Etherchannel on a Voice Gateway

[Brian Carscadden]

We're considering etherchannel on a 2851 voice gateway. The goal is to use both of the dual Gig LAN interfaces for redundancy. Anyone with recommendations please let me know.

Thanks

[paolo bevilacqua]

Why do you want use ethernchannel? to how many switches are you connecting to ?

[mhurley131]

I don't think etherchannel can be used on routers.

If you are looking for redundancy, look towards connecting both interfaces and running a dynamic routing protocol such as EIGRP or OSPF. This will load balance traffic across the equal links, and also provide you with redundancy.

[paolo bevilacqua]

Yes the router supports etherchannel:

http://cisco.com/en/US/tech/tk389/tk213/technologies_configuration_example09186a0080094b0a.shtml

However there is very little redundancy advantage when connecting to a single switch, so better to have multiple connections if possible, instead.

[Brian Carscadden]

Thanks for the reply (again ;-) )

It's a single switch (Cat 4k), but different blades. Combine a nervous customer with a device with two NICs and *presto* you have a client that wants to make the connections redundant. I found the doc for configuring etherchannel between an IOS switch and router. Seems workable, but wanted to get some feedback first.

[paolo bevilacqua]

I think it's also a matter of educating the customer and setting the technical responsibility boundaries.

If you teach customer that port (or blade) failure on either router and switches is practically a non-occurrence with these devices, and the best practices, as defined in the cisco official SRND is to use a single connection, that would suffice.

[Brian Carscadden]

I don't think this is workable due to the nature of voice gateways needing a single IP for registration to Callmanager.

[paolo bevilacqua]

You can have a single IP address when you are connected to for example, two switches. This address you configure on BVI interface and place the LAN interfaces in the corresponding bridge-group. Bridge irb is used for that.

One interface will be blocked by STP but you have redundancy on the two switches if interested in that.

[Brian Carscadden]

Saw this, thanks. In this case it's just one switch.

[AJAZ NAWAZ]

L3 SVI interface (aka port-channel interface), allows you to configure IP address.

<http://www.cisco.com/univercd/cc/td/doc/product/l3sw/2948g-l3/rel_12_0/config/ether_ch.htm>

hth,

Ajaz

[Rajesh Kalra]

Hi,

Instead of Etherchannel, how about using the backup interface command on the second NIC of the router.

The benefit is we can use the same IP on the second NIC as the first/primary NIC.

The backup interface remains in standby mode and becomes alive only when the primary NIC is down.When the primary NIC comes up the secondary automatically goes in standby mode.

Advantages : "Backup interface" command is independent of routing protocols. That is, it does not depend on routing protocol convergence, route stability and so on.

Each of the voice gateway NICs can be conencted physically to LAN swiches.

The Voice gateway protocol which can be easily used with this setup is H323 or SIP, not sure on MGCP though.

Only thing is the calls active calls will drop when the primary interface goes down, or comes back again(the secondary NIC goes to standby mode) which is the normal behaviour.

Can you please feedback on the usage of "backup interface" command for configuring NIC resilience on the voice gateway?

[paolo bevilacqua]

You are responding to a 6 years old thread. You should open new threads for new problems.

[Brian Carscadden]

I respectfully disagree. If old threads are useless then Cisco should just delete them after a given time. Since they appear in search results, they're relevant, period.

Yes, it's a bit late for me to use the info (since I opened the thread), but perhaps someone else might find this useful.

Regards,

Brian