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chrisweaver_152's avatar
chrisweaver_152
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May 09, 2014

Big-IP VE with a single interface, for Navisite

I'm trying to install a Big-IP LTM VE in the Navisite cloud. They only give us one interface. I've seen a couple of other posts where people got a single interface working for a physical server by configuring with the console cable, then assigning the one interface to Internal and using that from then on. Obviously this isn't an option for a virtual machine....

 

Anyone have any suggestions? It seems to be a chicken-and-egg problem.

 

I tried creating an alias for eth0 (eth0:0) and I was able to assign an IP to it using ifconfig, but the Big-IP GUI doesn't see it as an interface. (It doesn't see it at all.)

 

So here's another question: how does the Big-IP detect and maintain interfaces? I see the VLANs in /config but not the interfaces themselves (i.e. the MAC addresses). The Big-IP seems to ignore what's in /etc/sysconfig/network-scripts. (It's a Redhat VM.)

 

5 Replies

  • Kevin_K_51432's avatar
    Kevin_K_51432
    Historic F5 Account

    Hi Chris, The eth0 port is for out of band (management) traffic or access. TMM uses interfaces such as 1.1, 1.2 to create vlans and pass traffic using virtual servers and pools. You can see these with "tmsh show net interface".

     

    Hopefully these documents can offer some of the details you are looking for:

     

    Overview of the management network:

     

    https://support.f5.com/kb/en-us/solutions/public/13000/200/sol13284.html

     

    Creating vlans via tmsh (cli):

     

    https://support.f5.com/kb/en-us/solutions/public/14000/900/sol14961.html?sr=37246881

     

    Kevin

     

  • That was interesting, thanks. But it didn't tell me how to get TMM to assign an interface to an alias interface. I checked the help with "net create ?" and it doesn't look like that's an option with tmsh.

     

    So how does TMM detect interfaces? I'm still hoping there's some way I can fake one.

     

  • Chris, the management and TMM interfaces are very different. If all you have is a management interface you can't really do anything other than manage the box, you can't load balance through it.

     

    The TMM interface would be assigned in the hypervisor, presumably by Navisite. If they won't provide you a TMM interface then really they haven't sold you a working, usable product.

     

  • Well no... the "physical" interfaces are assigned at the hypervisor, and Big-IP sees them as eth0, eth1, etc. This part is standard Linux stuff. It looks like TMM creates other interfaces to ride on top of those.

     

    For example, I created a Big-IP VE in my lab and gave it three interfaces, and I can see them as eth0, eth1, and eth2. Then I see additional interfaces that TMM must be managing: tunl0, mgmt_bp, tmm0, internal, external, socks-tunnel, and http-tunnnel (whew).

     

    Problem is, Navisite only gives me one interface (eth0). I have to assign that to Management so I can get in. So I was hoping to fake a new interface by piggybacking on the one I have.

     

    BigIP supports VLAN tagging, but Navisite doesn't support that either. So I was hoping to fake an eth1 interface by using an alias on eth0. I created an alias (eth0:0) but TMM doesn't see it.

     

    So I was wondering how TMM knows interfaces are there. Is there is a file I can create to fake a new eth1 and point it to eth0:0? Or maybe there some magic I can add to bigip_base.conf to do the same thing?

     

    If I can't make this work, they will probably make me use Netscaler... and no one wants that. :P

     

  • Chris,

     

    You cannot, through any means I'm aware of, use eth0 as a TMM interface I'm afraid. Even if you somehow came up with some sort of genius hack the performance would be extremely poor as you'd be running all the traffic in through the HMS (the Linux OS that provides management), then into TMM and back out again. Not an optimal path.

     

    I appreciate it all looks like 'normal' Linux but the HMS and TMM are two very different things and you won't get anywhere thinking you can 'do something' in Linux; TMM is in charge as it were.

     

    The system loads the interface list on start-up and indeed stores information (such as MAC addresses) in the bigip_base.conf file.

     

    Unless you can get a second vNIC from the hosting provider I guess Netscaler it will have to be.