ASA 5520 Failover question

[chrish]

I am setting up redundant 5520's for the first time and have a question on the failover interface. I have read but can't now find info on best practices regarding the management interface as well as the failover interface. My plan is to implement stateful failover in an Active/Standby config. I would like to use the Management interface for use as the failover also. Is this wise? If so should I use subinterfaces? Are there any gotchas I need to be aware of?

Thanks in advance

[grant.maynard]

Cisco say that for stateful failover you should use an interface equal to the highest bandwidth. So for an ASA that would be a GE. However you may want to gamble and use a 100M instead, I have done this before.

It is ok to use subinterfaces for the hellos and stateful info, but I wouln't share that interface with anything else.

[chrish]

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I'm sorry I don't quite understand this sentence.If I am using a subinterface wouldn't that imply that I am sharing the interface(with another subinterface)? Or are you saying on this particular subinterface I shouldn't share traffic?

[scarpacci21]

I just installed two ASA 5520's with statefull failover in an Active/Standby configuration. I did not want to sacrafice one of the ge int's for this. I'm using the management interface and am graphing the bandwidth usage with MRTG. So far after one full business day, its only consumed 100kb on the link. Without knowing your traffic utilization, it's hard to say if you'll run into problems but it peaked with a little over 9000 connections and 100kb was all it needed. Chances are you'll be ok.

[grant.maynard]

I meant that on one physical interface you can use subinterfaces for hellos and stateful, but don't add any other subinterfaces to that interface trunk.

[chrish]

OK. I really appreciate your help. Thank you.

So is this just a BW issue?

My configuration is going to be rather simple. I should be passing a relatively low amount( in packets or streams) of high volume data.Bandwidth wise I will be needy but in amounts of packets or conversations pretty low. Relatively straight forward NAT rules.I will also only be using 1 context with 4 or 5 interfaces. It would seem my this level of use should not be passing large amounts of stateful data.