Ghost Solution Suite

Their is a beleif in our IT dept that when they set up GSS then cant get it to work through 3 com switches. Therefore they have ordered a hub..lol to use it. I havent looked at it myself but this has to sound like one of the most ridiculous excuses ever. What does anyone think about this.

Masterchief

You're right to be skeptical; the GSS product does in general work fine with switches, with two caveats.

One minor caveat is that we recently fixed a small bug in the 2.0 product which introduced a bug caused by some NICs and some switches taking an extraordinarily long time to negotiate line speed. We have a fix for that.

The other caveat is that GSS is really set up to make use of IP multicasting and that's not something many people have become familiar with configuring in their switches and routers (since relatively few products really make use of it, and probably won't until IPv6 is more widespread).

To support multicasting in an environment with managed switches, you initially need to deal with two things - turning on IGMP snooping in the switch (this is the manufacturing default for most managed switches), and turning on IGMP querying in the upstream router (this is a basic part of the IGMP specification, but it's NOT normally a default option).

Once you deal with those basics, there may be a little more to do to ensure that the network as a whole runs smoothly. For instance, turning on IP multicast does mean that traffic can flow a little differently in your network, and that's especially true of the Ghost imaging traffic. Depending on the size and shape of your network - and the quality of the switching and routing equipment you have - you might need to educate your network people about how to deal with it.

For instance, once you enable IGMP, the switch will generally always direct copies of all the multicast traffic to your router (even if it doesn't necessarily need to be) so that the multicast groups can span subnets - a really underpowered router might not be able to cope with that load, and so you might need to filter the imaging traffic in the managed switch to take that load off the router.

Generally though, provided you're running decent equipment, using IP multicast will signficantly boost the efficiency of Ghost operations and actually drastically reduce the amount of load Ghost introduces to the network. There's a good guide to it here at the Cisco site.

Hi Nigel,

I was hoping you would say that. Multicasting is necessary to allow clients to traverse subnets without having to manually tell the client where the server is.

Im sure that if you guys forgot to allow switches to be used then the product would die in the market place quicker than the Sinclair C5. Although the guys setting up GSS in our place think multicast is getting 50 IT staff to manually build pc's in one go :)

thanks