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network flooding during SMB copy

Olivier_1968
Occasional Contributor

network flooding during SMB copy

Hello All,

Let me describe my network, there is a switch "A" (2650) with a "source" server (w2K3) connected on port 1, there is another switch "B" (2824) with a "destination" server connected on port 1, port 2 is connected to another switch "C" 2650 where Desktop are connected, port 3 is connected to another switch"D" 2650 where desktop are connected. Switch A and B are connected together through a 2G trunk.

I use a software called Acronis which give you the possibility to boot your server from a CD and allow you to restore a backup stored on another server (the boot cd is based on a linux boot).

So the goal is to boot my server "destination" from Acronis CD and to restore a backup from "source" server, it seems working fine but after around 9gb transfered from "source" to "destination" the full network is completly flooded by packet coming from backup restoration from source to destination, even a desktop connected to a switch C or D is completly flooded, I ran wireshark from a desktop connected to switch C and I saw huge number a packet coming from "source" to "destination" it was not mutlicast, broadcast or unicast packet , just TCP packet.

I tried it many time and every time it's the same probleme, i tried a windows big file copy beetween server "source" and "destination" and it work perfectly no network flooding.



According to Acronis technical team the restoration based on linux Cd boot is a Samba copy throught SMB.



If anyone has an idea to stop this network flood i will be really happy !!!!



Thanks in advance



Olivier
3 REPLIES
Pieter 't Hart
Honored Contributor

Re: network flooding during SMB copy

Inspect the network capture made with wireshark.
Check here if the MAC-adresses are not used multiple times on your network.

This could happen if you restore an image multiple time to different servers and the MAC-adress is contained in the image.
(depends on OS and it's config).

The switch will get confused about what port really "owns" this address and may flood the data to all ports.

Olivier_1968
Occasional Contributor

Re: network flooding during SMB copy

Hi Peiter,

Thanks for your reply, I checked the Wireshark capture but unfortunatly there is no duplicate MAC.


regards,

Olivier
Pieter 't Hart
Honored Contributor

Re: network flooding during SMB copy

Hi Olivier,
>>> Switch A and B are connected together through a 2G trunk. <<<
I assume this means you've got 2 links betweeen switches A and B?

1) What happens if you disable/diconnect one of these links in the trunk and then do the restore?

If this behaves normal, maybe the switches think different than you about the trunk.
=> inspect this trunk config,

2) with both links active do the restore and list the mac-adress table of the switch.
maybe this gives a hint why packets are flodded to other ports.