Ghost causes the network to stop

[FN-GM]

Hi,

 

When ghosting out the network seems to come to a halt. My first thoughts are to enable IGMP Snooping on the switches but it seems it enabled already. I have attached some screenshots.

 

The majority of switches are Cisco 2950 or 2960.

 

Does anyone have any thoughts please?

 

Thanks

[6Foot2]

If you have a layer 3 switch [not familiar with your Cisco switches] available to you I would look at setting up VLANs [if you don't have them set up already?]

 

Our VLANs eliminated a lot on network-traffic related problems [we were given bad advice about IGMP snoop by a previous provider which was not helping. However what we have now is a network that allows us to Ghost on the network without affecting other classrooms outside the VLAN we are currently Ghosting on]

[witch]

Never been able to Ghost without bringing the network to a halt. Using WDS solved that

[6Foot2]

Never been able to Ghost without bringing the network to a halt. Using WDS solved that

 

We are looking at WDS for our move to Windows 7 over the Summer break. For the time being we are still on Ghost.

[ricki]

HI

 

I used to have this problem with ghost at one of the primary schools I worked at. The way I got round the problem was to turn down the rate the ghost cast server worked at to about 30% and the problem disappeared. Ghost appears to try and use as much band width as it can. Saying that some of the machine would ghost in about 12 mins.

 

Richard

[witch]

Wow - my fastest machines take about 15 mins and as I said, bring the network to a halt. I will remember to slow down the rate if I need to ghost when students are on the network - which often happens as I am part-time

[FN-GM]

Thanks for the input guys. I will see what the crack is tomorrow. We are also using Acronis Snap Deploy and it does the same with that so will have a look if i can turn it down some how.

 

Thanks

[m25man]

Enabling IGMP Snooping alone will not stop the fact that you are trying to send a continuous stream of data from a single source MAC address to multiple MAC addresses at the same time.

 

Visualise on your topology where your ghost images are stored, then where your Ghost Multicast Server is (if not on the same server) and how your packets are going to get to the switch where all of your clients are listening...

 

Unless you have Multiple Trunked Uplinks between all switches there is a good chance that at some point all of your multicast traffic is crossing the same uplink as the rest of your data.

All of your normal traffic such as DNS, Browsing and SMB Traffic cannot pass through these links until the Ghost Server comes up for air!

 

IGMP Snooping simply informs the switch ports that a multicast is taking place and makes all switches in the path aware of the locations of all the other switch ports that are expected to take part in the Multicast session.

With all of the right settings along the route from Ghost Server to client suite its possible for everyone to get through the session with the minimum of pain but it is the shared uplinks are what will choke the network and bring it to it's knees.

 

Quickly sketch a switch map from ghost server to the room cabinet how many hops are there?

How many links are single copper/fibre?

Is is Gigabit to desktop?

 

Your answer will be there somewhere...