question regards to route and L3 switching?

[julxu]

Hi

can I ask a easyquestion?

I have a cat6500,

  a css11506, on vlan111 as servers subnet direct linked to the cat6500.

  there is a DB server on vlan 222 also direct connect to the cat6500; there also has a backup server located on vlan 111, backup for DB server.

  on cat6500, there is a static route "ip route" to set route subnet on vlan 111 go to css11506.

  the all servers on subnet vlan111 has setup default router is css11506. so, any server in vlan 111 will use router server-css11506-cat6500.

question:

 if the DB server doing backup to backup server on vlan 111, what actually traffic go?

     after routing to get destination on both servers, I thought it should go to ethernet address to ethernet address, that is the traffic only go through cat6500 two ports of the servers, am I right? The backup traffic will not go throught css11506 packets by packets, am I right?

Any comments will be appreciated

Thanks in advance

julxu

[Jon Marshall · Accepted solution]

It's not entirely clear what your setup is.

But if you have a backup server in vlan 111 with it's default gateway of the CSS and you have a DB server in vlan 222 with presumably it's default gateway an SVI on the 6500 then all backup traffic between the two will go through the CSS.

It has to because the two servers are on different vlans and therefore the traffic must be L3 switched.

That is why in these sort of environments you often have dedicated network cards in the servers just for backup and you place these on a separate vlan, often the same vlan as the backup server so traffic does not have to go via the main production path.

Jon