11-17-2008 07:32 AM - edited 03-06-2019 02:31 AM
Hi
I'm having a problem understanding how to assign an ip address to a switch ethernet interface (6509). I could do the config in two ways i.e:
Method 1:
conf t
interface Vlan 10
ip address 10.50.1.20 255.255.255.0
exit
interface gigabitethernet 1/46
switchport
switchport mode access
switchport access vlan 10
exit
Method 2:
conf t
interface gigabitethernet 1/46
ip address 10.50.1.20 255.255.255.0
exit
Whcih way is the correct way? Also If I go with method 2 how do I know which vlan the port is in?
Thanks
Dan
11-17-2008 07:37 AM
Dan
With method 2 the port is not in a vlan - it is a routed port. By the way you should add "no switchport" under gi1/46 in method 2.
Both are valid and correct ways. You would typically use method 1 when you had a vlan with clients/servers/printers in it.
You would typically use method 2 where you may want to connect the 6500 to another L3 switch and or router and you wanted the link to be a L3 routed link.
Jon
11-17-2008 07:42 AM
Dan
I do not believe that we can say that 1 is the "correct" way, at least not without knowing more about your environment and what your requirements are.
Either of these might be "correct" depending on the situation. Method 2 in which you assign the address directly to the switchport is appropriate when the port is a direct connection to another layer 3 routed device and will create a point to point routed subnet. In this configuration the switchport is not a member of any VLAN, it is just part of a routed subnet.
Method one where you put the switchport into a vlan and assign the IP address to the VLAN is most appropriate when there may be several members of the subnet and you want the address associated with a vlan and not effectively a point to point routed connection.
HTH
Rick
11-17-2008 08:35 AM
HI,
Thanks all for the replies.
I don't have a particular problem it was more of a query that came into my mind. If I imagine a separate router plugged into a switch the connection in the switch will always reside in a particular vlan, why doesn't this case hold up in a multilayered switch?
Thanks
Dan
11-17-2008 08:45 AM
Dan
I have configured setups where a router was connected into a L3 switch where both ends were configured as routed ports. The L3 switch exchanged routes for all it's vlans over the L3 link to the router.
If it is a L2 switch only then you have to put the router port into a vlan because you have no choice as L2 switches do not support routed ports.
However on a L3 switch you have the choice and as i said it depends on what you want to do. So for example if you were designing an access-layer that connected to the distro layer via L3 i would rather use routed ports on both ends than vlans and a L2 link. Major advantage is with L3 link you are not running STP across it.
Jon
11-17-2008 08:49 AM
Dan
I think that you need to think again about your statement: "a separate router plugged into a switch the connection in the switch will always reside in a particular vlan". If you are referring to a layer 2 switch then you are absolutely correct. But in dealing with layer 3 switches that is not necessarily true. As Jon and I have pointed out if you configure the switch interface with no switchport and configure an IP address then the connection from the router to the switch is a routed connection and is not a member of any VLAN.
HTH
Rick
11-17-2008 08:53 AM
Dan
To respond to the part of your answer that you were not facing a particular issue but it was more of a general querry, I think that the right answer is that either approach can be correct. And that the choice of which one is more appropriate depends on the particular situation.
HTH
Rick
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