Station Imaging And Network Traffic Saturation

[DaveP]

Removed.

[Ric_]

Is it possible that you are multicasting across all the sites when you image the machines?

It may be a good idea to make sure that the three networks are on 3 different subnets... at least this way the traffic won't 'leak' between schools.

[DaveP]

Removed.

[GrumbleDook]

Directed broadcast is actually a function of Multicast really ... but designed for networks that span more than one subnet or not able to multicast ... but is still pushing packets to each and every machine.

If you are using GhostCast server (not sure in V7.5) then you can throttle this ...

Or you can go back to multicast and just turn off broadcast packets at your switch (should be relatively easy on 3Com and HP kit ... rtfm though) for those rooms that are not being imaged. We have had to do this before when using PowerCast (part of DeployCentre whcih was bought up by Symantec to be included in newer versions of Ghost).

Some information on data throttling is available here.

[DaveP]

Thanks GrumbleDook,

For clarity we do not use the Ghost Console. At the server the image is served out from the Command Prompt. The article does look interesting, but I wil not be able to check things until tomorrow, as I am not at school at the moment.

[DaveP]

OK I had an idea overnight and here it is: Server3 (S3) is the Ghost server. It has two jobs: Ghost image serving and hop on point for Our supplier. I can get Our supplier to join at Server1 (S1) when required. This leaves S3 just doing Ghost. I propose that I move S3 to a new domain, say OurDomain2, on a private IP range and separate subnet mask.

When imaging the traffic then won't bleed across the networks and although the amount of traffic on the stuctured cable network is the same OurDomain1, OtherSchoolDomain1, OtherSchoolDomain2, ConsortiumDomain,.... all ignore the traffic because it doesn't relate to them.

Is this idea going to work if I put it in place?

[GrumbleDook]

A tad complicated ...

I am trying to remember back to someone with a similar situation ... it might have been in the newsgroups (probably uk.education.schools-it).

They put a second NIC in the Ghost server and had all ghost traffic going through that. That NIC went to a second VLAN. When they wanted to image a machine they put the port it went into onto the 'imaging' VLAN and the VLAN was throttle so as not to hammer the network ... I have no idea what kist they were using on the network but it was obviously managed ... is this a possible option for you?

[DaveP]

Could be: The server already has two network cards in: Break up the teamed cards and move one card over to the new IP range and get that to handle the Ghosting sessions (?)

[j17sparky]

Sorry im not reading all the poss but do your switchs support filtering multicasts?

Our HP procurve ones do so i am able to image as much as i want without any/much effect on the network

[DaveP]

Sorry im not reading all the poss but do your switchs support filtering multicasts?

Our HP procurve ones do so i am able to image as much as i want without any/much effect on the network

Unfortunately we use 3Com (I would prefer Cisco). That aside looking at the switches I can see in Device view:

Bridge/Multicast Filter/IGMP/Snoop Mode

IGMP Multicast Filtering is enabled. I suspect this is true for all of the switches, because apart form giving them an IP address and naming them very little other configuration has been done to them, so I supsect this is a default setting. However this is 3Com I am dealing with so I will do some more checking (on more switches)

[JimTheGeek]

I have the same problem, you are not along friend