
you only have two Sup's active versus all four. However your config's
would work as is.

http://www.cisco.com/en/US/products/hw/switches/ps708/products_white_paper09186a0080088874.shtml
http://www.cisco.com/en/US/products/hw/switches/ps708/products_white_paper0900aecd801c5cd7.shtml

Cool.

I have the system highavail... enabled on the switch (not the MSFC) and
I believe that this sync's the port config (eg vlan info) between the 2
sups in the that chassis.?

So in single router mode, I only configure one sup on each Cat (using
the above config) and it is sync'd to the other sup?

Is the only benefit of doing it this way to reduce the admin overhead
of maintaining 4 configs instead of 2, or this there a more technical
reason?

Many thanks for your replies...


Pete.

If you are running in hybrid mode, you should give consideration to
migrating to native as a first step.

It will help simplify the configuration considerablely

"So in single router mode, I only configure one sup on each Cat (using
the above config) and it is sync'd to the other sup? "

Yes, when you make a config change on the active sup it is automaticly
pushed down to the standby SUP/MSFC thats one of the things I really
like; before, someone would add and interface to the active and not the
standby let alone setup HSRP. Bottom line is it won't be two long
before all 4 of your config's are out of whack.

"Is the only benefit of doing it this way to reduce the admin overhead
of maintaining 4 configs instead of 2, or this there a more technical
reason?"

Thats one reason, but in testing you'll find that HSRP hello's are sent
every 3 sec with a default hold-time of 10 sec and a transition time of
5 to 10 sec, so if a sup card fails youll have about a 25 second
outage, with single router mode the transition from standby sup to
active sup is almost undetectable.

Hi Merv,

Not possible i'm afraid.  We're running hybrid around our organisation,
and this is the 1st installation with 2 cats.

Thanks.

Well your organization is missing out on some very useful features ...

Thank you all for your input.

I'll look into native mode a bit more, but I think the costs of
upgrading all our switches will be too much currently.
I'll also look more into the single router mode options for faster
failover.

With thanks,

Pete.

also take a look at Catalyst modular software for future consideration.

This is key to non-stop forwarding which is where IOS is headed in
higher  end boxes

http://www.cisco.com/en/US/products/ps6550/products_white_paper0900aecd803b2f61.shtml

and

NSF with stateful switch-over
http://www.cisco.com/en/US/products/hw/switches/ps708/products_configuration_guide_chapter09186a0080


BTW how many switches do you have in your network

Hi Merv.

Sorry for the dealy in replying - I though I had posted...

I have 2 cats on my local site, 2 on another, and 1 on a third.
Unfortunately, they all fall under different financial control, with
some being tighter that others!

Many thanks to everyone,

Pete.